Biomedical subjects

Andreas Chott

Publications and source records attributed to Andreas Chott.

52 records · Page 3Linked to original sources

PubMed2003

High frequency of genetic aberrations in enteropathy-type T-cell lymphoma.

To define genetic aberrations playing a role in the development of enteropathy-type T-cell lymphoma (ETL), we examined 26 such tumors using a battery of 47 microsatellite markers. The most frequent aberration (seen in 40% of informative genotypes) was amplification of genomic material in region 9q34 encompassing c-abl and Notch-1 gene loci. Other frequent amplifications were detected in regions 5q33.3-34 and 7q31 (both in more than 30%). Multiple losses of heterozygosity were detected in 6p24, 7p21, 17q23-25, regions containing putative tumor suppressor genes, and in the p53 locus in 17p13.1. Analysis of the pattern of occurrence of these aberrations revealed existence of two ETL subgroups: one of them characterized by the 9q34 aberration and another smaller one showing allelic imbalances in 3q27. These two aberrations were mutually exclusive. Microsatellite instability (MSI) was detected in 69% of the examined lymphomas; the percentage of MSI-positive genotypes per tumor ranged from 2% to 12%. The spectrum of genetic alterations detected showed patterns dependent on morphology. Monomorpic ETLs displayed frequently biallelic TCR-gamma gene rearrangement (p = 0078, chi(2) test). They showed a different pattern and fewer allelic imbalances (no 3q27, 4q28, 13q14, fewer 5q21, or 5q33.3-34 aberrations) and a lower frequency of MSI than pleomorphic ETLs.

Adult↗

PubMed2003

Expression of platelet-derived growth factor-AA is associated with tumor progression in osteosarcoma.

Platelet-derived growth factors are secreted by mesenchymal cells. The homodimer platelet-derived growth factor-AA especially stimulates bone cells through interaction with the platelet-derived growth factor-alpha receptor homodimer. In this study we wanted to determine the expression of the receptor and its ligand in human osteosarcomas and to correlate the expression of platelet-derived growth factor-AA and -alpha receptor with clinicopathological parameters. Fifty-seven osteosarcomas were immunohistochemically analyzed for expression of platelet-derived growth factor-AA and platelet-derived growth factor-alpha receptor. Spearman's correlation coefficient revealed a strong correlation between the expression of platelet-derived growth factor-AA and platelet-derived growth factor-alpha receptor (r = 0.867). No differences were observed relative to gender, age, tumor stage, tumor location, and response to neoadjuvant chemotherapy between high or low platelet-derived growth factor-AA and platelet-derived growth factor-alpha receptor expression. High platelet-derived growth factor-AA expression correlated with tumor progression in univariate analysis (P = .0415; log-rank test), whereas platelet-derived growth factor-alpha receptor expression showed a trend toward a shorter disease-free survival, which failed to reach significance (P = .0627, log-rank test). In multivariate analysis, platelet-derived growth factor-AA expression remained a significant independent predictor of tumor progression (P = .021, Cox regression). Immunohistochemical analysis of platelet-derived growth factor-AA expression in osteosarcoma may be a useful marker of prognosis and may be considered as a possible target for novel therapeutic strategies.

Adolescent↗

PubMed2003

18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) for staging and follow-up of marginal zone B-cell lymphoma.

OBJECTIVE: According to recent reports, nodal marginal zone lymphoma (MZL) appears to be a distinctive lymphoma entity rather than a more advanced stage of extranodal MZL of mucosa-associated lymphoid tissue (MALT). We have therefore retrospectively evaluated all patients diagnosed with nodal or extranodal MZL who have been referred to our unit for imaging using (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET). PATIENTS AND METHODS: A total of 21 patients with a diagnosis of MZL upon referral for imaging with (18)F-FDG-PET were identified. Histological reassessment of biopsy specimens confirmed the diagnosis of extranodal MZL of MALT in 14 patients, while a diagnosis of nodal MZL was verified in 6 patients. Lymphoma cell proliferation was assessed immunohistochemically using a Ki-67 antibody. Whole-body (18)F-FDG-PET scans were performed on a GE advanced PET scanner 40 min after intravenous injection of 300-380 MBq (18)F-FDG. RESULTS: None of the patients with extranodal MZL showed focal tracer uptake within verified tumor sites. In contrast, 5 of the 6 patients with nodal MZL showed significant FDG uptake within the affected lymph nodes. These results did not simply reflect the different growth fractions of the two lymphoma entities since the proliferation indices of the two groups did not differ significantly. CONCLUSION: (18)F-FDG-PET visualizes nodal MZL in a high proportion of patients whereas FDG uptake is undetectable in extranodal MZL. Although limited by the small number of patients, this study suggests that imaging with (18)F-FDG-PET might play a potential role in the diagnostic workup of patients with nodal MZL involvement.

