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Christopher D M Fletcher

Publications and source records attributed to Christopher D M Fletcher.

At least 19 recordsLinked to original sources
PubMed2007

Caveolin 1 is overexpressed and amplified in a subset of basal-like and metaplastic breast carcinomas: a morphologic, ultrastructural, immunohistochemical, and in situ hybridization analysis.

PURPOSE: The distribution and significance of caveolin 1 (CAV1) expression in different breast cell types and role in breast carcinogenesis remain poorly understood. Both tumor-suppressive and oncogenic roles have been proposed for this protein. The aims of this study were to characterize the distribution of CAV1 in normal breast, benign breast lesions, breast cancer precursors, and metaplastic breast carcinomas; to assess the prognostic significance of CAV1 expression in invasive breast carcinomas; and to define whether CAV1 gene amplification is the underlying genetic mechanism driving CAV1 overexpression in breast carcinomas. EXPERIMENTAL DESIGN: CAV1 distribution in frozen and paraffin-embedded whole tissue sections of normal breast was evaluated using immunohistochemistry, immunofluorescence, and immunoelectron microscopy. CAV1 expression was immunohistochemically analyzed in benign lesions, breast cancer precursors, and metaplastic breast carcinomas and in a cohort of 245 invasive breast carcinomas from patients treated with surgery followed by anthracycline-based chemotherapy. In 25 cases, CAV1 gene amplification was assessed by chromogenic in situ hybridization. RESULTS: In normal breast, CAV1 was expressed in myoepithelial cells, endothelial cells, and a subset of fibroblasts. Luminal epithelial cells showed negligible staining. CAV1 was expressed in 90% of 39 metaplastic breast carcinomas and in 9.4% of 245 invasive breast cancers. In the later cohort, CAV1 expression was significantly associated with 'basal-like' immunophenotype and with shorter disease-free and overall survival on univariate analysis. CAV1 gene amplification was found in 13% of cases with strong CAV1 expression. CONCLUSIONS: The concurrent CAV1 amplification and overexpression call into question its tumor-suppressive effects in basal-like breast carcinomas.

Breast↗
PubMed2007

Epithelioid variant of myxofibrosarcoma: expanding the clinicomorphologic spectrum of myxofibrosarcoma in a series of 17 cases.

Myxofibrosarcoma (MFS) is one of the most common soft tissue sarcomas of elderly patients and has a predilection for the limbs. Herein, we report a previously undescribed variant of MFS showing epithelioid morphology. Seventeen cases diagnosed as epithelioid MFS were retrieved from the authors' files from among 570 cases of MFS. Hematoxylin and eosin-stained sections were reexamined and immunostains for pan-keratin (15 cases), S-100 protein (15), desmin (15), and alpha-smooth muscle actin (13) were performed. Nine patients were men and 8 were women (age range 43 to 89 y; median 63.5). Fifteen patients presented with a mass, and in 2 of these there was also pain. Duration of symptoms varied from 1 to 24 months (median 3). Tumor size ranged from 2 to 15 cm (median 6.75). In 10 cases, the tumor was located in subcutaneous tissue and in 6 cases it was subfascial. The majority of the tumors were located on the limbs (8 lower extremities and 6 upper extremities) followed by neck (1), scalp (1), and trunk (1). Follow-up was available for 14 patients (range 2 to 240 mo; median 16). Twelve patients were treated by surgery followed by chemotherapy and/or radiation (8 cases). One patient received chemotherapy after an incisional biopsy and 1 patient was treated by surgery alone. Ten patients (71.4%) developed local recurrences. Seven patients (50%) developed metastases to lungs or retroperitoneum. Five patients (35.7%) have died of disease so far. Two patients were lost to follow-up. Morphologically, 14 cases were high grade, 2 were intermediate, and 1 was low grade. Tumors were characterized by a multinodular, infiltrating growth pattern with alternation of hypercellular and hypocellular myxoid areas; the latter showed prominent curvilinear vessels. Neoplastic cells were arranged singly and in small clusters in the myxoid areas or formed sheets in the hypercellular areas, where they showed epithelioid morphology with round nuclei, vesicular chromatin, prominent nucleoli, and moderate amounts of eosinophilic cytoplasm. The epithelioid areas were generally multifocal with admixed areas of conventional MFS. Immunostains were negative for all markers studied. Differential diagnosis included carcinoma, melanoma, myoepithelial carcinoma, pleomorphic liposarcoma, and pleomorphic rhabdomyosarcoma. In conclusion, epithelioid MFS is a rare variant of MFS, accounting for <3% of MFS in consultation material. Its natural history seems more aggressive than usual high-grade MFS, with approximately 70% local recurrence and 50% metastases, even within a relatively short follow-up period.

