Abdominal plaque in a 10-day-old boy.
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Abdomen↗
Biomedical subjects
Steven D Billings
Publications and source records attributed to Steven D Billings.
Fungating forehead plaque: angiosarcoma.
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Aged↗
Spindle cell lipoma of the oral cavity.
Spindle cell lipoma is typically seen in the neck/trunk region of middle-aged and older men. Rare cases of oral spindle cell lipoma have been reported. An entity described as myxoid lipoma of the oral cavity has rarely been reported but appears to be more properly classified as spindle cell lipoma. We describe the largest series yet of oral spindle cell lipoma involving the tongue (4), buccal mucosa (1), floor of mouth (1), and lip (1). The patients (3M; 4F) ranged from 31 to 88 years old. All presented with mass lesions. All were circumscribed and composed of mature adipocytes admixed with bland spindled cells. In two cases the adipocytes appeared atrophic, imparting a pseudo-lipoblastic appearance. No true lipoblasts were seen and none had the characteristic vasculature of a myxoid liposarcoma or the characteristic hyperchromatic cells of well-differentiated liposarcoma. The stromal background of all cases contained characteristic wiry collagen and myxoid ground substance. The myxoid ground substance was prominent in four cases. Immunohistochemical stains for CD34 highlighted the bland spindle cells in all cases. The combination of the histologic features and the immunoreactivity for CD34 confirmed the diagnosis. Spindle cell lipoma should be considered in the differential diagnosis of oral cavity mesenchymal tumors.
Adult↗
Langerhans cell histiocytosis associated with myelodysplastic syndrome in adults.
BACKGROUND: Myelodysplastic syndrome (MDS) is a group of bone marrow disorders associated with dyplasia of myeloid elements that may have cutaneous manifestations including infections, vasculitis, Sweet's syndrome, pyoderma gangrenosum, erythema elevatum diutinum, and leukemia cutis. These cutaneous manifestations are attributed to the underlying bone marrow defect. Langerhans cell histiocytosis (LCH) is primarily a pediatric disease, and rarely LCH has been described in association with pediatric MDS. We are aware of only a single case report of LCH associated with MDS in an adult. METHODS: We report two new cases of LCH in elderly patients with underlying MDS. The specimens were examined by routine microscopy as well as immunohistochemical stains for S100 protein and CD1a. RESULTS: Both patients were elderly men with established diagnoses of MDS. One presented with a solitary pruritic papule while the other had a 2-year history of erythematous papules involving the trunk and extremities. Histologic examination revealed intraepidermal and dermal collections of mononuclear cells with reniform nuclei. The cells were strongly positive for S100 and CD1a, confirming their identity as Langerhans cells. CONCLUSION: Cutaneous LCH may be associated with underlying MDS in adults and should be considered in the differential diagnosis of cutaneous eruptions in patients with MDS.
Aged↗
Staphylococcal lipoteichoic acid inhibits delayed-type hypersensitivity reactions via the platelet-activating factor receptor.
Staphylococcus aureus infections are known triggers for skin inflammation and can modulate immune responses. The present studies used model systems consisting of platelet-activating factor receptor-positive and -negative (PAF-R-positive and -negative) cells and PAF-R-deficient mice to demonstrate that staphylococcal lipoteichoic acid (LTA), a constituent of Gram-positive bacteria cell walls, acts as a PAF-R agonist. We show that LTA stimulates an immediate intracellular Ca2+ flux only in PAF-R-positive cells. Intradermal injections of LTA and the PAF-R agonist 1-hexadecyl-2-N-methylcarbamoyl glycerophosphocholine (CPAF) induced cutaneous inflammation in wild-type but not PAF-R-deficient mice. Systemic exposure to LTA or CPAF inhibited delayed-type hypersensitivity (DTH) reactions to the chemical dinitrofluorobenzene only in PAF-R-expressing mice. The inhibition of DTH reactions was abrogated by the addition of neutralizing antibodies to IL-10. Finally, we measured levels of LTA that were adequate to stimulate PAF-R in vitro on the skin of subjects with infected atopic dermatitis. Based on these studies, we propose that LTA exerts immunomodulatory effects via the PAF-R through production of the Th2 cytokine IL-10. These findings show a novel mechanism by which staphylococcal infections can inhibit Th1 reactions and thus worsen Th2 skin diseases, such as atopic dermatitis.
Animals↗
Ultraviolet B radiation generates platelet-activating factor-like phospholipids underlying cutaneous damage.