Aged↗

PubMed2003

Rituximab for treatment of advanced extranodal marginal zone B cell lymphoma of the mucosa-associated lymphoid tissue lymphoma.

BACKGROUND: Extranodal marginal zone B cell lymphoma of the mucosa-associated lymphoid tissue (MALT) is a relatively common type of lymphoma. Owing to its B cell lineage, it appears to be a potential target for treatment with the CD20 antibody rituximab. We present an analysis of our experience with rituximab for treatment of patients with advanced MALT lymphoma. PATIENTS AND METHODS: A retrospective analysis of patients with histologically verified MALT lymphoma undergoing treatment with rituximab was done. After reassessment of histological samples for the presence of MALT lymphoma, patients were evaluated as regards date of diagnosis, prior therapy for MALT lymphoma, sites of involvement upon treatment with rituximab, clinical response in terms of complete remission (CR), partial response (PR), stable disease (SD) and progressive disease as well as symptomatic response, duration of response and survival. RESULTS: A total of 9 patients with advanced MALT lymphoma undergoing therapy with single-agent rituximab were identified. All patients received treatment at a dose of 375 mg/m(2) once weekly x4. One patient each had relapsed after chemotherapy and radiation, respectively, while none of the other 7 patients had received prior cytotoxic treatment or radiation. Three patients achieved a CR, 2 patients had PR for 6 and 14 months, while the remaining patients had SD between 8 and 18+ months. One patient died of progressive disease in spite of the initiation of chemotherapy and 1 patient succumbed to a cardiovascular event while having been in ongoing PR for 11 months. The other 7 patients are currently alive with disease 10-27 months after initiation of therapy. Follow-up biopsies for histological assessment were available in 5 patients with gastric lymphoma. In 1 patient with SD, however, persistence of CD20-positive cells within lymphoepithelial lesions was noted in spite of almost complete depletion of B lymphocytes from the normal gastric mucosa, suggesting either recirculation of MALT lymphoma cells to these lesions or defining lymphoepithelial lesions as a sanctuary site from rituximab penetration. CONCLUSION: Rituximab had only moderate activity in terms of inducing objective responses in our unselected and heterogeneous cohort of patients with disseminated MALT lymphoma. Long-term disease stabilization, however, along with a symptomatic benefit was seen in all patients. Our data nevertheless indicate that rituximab might not optimally penetrate into the gastric mucosa in all patients.

Antibodies, Monoclonal↗

PubMed2003

Immunohistochemical detection of VEGF in the bone marrow of patients with acute myeloid leukemia. Correlation between VEGF expression and the FAB category.

We studied vascular endothelial growth factor (VEGF) expression in bone marrow sections obtained from 3 healthy donors and 41 patients with acute myeloid leukemia (AML) of various French-American-British (FAB) subtypes by immunohistochemical analysis using an anti-VEGF antibody. In normal bone marrow, the anti-VEGF antibody reacted with myeloid progenitor cells and megakaryocytes but not with erythroid cells or mature granulocytic cells. High levels of VEGF were found in the bone marrow in patients with AML-M1, -M2, -M3, -M4, -M4Eo, and -M5. In these leukemias, the vast majority of myeloblasts (> 90%) expressed VEGF. By contrast, in AML-M0, the percentage of VEGF-positive blasts was lower in most cases (median, 42%), and if at all detectable, these blast cells contained only trace amounts of VEGF. In AML-M3 and -M4Eo, maturing granulocytes failed to express VEGF similar to granulocytes in normal bone marrow. In AML-M6, myeloblasts exhibited VEGF, whereas erythroid cells did not. In AML-M7, blast cells and megakaryocytes were identified as major sources of VEGF. In summary, VEGF expression in the bone marrow is restricted to certain stages of differentiation and maturation of myeloid cells and correlates with the FAB category.

Adolescent↗

PubMed2003

Low p27Kip1 expression is an independent adverse prognostic factor in patients with multiple myeloma.