Adult↗
PubMed2006

Incidence patterns of soft tissue sarcomas, regardless of primary site, in the surveillance, epidemiology and end results program, 1978-2001: An analysis of 26,758 cases.

Soft tissue sarcomas (STS) are a heterogeneous group of uncommon tumors that show a broad range of differentiation that may reflect etiologic distinction. Routine tabulations of STS are not morphology-specific. Further, the lack of inclusion of sarcomas arising in all organs in most standard evaluations underestimates the true rates. We analyzed the 1978-2001 Surveillance, Epidemiology and End Results program incidence rates of STS regardless of primary site, except bones and joints, using the 2002 criteria of the WHO classification. There were 26,758 cases available for analysis. Leiomyosarcomas accounted for 23.9%, malignant fibrous histiocytomas 17.1%, liposarcomas 11.5%, dermatofibrosarcomas 10.5%, rhabdomyosarcomas 4.6% and angiosarcomas 4.1%. Almost half (47.9%) of the sarcomas arose in the soft tissues, 14.0% in the skin and 7.0% in the uterus. Overall, incidence rates were highest among black women (6.26/100,000 woman-years) and the lowest among white women (4.60/100,000). Age-adjusted rates increased at 1.2% and 0.8% per year among white males and females, respectively, both trends statistically significant, while rates among blacks declined slightly. About 40% of leiomyosarcomas among women were uterine in origin, with a black/white rate ratio of 1.7. This rate ratio increased to 2.0 when we accounted for the lower prevalence of intact uteri among black compared to white women. Total STS rates rose exponentially with age. Rates for both uterine leiomyosarcoma and dermatofibrosarcoma increased rapidly during the childbearing years, peaking at about age 40 and 50, respectively. Incidence patterns of STS varied markedly by histologic type, supporting the notion that these tumors may be etiologically distinct.

Adolescent↗
PubMed2006

Molecular correlates of imatinib resistance in gastrointestinal stromal tumors.

PURPOSE: Gastrointestinal stromal tumors (GISTs) commonly harbor oncogenic mutations of the KIT or platelet-derived growth factor alpha (PDGFRA) kinases, which are targets for imatinib. In clinical studies, 75% to 90% of patients with advanced GISTs experience clinical benefit from imatinib. However, imatinib resistance is an increasing clinical problem. PATIENTS AND METHODS: One hundred forty-seven patients with advanced, unresectable GISTs were enrolled onto a randomized, phase II clinical study of imatinib. Specimens from pretreatment and/or imatinib-resistant tumors were analyzed to identify molecular correlates of imatinib resistance. Secondary kinase mutations of KIT or PDGFRA that were identified in imatinib-resistant GISTs were biochemically profiled for imatinib sensitivity. RESULTS: Molecular studies were performed using specimens from 10 patients with primary and 33 patients with secondary resistance. Imatinib-resistant tumors had levels of activated KIT that were similar to or greater than those typically found in untreated GISTs. Secondary kinase mutations were rare in GISTs with primary resistance but frequently found in GISTs with secondary resistance (10% v 67%; P = .002). Evidence for clonal evolution and/or polyclonal secondary kinase mutations was seen in three (18.8%) of 16 patients. Secondary kinase mutations were nonrandomly distributed and were associated with decreased imatinib sensitivity compared with typical KIT exon 11 mutations. Using RNAi technology, we demonstrated that imatinib-resistant GIST cells remain dependent on KIT kinase activity for activation of critical downstream signaling pathways. CONCLUSION: Different molecular mechanisms are responsible for primary and secondary imatinib resistance in GISTs. These findings have implications for future approaches to the growing problem of imatinib resistance in patients with advanced GISTs.

Antineoplastic Agents↗
PubMed2006

Critical diagnoses (critical values) in anatomic pathology.