Ultraviolet B light (UVB) causes cutaneous inflammation and cell death, but the agents responsible are not defined. These studies examined the role of the platelet-activating factor (PAF) signaling system in UVB-mediated effects. Expression of the PAF receptor in the PAF receptor-negative epidermoid cell line KB augmented apoptosis in response to UVB irradiation. Overexpression of the PAF receptor in primary human keratinocytes also enhanced UVB-mediated apoptosis in vitro, and it enhanced apoptosis in an in vivo model of human keratinocytes grafted onto severe combined immune-deficient (SCID) mice. To define the mechanism by which UVB activates the PAF receptor, we used mass spectrometry to demonstrate significant amounts of the C4 PAF analogs 1-alkyl-2-(butanoyl and butenoyl)-sn-glycero-3-phosphocholine, as well as native PAF in an epidermal cell line after UVB irradiation. Supplementing the cells with the precursor phospholipid 1-hexadecyl-2-arachidonoyl-sn-glycero-3-phosphocholine (HAPC) increased the amount of C4 PAF analogs recovered after UVB exposure. We irradiated HAPC directly and found, even in the absence of a photosensitizer, fragmentation to C4-PAF receptor ligands. We conclude UVB photo-oxidizes cellular phospholipids, creating PAF analogs that stimulate the PAF receptor to induce further PAF synthesis and apoptosis. PAF signaling may participate in the cutaneous inflammation that occurs during photo-aggravated dermatoses.
Animals↗
Superficial low-grade fibromyxoid sarcoma (Evans tumor): a clinicopathologic analysis of 19 cases with a unique observation in the pediatric population.
Low-grade fibromyxoid sarcoma (LGFMS), usually a deeply situated mass in adults, is uncommon in superficial soft tissue and in children. Nineteen superficial LGFMS from our files were studied for clinicopathologic features, the latter including tumor size, growth pattern, cellularity, collagen rosettes, vascularity, nuclear atypia, mitotic rate, necrosis, and immunophenotype. The patients included 12 males and 7 females who ranged in age from 2 to 70 years (mean, 29 years). There were 7 children. Tumor locations included the lower extremity (8), buttock (3), trunk (3), vulva/inguinal region (2), upper extremity (2), and unspecified subcutis (1). Clinical and histologic submitting diagnoses were mainly benign except for 3 cases, submitted as low-grade sarcoma, with only one as superficial LGFMS. The mean tumor size was 4.2 cm (range, 1.6-18 cm). Of 15 with evaluable resections, 5 had focal ink on tumor and 2 of these had known negative wider reexcisions. The tumors were relatively well circumscribed with low to moderate cellularity. The tumors alternated from myxoid zones with prominent curvilinear vasculature to collagenous fascicular zones. Collagen rosettes with peripheral round epithelioid cells and focal ischemic necrosis were present in 6 cases each. Mitotic rate was low (mean 1.6/50 HPF). Tumor cells were positive for vimentin and some were focally positive for actins, CD68, and EMA. CD34, keratins, and S-100 protein were negative. Follow-up (mean, 44 months; range, 10-84 months) on 16 patients demonstrated 14 with no evidence for disease, 2 with local recurrences at 5 and 16 months, but no metastases. Superficial LGFMS is more common than previously recognized and may affect children at a higher rate (7 of 19, 37%) than that for deep LGFMS. The prognosis is good and appears to be better than that for deep LGFMS.
Adolescent↗
Immunolocalization of low-affinity prostaglandin E receptors, EP and EP, in adult human epidermis.
Four prostaglandin (PG)E(2) receptors have been described, termed E-series prostaglandin receptors (EP(1)-EP(4)), that can be further subclassified as low-affinity (EP(1) and EP(2)) or high-affinity (EP(3) and EP(4)) receptors. Activation of the low-affinity PGE(2) receptors is likely to be important in mediating the actions of the high levels of PGE(2) found in various pathologic processes. The pattern of expression of these receptors in epidermis, however, is unknown. We therefore examined the immunolocalization of the EP(1) and EP(2) receptors in human epidermis. The EP(1) and EP(2) receptors demonstrated both plasma membrane and perinuclear or nuclear staining within the basal and spinous layers. Within the granular layer, both receptors were expressed in the cytoplasm with a grainy or granular appearance. The major differences were that the EP(2) receptor demonstrated a zone of decreased to absent plasma membrane staining in the superficial spinous layer and only scattered cellular staining within the granular layer. In contrast, the EP(1) receptor was prominently expressed throughout the stratum granulosum and the plasma membrane staining pattern was seen throughout the spinous layer. In cultured primary human keratinocytes, we also verified the presence of functional EP(1) receptor coupled to intracellular calcium mobilization and EP(2) receptor coupled to cAMP production.