PURPOSE: To determine the clinical relevance of p27(Kip1) in multiple myeloma (MM), we examined the relationship between p27(Kip1) expression at diagnosis and clinical as well as laboratory parameters, including response to chemotherapy and overall survival in 74 previously untreated patients with MM. EXPERIMENTAL DESIGN: Expression of p27(Kip1) was assessed by immunohistochemistry on formalin-fixed, paraffin-embedded bone marrow biopsies. p27(Kip1) expression was classified as low (</=5% p27(Kip1)-positive myeloma cells) or high (>5% p27(Kip1)-positive myeloma cells). RESULTS: Low p27(Kip1) expression was observed in 23 (31%) patients. The response rate to standard dose chemotherapy (including vincristine, doxorubicin, and dexamethasone induction before high-dose chemotherapy) was 70%, with no significant difference between patients with low or high p27(Kip1) expression (83 versus 65%; P = 0.1). Kaplan-Meier analysis of all 74 patients revealed that patients with low p27(Kip1) expression had a significantly shorter overall survival (median, 3.7 years versus 4.7 years; P = 0.03) than those with high p27(Kip1) expression. Patients with high p27(Kip1) expression receiving high-dose chemotherapy experienced prolonged overall survival as compared with those with low p27(Kip1) expression (median not yet reached versus 2.9 years; P = 0.008). By multivariate Cox regression analyses, low p27(Kip1)(P = 0.03), deletion of chromosome 13q14 (P = 0.02), and beta(2)-microglobulin (P = 0.01) were identified as independent adverse prognostic factors for overall survival. According to the number of independent unfavorable prognostic factors present in each patient, low-risk, intermediate-risk, and high-risk patients with different overall survival times were defined (median overall survival, 6.3 versus 4.2 versus 1.8 years; P < 0.001). CONCLUSIONS: Low p27(Kip1) expression is an independent adverse prognostic factor in patients with MM. The proposed risk score might be useful for risk-adapted treatment in the future.

Adult↗

PubMed2002

High incidence of t(11;18)(q21;q21) in Helicobacter pylori-negative gastric MALT lymphoma.

In approximately 5% to 10% of gastric mucosa-associated lymphoid tissue (MALT) lymphomas, evidence of Helicobacter pylori infection is absent, and their pathogenesis is poorly understood. We reviewed the clinical data and histology, and we examined t(11;18)(q21;q21) and BCL10 expression pattern in 17 such cases. In each case, the absence of H pylori was confirmed by negative serology and histology/immunohistochemistry. Five cases with stage I(E) disease were first treated with antibiotics, and none of them showed any endoscopic or histologic response. Review of the histology failed to identify any apparent difference between gastric MALT lymphomas with and without H pylori infection. Reverse transcription-polymerase chain reaction (RT-PCR) showed t(11;18)(q21;q21) in 9 (53%) of 17 cases, more frequent in lymphomas at stage II(E) or above (5 of 6) than those at stage I(E) (3 of 10). Two t(11;18)(q21;q21)-positive lymphomas were treated by partial gastrectomy and more than 16 years later showed lymphoma relapse in the gastric stump with dissemination to other mucosal sites, poorly responsive to therapy. BCL10 nuclear expression was observed in 7 of 8 t(11;18)(q21;q21)-positive cases and 4 of 7 t(11;18)(q21;q21)-negative cases, including one case suspicious for a BCL10-involved chromosomal translocation. Our results show that t(11;18)(q21;q21) occurs at a high frequency in H pylori-negative gastric MALT lymphomas. Translocation-positive gastric MALT lymphomas tend to be aggressive, and patients with such lymphomas might benefit from prompt treatment and close follow-up.

Adaptor Proteins, Signal Transducing↗

PubMed2002

T(14;18)(q32;q21) involving IGH and MALT1 is a frequent chromosomal aberration in MALT lymphoma.