Similar to critical values in clinical pathology, occasional diagnoses in surgical pathology and cytology may require urgent contact of the physician to facilitate rapid intervention or treatment. However, there are no established critical value (critical diagnosis) guidelines in anatomic pathology. As discussed herein, the Association of Directors of Anatomic and Surgical Pathology (ADASP) believes that establishing anatomic pathology critical diagnosis guidelines represents a practice improvement and patient safety initiative. The ADASP also recognizes that a generic anatomic pathology critical diagnosis guideline such as this should only be used as a template because the list needs to be customized at each individual hospital after consultation with relevant clinical services. Based on surveys of the membership of the ADASP, this document provides examples of possible critical diagnoses in anatomic pathology.

Diagnostic Errors↗
PubMed2006

Surgical management of advanced gastrointestinal stromal tumors after treatment with targeted systemic therapy using kinase inhibitors.

PURPOSE: While targeted inhibitors of tyrosine kinase activity demonstrate dramatic efficacy in the majority of patients with advanced gastrointestinal stromal tumors (GISTs), cure remains elusive and resistance to systemic therapy is a challenge. To assess the role of surgery in multimodality management of GISTs, we studied postoperative outcomes in patients treated with targeted kinase inhibitors for advanced GIST. METHODS: We evaluated outcomes in a single institution series of 69 consecutive patients who underwent surgery for advanced GISTs while receiving kinase inhibitors. Patients were categorized based on extent of disease before surgery (stable disease, limited disease progression, generalized disease progression) and surgical result (no evidence of disease, minimal residual disease, bulky residual disease). RESULTS: Disease status before surgery was associated with surgical result (P < .0001; median follow-up, 14.6 months). After surgery, there was no evidence of disease in 78%, 25%, and 7% of patients with stable disease, limited progression, and generalized progression, respectively. Bulky residual disease remained after surgery in 4%, 16%, and 43% of the patients with stable disease, limited progression, and generalized progression. Twelve-month progression-free survival was 80%, 33%, and 0% for patients with stable disease, limited progression, and generalized progression (P < .0001). Twelve-month overall survival was 95%, 86%, and 0% for patients with stable disease, limited progression, and generalized progression (P < .0001). CONCLUSION: Patients with advanced GISTs exhibiting stable disease or limited progression on kinase inhibitor therapy have prolonged overall survival after debulking procedures. Surgery has little to offer in the setting of generalized progression.

Adult↗
PubMed2006

Sclerosing paraganglioma: report of 19 cases of an unusual variant of neuroendocrine tumor that may be mistaken for an aggressive malignant neoplasm.

Nineteen cases of a distinctive variant of paraganglioma characterized by extensive collagen deposition resulting in a pattern of growth that resembled an invasive malignant neoplasm are described. The patients were 3 men and 16 women, 32 to 69 years of age (mean, 50.5 years). The tumors were located in the carotid body region, parapharyngeal region, and mediastinum. Tumor size ranged from 2 to 6 cm in greatest diameter. Grossly, the tumors were described as rubbery to firm, tan-red, and with extensive areas of sclerosis. Histologic examination showed nests and cords of tumor cells separated by broad bands of fibrous tissue. The tumor cells ranged from round to polygonal with abundant cytoplasm to elongated spindle cells with scant cytoplasm. Nuclear cytomegaly was present focally enhancing the atypical appearance of the tumor cell population in 17 cases. Mitoses were sparse (<1 x 10 HPF), and there was no evidence of necrosis in any of the cases. Foci of vascular and perineural invasion were present in 2 and 4 cases, respectively. The most striking morphologic feature was the presence of irregular cords and bands of hyalinized fibrous tissue that compartmentalized the lesion into irregular nests, islands, or cords of tumor cells, imparting them with an infiltrative appearance. All the tumors showed positive immunostaining for chromogranin, synaptophysin, and monoclonal neuron specific enolase. S-100 protein stains identified a sustentacular cell network, whereas cytokeratin AE1/AE3 was negative in all cases. Clinical follow-up in 14 cases, ranging from 2 months to 20 years (mean follow-up, 6.6 years) showed evidence of local recurrence in 2 cases and the development of a separate tumor in the contralateral neck in 1 case. The remainder of patients were free of recurrence or metastasis following simple local excision. Because of the prominent sclerosis, a diagnosis of an invasive malignant neoplasm was initially considered in the majority of cases. Sclerosing paraganglioma should be included in the differential diagnosis of sclerosing lesions of the head and neck region and mediastinum. Appropriate immunohistochemical stains may be of aid for establishing the correct diagnosis.