Adenylyl Cyclases↗
Gene correction reduces cutaneous inflammation and granuloma formation in murine X-linked chronic granulomatous disease.
Our laboratory previously demonstrated that X-linked chronic granulomatous disease (X-CGD) mice develop exaggerated inflammatory responses and form granulomas following intradermal challenge with sterile Aspergillus fumigatus (AF) hyphae. In this study, we examined the efficacy of retroviral-mediated gene transfer (RMGT) into X-CGD bone marrow stem cells in preventing this abnormal inflammatory response. Sterile AF or saline was injected subcutaneously into the ears of wild-type, female X-CGD carrier, X-CGD, or X-CGD mice chimeric for varying numbers of either wild-type or RMGT-corrected neutrophils. Intradermal AF induced marked inflammation at both 3 and 30 d in the X-CGD mice, but not in the carriers or the wild-type mice. Similar to wild-type mice, chimeric X-CGD mice with >20% oxidase-positive neutrophils displayed a minimal and self-limited inflammatory response. Inflammation in chimeric (both wild-type and RMGT-corrected) mice with <15% oxidase-positive neutrophils was also improved compared to X-CGD mice, although still abnormal. This is the first evidence that partial correction of NADPH oxidase activity by gene therapy is likely to be beneficial in reducing or preventing the chronic inflammatory complications of CGD patients if sufficient numbers of RMGT-corrected neutrophils are obtained.
Animals↗
Trafficking pathways and characterization of CD4 and CD8 cells recruited to the skin of humans experimentally infected with Haemophilus ducreyi.
T-cell homing to infected skin is not well studied in humans. We examined sites experimentally infected with Haemophilus ducreyi by immunohistochemistry and flow cytometry for expression of receptors and ligands involved in cutaneous T-cell homing and determined the phenotypes of the T cells that trafficked to skin. Endothelial cells expressed E-selectin in infected but not uninfected skin, while peripheral node addressin (PNAd) was minimally expressed in all samples. CC chemokine ligand 27 (CCL27) was expressed in the epidermis and endothelium of both infected and uninfected skin. Interestingly, CCL21, a chemokine thought to be associated principally with T-cell trafficking in the lymphatic compartment, was highly expressed on the endothelium of infected skin. Few naive cells were present in experimental lesions, emphasizing the combined role of PNAd and CCL21 in trafficking of this subset. Memory cells (CD45RA-) dominated both CD4 and CD8 T-cell populations at the site of infection. Effector memory (CD45RA- CD27-) CD4+ and CD8+ T cells were enriched in lesions. Although the CC chemokine receptor 7-positive (CCR7+) population of both central memory (CD45RA- CD27+) and effector memory cells was not enriched in the skin compared to peripheral blood, CCR7+ cells were not precluded from entering infected skin. Taken together with our previous work (D. Soler, T. L. Humphreys, S. M. Spinola, and J. J. Campbell, Blood 101:1677-1683, 2003), these studies led us to propose a model of memory T-cell trafficking to skin in response to experimental H. ducreyi infection.
Adult↗
Aberrant expression of tight junction-related proteins ZO-1, claudin-1 and occludin in synovial sarcoma: an immunohistochemical study with ultrastructural correlation.
Synovial sarcoma demonstrates epithelial differentiation, either by light microscopy (biphasic synovial sarcoma) or by immunohistochemical/ultrastructural methods only (monophasic) and poorly differentiated synovial sarcoma. Although the glands of synovial sarcoma are known to have tight junction-like structures, far less is known about junction formation in the spindled component of synovial sarcomas. Additionally, it is unknown whether the tight junctions of synovial sarcoma are normally constituted. The tight junction is a multiprotein complex consisting of numerous proteins that include ZO-1, claudin-1 and occludin. A total of 35 cases of synovial sarcoma (13 biphasic, 14 monophasic and eight poorly differentiated) were immunostained for ZO-1, claudin-1 and occludin using commercially available antibodies, heat-induced epitope retrieval and standard avidin-biotin technique. When available, corresponding electron micrographs were reviewed. For five cases, the presence of either an SYT-SSX1 (three cases) or SYT-SSX2 (two cases) gene fusion was known. Positive cases showed particulate membrane staining. The glands of biphasic synovial sarcomas expressed ZO-1 (13/13), claudin-1 (12/13) and occludin (11/13) in a manner identical to normal glandular epithelia, at the apical portion of the lateral membrane. The spindle cells of biphasic synovial sarcomas showed abnormal circumferential membranous expression of ZO-1 (12/13), claudin-1 (6/13) and occludin (3/13). Monophasic synovial sarcomas expressed ZO-1 in a circumferential pattern (13/14) but less often claudin-1 (4/14) or occludin (3/14). Poorly differentiated synovial sarcomas expressed ZO-1 (8/8) and claudin-1 (6/8) but only rarely occludin (2/8). By electron microscopy, recognizable tight junctions were seen only in glands. No correlation was seen between histologic subtype or fusion type and expression of tight junction proteins. We conclude that the glands of biphasic synovial sarcomas show well-organized, true epithelial tight junctions. In contrast, the spindled cells of all synovial sarcomas show significant abnormalities in the expression and localization of tight junction proteins, suggesting partial and/or aberrant epithelial differentiation.