T(11;18)(q21;q21) is the most common structural abnormality in extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) leading to the fusion of the apoptosis inhibitor-2 (API2) gene and the MALT lymphoma-associated translocation (MALT1) gene. In 2 patients with MALT lymphoma of the liver and skin, respectively, t(14;18)(q32;q21) was observed by cytogenetic analysis. Subsequent fluorescence in situ hybridization (FISH) studies disclosed that the immunoglobulin heavy-chain locus (IGH) and the MALT1 gene were rearranged by this translocation. In order to screen a large series of MALT lymphomas for this aberration, a 2-color interphase FISH assay was established. Among a total of 66 cases, t(14;18)(q32;q21) involving IGH and MALT1 was detected in MALT lymphomas of the liver (4 of 4), skin (3 of 11), ocular adnexa (3 of 8), and salivary gland (2 of 11), but did not occur in MALT lymphomas of the stomach (n = 10), intestine (n = 9), lung (n = 7), thyroid (n = 4), or breast (n = 2). In total, 12 of 66 (18%) MALT lymphomas harbored t(14;18)(q32;q21); 7 additional cases of splenic marginal zone lymphoma tested negative. All of the 12 MALT lymphomas featuring the t(14;18)(q32;q21) were negative for t(11;18)(q21;q21) by reverse transcriptase-polymerase chain reaction (RT-PCR). However, trisomy 3 and/or 18 was found in 4 of 12 cases, suggesting that the t(14;18)(q32;q21) does not occur as the sole genetic abnormality. This study identifies IGH as a new translocation partner of MALT1 in MALT lymphomas, which tend to arise frequently at sites other than the gastrointestinal tract and lung. In contrast to t(11;18)(q21;q21)(+) MALT lymphomas, those with t(14;18)(q32;q21) may harbor additional genetic abnormalities.

Caspases↗

PubMed2002

Treatment of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type with cladribine: a phase II study.

PURPOSE: As chemotherapy has not been extensively studied in patients with lymphoma of the mucosa-associated lymphoid tissue (MALT), we initiated a prospective study to evaluate the activity of the nucleoside analog cladribine (2-chlorodeoxyadenosine [2-CdA]) in this disease. PATIENTS AND METHODS: Patients with histologically verified MALT-type lymphoma were enrolled. 2-CdA was administered at a dose of 0.12 mg/kg body weight on 5 consecutive days, as a 2-hour infusion. Cycles were repeated every 4 weeks for a maximum of six cycles. RESULTS: Nineteen patients with gastric and seven patients with extragastric MALT lymphoma were enrolled. All patients were chemotherapy-naive, and two had been locally irradiated before systemic relapse of the lymphoma. A total of 102 cycles was administered to our patients (median number of cycles per patient, four). All 25 assessable patients responded to treatment: 21 patients (84%) achieved complete remission (CR) and four patients achieved partial remission. All patients (100%) with gastric presentation, but only three patients (43%) with extragastric presentation, achieved CR. Toxicities were moderate and mainly hematologic and required dose reduction and/or premature discontinuation of therapy in only three cases. Two patients died from vascular events, one shortly after the first cycle because of myocardial infarction and the other from stroke 3 months after the second course. Three patients relapsed after 13, 18, and 22 months and one patient showed progressive disease after 15 months. At present, 24 patients are alive at a median follow-up time of 32 months. CONCLUSION: Our data demonstrate that 2-CdA is highly effective in inducing CR in 84% of patients with MALT-type lymphoma.

Adult↗

PubMed2002

Expression of osteopontin and vascular endothelial growth factor in benign and malignant bone tumors.

Osteopontin (OPN), one of the major non-collagenous proteins of bone matrix, is together with vascular endothelial growth factor (VEGF) a potent angiogenic protein. In this study we determined the expression of OPN in benign and malignant bone tumors and investigated the prognostic influence of OPN expression on the outcome of osteosarcoma patients. Fifty-seven osteosarcomas and 11 osteoblastomas as well as 5 bone specimens with remodeling sites were immunohistochemically analyzed for expression of OPN and VEGF. OPN was not detected in osteoblasts of remodeling sites. Osteoblastoma osteoblasts as well as osteoclastlike giant cells and osteosarcoma mononuclear cells showed variable staining. In osteosarcomas OPN and VEGF expression correlated with each other (r=0.390, P=0.003, Spearman's test). Although osteosarcoma patients with high VEGF expression showed a trend towards shorter overall survival ( P=0.0841, log-rank test), OPN expression had no influence on patients overall or on disease-free survival. Our data indicate that expression of this protein might be upregulated in bone neoplasia. Although OPN expression correlates with VEGF expression in osteosarcomas, OPN expression does not provide predictive information about the outcome of osteosarcoma patients.

Adolescent↗

PubMed2002

Expression of the granzyme B inhibitor, protease inhibitor 9, by tumor cells in patients with non-Hodgkin and Hodgkin lymphoma: a novel protective mechanism for tumor cells to circumvent the immune system?