Adult↗
PubMed2006

Intraarticular nodular fasciitis--a rare lesion: clinicopathologic analysis of a series.

Nodular fasciitis is a benign myofibroblastic proliferation with a predilection for the subcutaneous tissues of the upper extremities, trunk, and head and neck of young adults. Nodular fasciitis is not generally recognized to arise within joints. In this study, the clinicopathologic and immunohistochemical features of 10 cases of intraarticular nodular fasciitis are described. Six patients were female and 4 were male, with a median age of 33 years (range, 9-50 years). Lesional size ranged from 2 to 4 cm (median, 2.6 cm). Seven tumors arose in the knee, 2 in the hand, and 1 in the ankle. Most patients complained of joint pain; 4 presented with a palpable mass. Only 1 patient reported antecedent trauma. The duration of symptoms prior to surgery ranged from 2 months to 1 year (median, 6 months). The clinical differential diagnoses included giant cell tumor of tendon sheath, pigmented villonodular synovitis, synovial chondromatosis, inflammatory arthritis, and lymphoma. Grossly, the lesions were solid, nodular, rubbery, or firm masses. Histologically, all tumors were circumscribed but unencapsulated and showed typical features of nodular fasciitis, being composed of cytologically bland plump spindle cells arranged in short, intersecting bundles within a variably loose myxoid to collagenous stroma, containing extravasated red blood cells and scattered lymphocytes. Five lesions showed prominent stromal hyalinization, in 2 cases keloidal in appearance. In 4 cases, the tissue at the periphery of the lesion showed hemosiderin deposition. By immunohistochemistry, all tumors examined were positive for SMA, 1 was positive for desmin, and all were negative for caldesmon and S-100 protein; none showed nuclear staining for beta-catenin. Clinical follow-up information was available for 5 patients, ranging from 2 to 86 months. No lesion recurred. In summary, intraarticular nodular fasciitis occurs most commonly in the knees of young adults, and often appears to have a somewhat longer preoperative duration than typical subcutaneous or intramuscular nodular fasciitis. Intraarticular lesions show morphologic features similar to other cases of nodular fasciitis, with the exception that stromal hyalinization and adjacent hemosiderin deposition are common, likely attributable to frictional trauma in this location.

Adolescent↗
PubMed2006

Spindle cell (sarcomatoid) carcinoma of the breast: a clinicopathologic and immunohistochemical analysis of 29 cases.

Spindle cell (sarcomatoid) carcinoma of the breast is a rare variant of breast cancer that has been classified under the broad rubric of metaplastic carcinoma. Because the term "metaplastic carcinoma" comprises a heterogeneous group of tumors, it has been difficult to reliably predict biologic potential or to determine optimal therapy. To better characterize the spindle cell subset of metaplastic breast carcinomas, we reviewed 29 cases. All patients were adult females ranging from 40 to 96 years of age (median, 68 years). Tumor size ranged from 1.5 to 15 cm (median, 4 cm). Treatment was by excision and/or mastectomy with axillary node evaluation in most cases, often combined with postoperative radiation and/or chemotherapy. All cases were clinically of breast origin, showed >or=80% spindled/sarcomatoid morphology, and demonstrated keratin positivity and/or close association with ductal carcinoma in situ. Immunohistochemical studies showed evidence suggesting myoepithelial differentiation as exhibited by immunoreactivity for smooth muscle actin, cytokeratin 14, and p63 in a subset of cases (39%). Twenty-seven cases exhibited pure spindled or sarcomatoid morphology of variable appearance and nuclear grade, whereas 2 contained high-grade invasive ductal carcinoma comprising <or=20% of the tumor mass. Two cases exhibited heterologous elements (1 rhabdomyosarcoma and 1 with both chondrosarcoma and osteosarcoma) and 4 were associated with ductal carcinoma in situ. Follow-up data were available on 24 of 29 patients (range, 1-120 months; median, 20 months). Of 20 cases in which axillary nodes were biopsied, definitive nodal metastases were identified in only 1 (5%), and this was in a case with a significant component of invasive ductal carcinoma. Three patients developed local recurrences. Extranodal metastases occurred in 11 of 24 patients (46%), most commonly to the lungs. Ten of 24 patients (42%) died of disease at a median interval of 11.5 months (range, 1-46 months) and 3 patients were alive with metastatic disease. Eight patients were alive with no evidence of recurrent or metastatic disease (median, 29.5 months). Based on this series, spindle cell/sarcomatoid carcinoma of the breast is a highly aggressive neoplasm with a high rate of extranodal metastases. Purely spindled/sarcomatoid tumors have a significantly lower rate of nodal metastases than conventional ductal and lobular breast carcinomas.