Claudin-1↗
Cutaneous and subcutaneous fibrohistiocytic tumors of intermediate malignancy: an update.
The fibrohistiocytic tumors of intermediate malignancy are uncommon mesenchymal tumors, which typically occur in the skin and subcutis and which may pose significant problems for the dermatopathologist. This article reviews the clinical, histopathologic, and genetic features of dermatofibrosarcoma protuberans, giant cell fibroblastoma, angiomatoid (malignant) fibrous histiocytoma, plexiform fibrous histiocytoma, and soft tissue giant cell tumor (of low malignant potential). The differential diagnosis of these tumors with a variety of benign and fully malignant cutaneous soft tissue neoplasms is discussed.
DNA, Neoplasm↗
Most osteomalacia-associated mesenchymal tumors are a single histopathologic entity: an analysis of 32 cases and a comprehensive review of the literature.
Oncogenic osteomalacia (OO) is a rare paraneoplastic syndrome of osteomalacia due to phosphate wasting. The phosphaturic mesenchymal tumor (mixed connective tissue variant) (PMTMCT) is an extremely rare, distinctive tumor that is frequently associated with OO. Despite its association with OO, many PMTMCTs go unrecognized because they are erroneously diagnosed as other mesenchymal tumors. Expression of fibroblast growth factor-23 (FGF-23), a recently described protein putatively implicated in renal tubular phosphate loss, has been shown in a small number of mesenchymal tumors with known OO. The clinicopathological features of 32 mesenchymal tumors either with known OO (29) or with features suggestive of PMTMCT (3) were studied. Immunohistochemistry for cytokeratin, S-100, actin, desmin, CD34, and FGF-23 was performed. The patients (13 male, 19 female) ranged from 9 to 80 years in age (median 53 years). A long history of OO was common. The cases had been originally diagnosed as PMTMCT (15), hemangiopericytoma (HPC) (3), osteosarcoma (3), giant cell tumor (2), and other (9). The tumors occurred in a variety of soft tissue (21) and bone sites (11) and ranged from 1.7 to 14 cm. Twenty-four cases were classic PMTMCT with low cellularity, myxoid change, bland spindled cells, distinctive "grungy" calcified matrix, fat, HPC-like vessels, microcysts, hemorrhage, osteoclasts, and an incomplete rim of membranous ossification. Four of these benign-appearing PMTMCTs contained osteoid-like matrix. Three other PMTMCTs were hypercellular and cytologically atypical and were considered malignant. The 3 cases without known OO were histologically identical to the typical PMTMCT. Four cases did not resemble PMTMCT: 2 sinonasal HPC, 1 conventional HPC, and 1 sclerosing osteosarcoma. Three cases expressed actin; all other markers were negative. Expression of FGF-23 was seen in 17 of 21 cases by immunohistochemistry and in 2 of 2 cases by RT-PCR. Follow-up (25 cases, 6-348 months) indicated the following: 21 alive with no evidence of disease and with normal serum chemistry, 4 alive with disease (1 malignant PMTMCT with lung metastases). We conclude that most cases of mesenchymal tumor-associated OO, both in the present series and in the reported literature, are due to PMTMCT. Improved recognition of their histologic spectrum, including the presence of bone or osteoid-like matrix in otherwise typical cases and the existence of malignant forms, should allow distinction from other mesenchymal tumors. Recognition of PMTMCT is critical, as complete resection cures intractable OO. Immunohistochemistry and RT-PCR for FGF-23 confirm the role of this protein in PMTMCT-associated OO.