In tumor cells, the serine protease granzyme B is the primary mediator of apoptosis induced by cytotoxic T lymphocytes (CTLs)/natural killer (NK) cells. The human intracellular serpin proteinase inhibitor 9 (PI9) is the only known human protein able to inhibit the proteolytic activity of granzyme B. When present in the cytoplasm of T lymphocytes, PI9 is thought to protect CTLs against apoptosis induced by their own misdirected granzyme B. Based on the speculation that tumors may also express PI9 to escape CTL/NK cell surveillance, immunohistochemical studies on the expression of PI9 in various lymphomas were performed. Ninety-two cases of T-cell non-Hodgkin lymphoma (NHL), 75 cases of B-cell NHL, and 57 cases of Hodgkin lymphomas were stained with a PI9-specific monoclonal antibody. In T-cell NHL, highest PI9 expression was found in the extranodal T-cell NHL. In nearly 90% of enteropathy-type T-cell NHLs and 80% of NK/T-cell, nasal-type lymphomas, the majority of the tumor cells expressed PI9. In nodal T-anaplastic large cell lymphomas and peripheral T-cell lymphomas (not otherwise specified), PI9 expression occurred less frequently. In B-cell NHL, PI9 expression was associated with high-grade malignancy; 43% of diffuse large B-cell lymphomas showed PI9(+) tumor cells. Finally, PI9 expression was also found in 10% of Hodgkin lymphomas. This is the first report describing the expression of the granzyme B inhibitor PI9 in human neoplastic cells in vivo. Expression of this inhibitor is yet another mechanism used by tumor cells to escape their elimination by cytotoxic lymphocytes.

Antibodies, Monoclonal↗

PubMed2002

Increased angiogenesis in the bone marrow of patients with systemic mastocytosis.

Recent data suggest that angiogenesis in the bone marrow (BM) is augmented and associated with growth of neoplastic cells in various hematological malignancies. Systemic mastocytosis (SM) is a neoplasm affecting multilineage and mast cell (MC)-committed hemopoietic progenitors. In the present study, we have assessed the BM microvessel density (MVD) by CD34 immunohistochemistry in 21 patients with SM, 5 with cutaneous mastocytosis (no BM infiltrates), and 5 control cases (normal BM). The median BM MVD was significantly higher in SM compared to cutaneous mastocytosis or controls (P < 0.05). In addition, a significant correlation (r = 0.74) between the BM MVD and grade of MC infiltration (percent tryptase(+) BM infiltrates) was found in SM. Moreover, the MVD was higher in MC infiltrates compared to the nonaffected adjacent marrow (P < 0.05). Immunohistochemical staining revealed expression of vascular endothelial growth factor in MC infiltrates. The notion that SM is associated with increased BM angiogenesis and vascular endothelial growth factor expression may have implications for the biology of disease and development of new treatment strategies.

Antigens, CD34↗

PubMed2002

Chromosomal gains at 9q characterize enteropathy-type T-cell lymphoma.

Genetic alterations in enteropathy-type T-cell lymphoma (ETL) are unknown so far. In this series, 38 cases of ETL were analyzed by comparative genomic hybridization (CGH). CGH revealed chromosomal imbalances in 87% of cases analyzed, with recurrent gains of genetic material involving chromosomes 9q (in 58% of cases), 7q (24%), 5q (18%), and 1q (16%). Recurrent losses of genetic material occurred on chromosomes 8p and 13q (24% each), and 9p (18%). In this first systematic genetic study on ETL, chromosomal gains on 9q (minimal overlapping region 9q33-q34) were found to be highly characteristic of ETL. Fluorescence in situ hybridization analysis on four cases of ETL, using a probe for 9q34, indicated frequent and multiple gains of chromosomal material at 9q34 (up to nine signals per case). Among 16 patients with ETL who survived initial disease presentation, patients with more than three chromosomal gains or losses (n = 11) followed a worse clinical course than those with three or less imbalances (n = 5). The observation of similar genetic alterations in ETL and in primary gastric (n = 4) and colonic (n = 1) T-cell lymphoma, not otherwise specified, is suggestive of a genetic relationship of gastrointestinal T-cell lymphomas at either localization.

Adult↗

PubMed2002

Stem cell factor-induced bone marrow mast cell hyperplasia mimicking systemic mastocytosis (SM): histopathologic and morphologic evaluation with special reference to recently established SM-criteria.