Adult↗
PubMed2005

BRAF mutations are sufficient to promote nevi formation and cooperate with p53 in the genesis of melanoma.

Melanoma is the most lethal form of skin cancer, and the incidence and mortality rates are rapidly rising. Epidemiologically, high numbers of nevi (moles) are associated with higher risk of melanoma . The majority of melanomas exhibit activating mutations in the serine/threonine kinase BRAF . BRAF mutations may be critical for the initiation of melanoma ; however, the direct role of BRAF in nevi and melanoma has not been tested in an animal model. To directly test the role of activated BRAF in nevus and melanoma development, we have generated transgenic zebrafish expressing the most common BRAF mutant form (V600E) under the control of the melanocyte mitfa promoter. Expression of mutant, but not wild-type, BRAF led to dramatic patches of ectopic melanocytes, which we have termed fish (f)-nevi. Remarkably, in p53-deficient fish, activated BRAF induced formation of melanocyte lesions that rapidly developed into invasive melanomas, which resembled human melanomas and could be serially transplanted. These data provide direct evidence that BRAF activation is sufficient for f-nevus formation, that BRAF activation is among the primary events in melanoma development, and that the p53 and BRAF pathways interact genetically to produce melanoma.

Animals↗
PubMed2005

tp53 mutant zebrafish develop malignant peripheral nerve sheath tumors.

TP53 is the most frequently mutated tumor suppressor gene in human cancer, with nearly 50% of all tumors exhibiting a loss-of-function mutation. To further elucidate the genetic pathways involving TP53 and cancer, we have exploited the zebrafish, a powerful vertebrate model system that is amenable to whole-genome forward-genetic analysis and synthetic-lethal screens. Zebrafish lines harboring missense mutations in the tp53 DNA-binding domain were identified by using a target-selected mutagenesis strategy. Homozygous mutant fish from two of these lines were viable and exhibited mutations similar to those found in human cancers (tp53(N168K) and tp53(M214K)). Although homozygous tp53(N168K) mutants were temperature-sensitive and suppressed radiation-induced apoptosis only at 37 degrees C, cells in the tp53(M214K) embryos failed to undergo apoptosis in response to gamma radiation at both 28 and 37 degrees C. Unlike wild-type control embryos, irradiated tp53(M214K) embryos also failed to up-regulate p21 and did not arrest at the G(1)/S checkpoint. Beginning at 8.5 months of age, 28% of tp53(M214K) mutant fish developed malignant peripheral nerve sheath tumors. In addition to providing a model for studying the molecular pathogenic pathways of malignant peripheral nerve sheath tumors, these mutant zebrafish lines provide a unique platform for modifier screens to identify genetic mutations or small molecules that affect tp53-related pathways, including apoptosis, cell-cycle delay, and tumor suppression.

Alleles↗
PubMed2005

Intraabdominal cystic lymphangiomas obscured by marked superimposed reactive changes: clinicopathological analysis of a series.