Adolescent↗
Cutaneous angiosarcoma following breast-conserving surgery and radiation: an analysis of 27 cases.
Iatrogenic angiosarcomas (AS), following treatment of breast carcinomas and attributed to chronic lymphedema, were first described by Stewart and Treves. With emphasis on breast-conserving therapy combined with adjuvant radiation, a recently recognized form of cutaneous postradiation angiosarcoma of the breast (CPRASB) has emerged. To more completely characterize CPRASB, 27 cases were analyzed. Histologic features studied included pattern of growth (vasoformative, sieve-like, or solid), nuclear grade, necrosis, and mitotic rate. Clinical and follow-up information was obtained. The patients received relatively standard radiation treatment. The median interval to diagnosis of CPRASB was 59 months; 5 occurred in less than 3 years. Lymphedema was largely absent, and when present was only mild in nature. CPRASB was frequently multifocal at presentation (13 of 27). All tumors had a vasoformative pattern of growth; the majority (16 of 27) had areas with a sieve-like pattern. The solid pattern was less frequent (7 of 27). The majority had high-grade nuclear features (16 grade 3, 8 grade 2, 3 grade1). The mean mitotic rate was 9/10 HPF. Necrosis was rare (2 of 27). All were treated with wide excision or mastectomy. Follow-up was available on 22 of 27 cases (median 44 months). Fourteen experienced local recurrence and 6 had multiple recurrences. Metastasis was documented in 9 of 22 patients and involved lungs (6), contralateral breast (3), skeleton (2), lymph nodes (1), and soft tissue (1). Eight patients died of disease, 2 died with disease, 4 were alive with disease, and 8 are alive without disease. The median interval to death was 33.5 months. All 4 patients with disease have documented metastasis. CPRASB differs from Stewart-Treves AS by its shorter latency period and lack of association with lymphedema.
Aged↗
Amphiregulin overexpression results in rapidly growing keratinocytic tumors: an in vivo xenograft model of keratoacanthoma.
Keratoacanthoma (KA) is a variant of cutaneous squamous cell carcinoma (SCC) known for rapid growth and potential for involution. Little is known about the basis for the rapid growth because of the dearth of model systems. We hypothesized that amphiregulin (AR), a keratinocyte autocrine growth factor, had a significant role. Using immunohistochemistry, we compared 21 KA, 6 conventional SCC, and 6 basal cell carcinomas (BCC) for AR expression. All KA were positive for AR, the majority with strong immunoreactivity. The SCC were positive (5 of 6), with generally weak staining; no BCC were positive. We developed laboratory model systems to study AR overexpression in keratinocytes and its role in the pathogenesis of KA. A retroviral transduction strategy was used to overexpress AR in the HaCaT keratinocyte-like cell line. The AR overexpressing cells (HaCaT-AR) displayed autonomous proliferation in serum-free media when compared with controls (HaCaT-NIE). To develop an in vivo model, xenografts of HaCaT-AR and HaCaT-NIE were grown on SCID mice. The HaCaT-NIE cells formed thin tumors resembling conventional SCC. The HaCaT-AR cells formed rapidly growing tumors with AR expression similar to KA. HaCaT-AR cells may represent a new system for the further evaluation of KA.
Amphiregulin↗
Identical allelic losses in mature teratoma and other histologic components of malignant mixed germ cell tumors of the testis.
Teratomas of the testis in post-pubertal patients are histologically diverse tumors that often coexist with other types of germ cell tumors. Using laser capture microdissection and loss of heterozygosity analysis, we investigated the clonality of mature teratoma and its relationship to other components of malignant mixed germ cell tumors to gain potential insight into the histogenetic relationship of teratoma with other germ cell tumor components. All 16 patients had mature teratoma as one component of their mixed germ cell tumors. The other histological subtypes included immature teratoma, seminoma, embryonal carcinoma, yolk sac tumor, and choriocarcinoma. Laser-assisted microdissection was performed on the formalin-fixed, paraffin-embedded tissue. Polymerase chain reaction was used to amplify genomic DNA at specific loci on chromosome 1p36.2 (D1S508), 2q22-32 (D2S156), 9p21-22 (D9S162), 11p13 (D11S903), 12q22-23 (D12S1051), and 18q21 (D18S46). Fourteen of 16 (88%) cases showed allelic loss in one or more components of the mixed germ cell tumors. Fourteen of 16 mature teratomas showed allelic loss in at least one of six microsatellite polymorphic markers analyzed. The frequency of allelic loss in mature teratoma was 50% (7 of 14) with D1S508, 33% (5 of 15) with D2S156, 58% (7 of 12) with D9S162, 43% (6 of 14) with D11S903, 20% (3 of 15) with D12S1051, and 33% (5 of 15) with D18S46. Completely concordant allelic loss patterns between mature teratoma and all of the other germ cell tumor components were seen in 10 of 14 tumors in which mature teratoma showed loss of heterozygosity. Our data support the common clonal origin of mature teratoma with other components of malignant mixed germ cell tumors of the testis.