Although systemic mastocytosis (SM) is a well-defined hematologic neoplasm, it is sometimes difficult to discriminate between SM and a reactive mast cell (MC) hyperplasia. We describe a patient with aplastic anemia who was treated with recombinant stem cell factor (SCF). In response to SCF, the patient showed transient hematologic improvement and developed a marked increase in MC as well as a transient increase in serum tryptase. Histologic and immunohistochemical examination revealed a huge increase in MC in the bone marrow with focal infiltrates similar to SM. However, most of the SM-criteria were not met: First, MC showed normal cytomorphological characteristics without significant atypias (no cytoplasmic extensions, no oval nuclei, no hypogranulated cytoplasm). Furthermore, bone marrow MC were CD2- and CD25-negative and did not exhibit the C-KIT 2468 A-->T mutation (Asp-816-Val). After discontinuation of SCF the MC hyperplasia resolved confirming its reactive nature. Based on our case and similar cases mimicking mastocytosis, it seems of importance to apply recently established SM criteria in order to discriminate between reactive MC hyperplasia and true mastocytosis with certainty.

Anemia, Aplastic↗

PubMed2002

Comparison of spiral-computed tomography with water-filling of the stomach and endosonography for gastric lymphoma of mucosa-associated lymphoid tissue-type.

BACKGROUND: Endosonography has been reported as the method of choice for local staging of patients with gastric lymphoma of mucosa-associated lymphoid tissue (MALT)-type. As endosonography is still restricted to specialized centers, we have investigated the use of spiral computed tomography of the abdomen with water-filling of the stomach (hydro-spiral CT) for enhanced contrast in patients with gastric lymphoma. PATIENTS AND METHODS: Patients with a histological verified diagnosis of gastric lymphoma of MALT-type were included in this prospective series. All patients underwent routine staging procedures including endosonography of the upper GI-tract carried out by a single individual. In addition, patients were subjected to hydro-spiral CT either before or after endosonography within a maximal time span of 4 weeks. Results of hydro-spiral CT were compared to those of the endosonographic evaluation and histological work-up of biopsy specimens. RESULTS: A total of 14 patients with primary gastric lymphoma of MALT-type (3 with a high-grade component) were studied prospectively. All patients underwent hydro-spiral CT before initiation of treatment, and 2 patients were also studied following chemotherapy. In the pretherapeutic setting, hydro-spiral CT identified gastric lymphoma in 8 patients, while a false negative result was seen in 6 patients. In addition, the localization of the lymphoma within the stomach was divergent between CT and endosonography in 1 patient. In the 2 patients who were also studied after therapy, CT showed unchanged thickening of the stomach wall in spite of normalization in the endosonographic assessment as well as the histologic evaluation. CONCLUSION: Our results demonstrate the superiority of endosonography over hydro-spiral CT for the staging and follow-up of patients with gastric lymphoma, who should therefore be managed at centers where endosonography is available.

Adult↗

PubMedDate not supplied

The spectrum of cutaneous lymphomas in patients less than 20 years of age.

Cutaneous lymphomas are rare in young patients and are mostly represented by mycosis fungoides and its variants and CD30+ lymphoproliferative disorders (lymphomatoid papulosis [LYP] and anaplastic large T-cell lymphoma). We report our observations in a series of 69 patients less than 20 years of age who presented either with primary cutaneous lymphoma (n = 62) or with secondary manifestations of extracutaneous disease (n = 7). Clinicopathologic features permitted classification of the cases into the following diagnostic categories: mycosis fungoides (n = 24, all primary cutaneous), anaplastic large T-cell lymphoma (n = 13, all primary cutaneous), LYP (n = 11, all primary cutaneous), subcutaneous "panniculitis-like" T-cell lymphoma (n = 1, primary cutaneous), small-medium pleomorphic T-cell lymphoma (n = 2, all primary cutaneous), natural killer (NK)/T-cell lymphoma, nasal-type (n = 1, secondary cutaneous), follicle center cell lymphoma (n = 1, primary cutaneous), marginal zone B-cell lymphoma (n = 7, all primary cutaneous), B-lymphoblastic lymphomas (n = 6, 3 primary and 3 secondary cutaneous), specific cutaneous manifestations of Hodgkin disease (n = 1, secondary cutaneous), and acute myeloid leukemia (n = 2, both secondary cutaneous). Cutaneous lymphoma in children should be differentiated from benign skin disorders that may simulate them. In particular, mycosis fungoides and LYP in this age group may present with clinicopathologic features reminiscent of inflammatory disorders such as pityriasis alba, vitiligo, pityriasis rosea, and pityriasis lichenoides et varioliformis acuta. Even in secondary cutaneous lymphomas, skin manifestations may be the first sign of the systemic disease, and a diagnosis may be achieved on examination of histopathologic specimens of a cutaneous lesion. Our study illustrates the wide spectrum of cutaneous lymphomas and leukemias in patients less than 20 years of age and underlines the need for proper interpretation of these lesions by dermatologists and dermatopathologists.

Adolescent↗