Cystic (or cavernous) lymphangiomas are uncommon tumors that most often occur in the head and neck, axilla, or groin of young children but are detected occasionally in adulthood at various other anatomic sites. When arising in the abdomen, cystic lymphangiomas may present with acute abdominal pain. We have encountered examples of mesenteric and retroperitoneal cystic lymphangiomas associated with such marked superimposed reactive and inflammatory changes that their lymphatic nature is obscured, a situation that is not widely recognized. To further characterize these lesions, 7 abdominal lymphangiomas associated with florid reactive changes were retrieved from the authors' consultation files. There were 5 female patients and 2 male patients (median age, 42 years; range, 1 month to 51 years). Five cases presented in adulthood. Tumor size ranged from 8 to 20 cm (median, 15 cm). Three tumors arose in the mesentery of the small intestine and 4 arose in the retroperitoneum (one of which also involved the posterior mediastinum). Three patients presented with a short history of abdominal pain. Radiological studies revealed large cystic or solid masses; clinical differential diagnoses included sarcoma (2 cases), enteric duplication cyst (2 cases), and cystic tumor not otherwise specified. Grossly, the tumors were generally multiloculated cystic masses associated with areas of fat necrosis and hemorrhage. The cysts often contained thick, gelatinous, or milky fluid. Histologically, all cases showed extensive areas of granulation tissue, most also including a floridly cellular reactive myofibroblastic proliferation, obscuring the lymphatic nature of the lesion. Two cases contained extensive areas of xanthogranulomatous inflammation. In foci where the underlying lesion could be discerned, the tumors were composed of cystically dilated lymphatic spaces, some of which were partially invested by a layer of smooth muscle and were associated with occasional lymphoid aggregates. The lymphatic spaces contained either clear fluid or large numbers of foamy macrophages. The lymphatic endothelial cells lining the cystic spaces were generally attenuated with no cytological atypia. One case showed features of a complex vascular malformation with a predominant component of cavernous lymphangioma. By immunohistochemistry, in all cases, the endothelial cells lining the dilated lymphatic spaces were positive for CD31 and D2-40, 4 of 7 were positive for CD34, and all were negative for keratin. Clinical follow-up information was available for 4 patients (median, 26 months; range, 22-36 months): 3 patients had no evidence of recurrence and 1 patient was asymptomatic with radiographic evidence of minimal persistent disease. In summary, some intraabdominal lymphangiomas have a tendency to induce marked reactive and inflammatory changes in the surrounding tissues, often obscuring their nature and occasionally leading to the clinical impression of a malignant tumor. Awareness of this unusual occurrence will lead to the correct diagnosis.

Abdominal Neoplasms↗
PubMed2005

Clinicopathologic and molecular genetic characterization of low-grade fibromyxoid sarcoma, and cloning of a novel FUS/CREB3L1 fusion gene.

Low-grade fibromyxoid sarcoma (LGFMS) is an indolent, late-metastasizing malignant soft-tissue tumor that is often mistaken for either more benign or more malignant tumor types. Cytogenetic analyses have identified a recurrent balanced translocation t(7;16) (q32-34;p11), later shown by molecular genetic approaches to result in a FUS/CREB3L2 fusion gene. Whereas preliminary studies suggest that this gene rearrangement is specific for LGFMS, its incidence in this tumor type and the possible existence of variant fusion genes have not yet been addressed. For this purpose, a series of potential LGFMS were obtained from nine different soft-tissue tumor centres and subjected to molecular analysis as well as careful histopathologic review. Reverse transcriptase-polymerase chain reaction analysis disclosed a FUS/CREB3L2 fusion transcript in 22 of the 23 (96%) cases that remained classified as LGFMS after the histologic re-evaluation and from which RNA of sufficient quality could be extracted, whereas none of the cases that were classified as other tumor types was fusion-positive. In one of the tumors with typical LGFMS appearance, we found that FUS was fused to the CREB3L1 gene instead of CREB3L2. The proteins encoded by these genes both belong to the same basic leucine-zipper family of transcription factors, and display extensive sequence homology in their DNA-binding domains. Thus, it is expected that the novel FUS/CREB3L1 chimera will have a similar impact at the cellular level as the much more common FUS/CREB3L2 fusion protein. Taken together, the results indicate that virtually all LGFMS are characterized by a chimeric FUS/CREB3L2 gene, and that rare cases may display a variant FUS/CREB3L1 fusion.

Adolescent↗
PubMed2005

Intestinal perineuriomas: clinicopathologic definition of a new anatomic subset in a series of 10 cases.