Adolescent↗
Subungual pleomorphic fibroma.
BACKGROUND: Pleomorphic fibroma is a benign fibroblastic tumor characterized by pleomorphic, hyperchromatic cells or giant multinucleated cells embedded in a collagenous stroma. These cytologic features may lead to an incorrect diagnosis of malignancy. Most cases reported in the literature are located on trunk or extremities; the presentation as a subungual mass is rare. METHODS: We report an unusual case of a subungual pleomorphic fibroma in 66-year-old woman. Clinical information was obtained. Histologic examination and immunohistochemical studies were performed. RESULTS: A 66-year-old woman presented with a longstanding (40 years), subungual mass that deformed the nail of the left middle finger. Microscopic examination revealed a paucicellular tumor composed of hyperchromatic spindled, pleomorphic, floret-like giant cells embedded in haphazardly arranged collagen bundles in the dermis. No mitotic figures were seen. The tumor cells were vimentin-positive but did not stain with antibodies to S-100, cytokeratin, smooth muscle actin, factor XIIIa or CD34 negative. The diagnosis of a pleomorphic fibroma was made. Follow-up shows no evidence of tumor, 36 months after excision. CONCLUSION: Pleomorphic fibroma of the subungual region is an unusual cutaneous tumor with histologic features that may cause confusion with true sarcomas. This is only the second case reported of a subungual pleomorphic fibroma. Pleomorphic fibroma should be considered in the differential diagnosis of pleomorphic subungual tumors.
Aged↗
Epithelioid sarcoma-like hemangioendothelioma.
We are reporting seven histologically identical cases of a distinctive, low-grade vascular tumor that closely mimics an epithelioid sarcoma because of growth in solid sheets and nests, the eosinophilia of the rounded to slightly spindled neoplastic cells, and the diffuse, strong cytokeratin expression. Termed epithelioid sarcoma-like hemangioendothelioma, all were diagnosed by the submitting pathologist or another expert consultant as epithelioid sarcoma. Although none displayed architectural evidence of vascular differentiation in the form of multicellular vascular channels, some displayed subtle cytologic features of vascular differentiation and all displayed immunohistochemical evidence of endothelial differentiation. The patients (four male; three female) ranged in age from 17 to 54 years (median 23 years). Ranging in size from 1 to 3.5 cm, they occurred in the extremities (n = 5), scalp (n = 1), and chest wall (n = 1), both in deep (n = 3) and superficial (n = 3) soft tissue or both (n = 1). The tumors were characterized by sheets, ill-defined nodules, or fascicles of deeply eosinophilic cells set within a desmoplastic stroma. Multicellular vascular channel formation and/or hemorrhage were absent in all cases. In four cases intracytoplasmic vacuolization suggestive of intracytoplasmic vascular lumen formation was noted. The typical neoplastic cell was large and rounded in shape but modulated in areas to a spindled or multipolar shape. Mitotic activity was low (<5 mitotic figures/50 high power fields), nuclear pleomorphism was mild to moderate, and necrosis was absent. The tumors were positive for cytokeratin (6 of 6), vimentin (6 of 6), CD31 (5 of 6), FLI-1 (6 of 6), but negative for CD34 (0 of 6). Within a follow-up period of 3-72 months (median 39 months), two patients experienced a local recurrence and one patient regional soft tissue metastases, but no distant ones. Two patients presented with multifocal lesions suggestive of regional metastases. Currently, two patients are alive with disease and five are disease free. Epithelioid sarcoma-like hemangioendothelioma appears to be a largely unrecognized epithelioid vascular tumor with an indolent course. Despite its similar clinical and histologic features, it differs from epithelioid sarcoma by the presence of endothelial markers and the absence to date of distant metastases. Its distinction from other epithelioid vascular lesions is discussed. We think this tumor fits best into the family of "hemangioendothelioma" or vascular lesions of intermediate malignancy.
Adolescent↗