Benign peripheral nerve sheath tumors are uncommon in the gastrointestinal tract, and perineuriomas have not previously been reported to occur at this anatomic location. In this study, we analyzed the clinicopathologic and immunohistochemical features of 10 perineuriomas arising in the intestine. Eight patients were female and 2 male (median age, 51 years; range, 35-72 years). Eight of the lesions were intramucosal perineuriomas presenting as small sessile polyps detected during colonoscopy; 6 of these 8 patients were asymptomatic and undergoing colorectal cancer screening. The remaining 2 cases were submucosal masses, one each located in the colon and jejunum. Of the mucosal polyps, six were located in the rectosigmoid or sigmoid colon and one each was detected in the descending colon and transverse colon. The polyps ranged from 0.2 to 0.6 cm (median, 0.4 cm) in greatest dimension. The colonic and jejunal masses measured 3 cm and 4.5 cm, respectively. Histologically, the intramucosal perineuriomas were composed of uniform bland spindle cells having ovoid to elongated nuclei and pale indistinct cytoplasm, with no cytologic atypia, pleomorphism, or mitotic activity. The lesions had a fine collagenous stroma, demonstrated irregular borders with the adjacent lamina propria, and entrapped colonic crypts. Five cases exhibited hyperplastic changes in the adjacent or entrapped epithelium. The colonic submucosal tumor was microscopically well circumscribed, whereas the jejunal perineurioma showed focal infiltration through the muscularis propria into the subserosa. The stroma was collagenous in the colonic tumor and predominantly myxoid in the jejunal tumor. The spindle cells in the submucosal perineuriomas demonstrated tapered nuclei and elongated bipolar cytoplasmic processes. All tumors except one were positive for epithelial membrane antigen (EMA); 4 of 10 expressed claudin-1 and 2 of 10 expressed CD34. All tumors were negative for S-100 protein, glial fibrillary acidic protein, neurofilament protein, smooth muscle actin, desmin, caldesmon, KIT, and pan-keratin. Electron microscopy was performed on the tumor lacking EMA expression, revealing typical features of perineurioma, namely, spindle cells with long bipolar cytoplasmic processes and prominent pinocytotic vesicles, surrounded by discontinuous basal lamina. Clinical follow-up was available for 4 patients (median, 34 months; range, 8-53 months). No tumor recurred. In summary, perineuriomas may arise in the intestine, most often as intramucosal lesions detected as colorectal polyps with distinctive histologic features including entrapment of colonic crypts. Distinguishing perineuriomas from other spindle cell neoplasms of the gastrointestinal tract can be facilitated by immunostaining for EMA and claudin-1.

Adult↗
PubMed2005

Soft tissue perineurioma: clinicopathologic analysis of 81 cases including those with atypical histologic features.

Perineuriomas are uncommon benign peripheral nerve sheath tumors that include soft tissue, sclerosing, and intraneural variants. Fewer than 50 soft tissue perineuriomas have been reported to date, and the clinical significance of atypical histologic features is unknown. To characterize these tumors further, 81 soft tissue perineuriomas received between 1994 and 2003 were retrieved from the authors' consult files. Hematoxylin and eosin sections were reexamined, immunohistochemistry was performed, and clinical details were obtained from referring physicians. Forty-three patients were female and 38 male (mean age, 46 years; range, 10-79 years). Tumor size ranged from 0.3 to 20 cm (mean, 4.1 cm) in greatest dimension. Most patients presented with a painless mass. The tumors arose in a wide anatomic distribution: 36 lower limb, 19 upper limb, 15 trunk, 7 head and neck, 3 retroperitoneum, and 1 paratesticular. Forty-two tumors were situated primarily in subcutis, 25 in deep soft tissue, and 9 were limited to the dermis. Nearly all cases were grossly well circumscribed; 12 showed focal microscopically infiltrative margins. Most tumors had a storiform and focally whorled growth pattern; 17 exhibited fascicular areas. Thirty-eight tumors were hypocellular, 15 were markedly hypercellular, and 7 showed alternating zones of hypocellularity and hypercellularity. Stroma was usually collagenous but in 17 tumors was predominantly myxoid, and in 16 was mixed collagenous and myxoid. Mitoses ranged from 0 to 13 per 30 high power fields (mean, 1); 53 tumors had no mitoses. Based on worrisome cytologic or architectural features, 14 cases were classified as atypical perineuriomas: 12 contained scattered pleomorphic cells, 1 showed an abrupt transition from typical morphology to a markedly hypercellular, fascicular area with cytologic atypia, and 1 exhibited diffuse infiltration of skeletal muscle. All tumors were reactive for epithelial membrane antigen; 50 of 78 (64%) expressed CD34, 22 of 76 (29%) claudin-1, 16 of 77 (21%) smooth muscle actin, and 4 of 81 (5%) S-100 protein. All tumors were negative for glial fibrillary acidic protein, neurofilament protein, and desmin. Clinical follow-up was available for 43 patients (mean, 41 months; range, 6-146 months). Among tumors for which the status of surgical margins was known, 52% were widely excised, 31% were marginally excised, and 18% had positive margins. Only two tumors recurred locally (one of which was atypical): one recurred 10 years following primary excision; and one recurred twice, 5 and 9 years following excision. No tumor metastasized. Soft tissue perineuriomas behave in a benign fashion and rarely recur. Atypical histologic features (including scattered pleomorphic cells and infiltrative margins) seem to have no clinical significance and appear to be akin to those seen in ancient schwannoma and atypical (bizarre) neurofibroma.

Adolescent↗
PubMed2005

Primitive nonneural granular cell tumors of skin: clinicopathologic analysis of 13 cases.

A rare subset of distinctive cutaneous nonneural granular cell tumors was described by LeBoit et al in 1991 and termed "primitive polypoid granular-cell tumor." Herein, we report our experience with 13 similar, distinctive nonneural granular cell tumors. Affected patients included 7 males and 6 females ranging in age from 5 to 83 years (mean, 25 years; median, 16 years). These cutaneous lesions involved the back (5 cases), neck, shoulder, thigh (2 cases each), chin, and elbow (1 case each). Clinically described as smooth, nontender cutaneous nodules, the tumors ranged in size from 0.2 to 2.8 cm (median, 0.8 cm) and were present from months to years before excision. Mitoses numbered from 1 to 6 per mm (median, 2). Eight of the lesions were polypoid, based in the papillary dermis with extension to the superficial dermis and associated with an epithelial collarette. Five of the lesions were situated deeper in the reticular dermis with limited extension into the subcutis but clinically were also nodular. All the tumors were well circumscribed and composed of spindled to ovoid cells with abundant granular, eosinophilic cytoplasm and vesicular nuclei with small prominent nucleoli. Immunohistochemistry revealed reactivity only for NKI-C3 (11 of 12 cases), CD68 (7 of 11 cases), and NSE (5 of 10 cases); S-100 protein as well as other melanocytic, epithelial, and myoid markers were uniformly negative. All 13 of the lesions were locally excised and in the 8 cases with adequate follow-up ranging from 13 to 126 months (mean, 68 months; median, 41 months), none has recurred locally. However, one tumor (case no. 11) gave rise to a local lymph node metastasis 25 months after presentation, but the patient is currently disease-free 70 months after lymphadenectomy. These cutaneous granular tumors do not appear to be neural or Schwannian in nature, but their precise line of differentiation is unknown.

Adolescent↗
PubMed2005

Radiation-associated cutaneous atypical vascular lesions and angiosarcoma: clinicopathologic analysis of 42 cases.

Cutaneous angiosarcoma is a rare but well-recognized complication after radiation therapy. Atypical post-radiation vascular lesions (AVLs) with a benign course have been described recently, but few cases with limited follow-up have been studied so far. A total of 42 cases diagnosed as either radiation-associated cutaneous vascular lesions or angiosarcoma were retrieved from departmental and consultation files from 1995 to 2003. Hematoxylin and eosin-stained sections and clinical as well as follow-up data were evaluated. All patients were female with a median age of 59 years (range, 36-90 years). Presentation ranged from small erythematous/violaceous papules or nodules to large plaques with discoloration located on the chest wall (35), abdomen (2), shoulder, groin, flank, axilla, and lower leg (1 each). Reasons for radiation included breast carcinoma (35 cases) and a variety of other lesions (mainly malignant disease). Size range was 0.1 to 20 cm. Angiosarcomas presented as larger lesions (median, 7.5 cm) compared with AVLs (median, 0.5 cm). The time interval from radiation was significantly shorter for the development of AVL (median, 3.5 years) compared with cutaneous angiosarcoma (median, 6 years). Histologic evaluation revealed 26 lesions meeting criteria for angiosarcoma, ranging from morphologically low-grade to high-grade; 16 cases were classified as AVLs. These were fairly well-circumscribed lesions confined within superficial to mid dermis and composed of complex anastomosing and focally dilated vascular spaces. Some showed prominent hyperchromatic endothelial cells, while others were characterized by areas with a dissecting growth pattern within dermal collagen. Endothelial multilayering was absent. Clinical follow-up, available for 36 patients (range, 2-84 months; median, 17 months), revealed 4 patients who died of disease, 4 patients had systemic metastasis, and 12 patients with local recurrence. All patients with systemic relapse had an initial diagnosis of angiosarcoma. One patient with an AVL had a recurrence at the same site, 3 patients developed additional new lesions, and 1 patient developed multiple small papules on the chest wall, which progressed from an AVL to angiosarcoma. This study outlines the morphologic spectrum of radiation-associated cutaneous AVLs. No adverse outcome has been observed so far in this more benign subset of cases, but longer-term follow-up is necessary.

Adult↗