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Andreas Chott

Publications and source records attributed to Andreas Chott.

At least 37 records · Page 2Linked to original sources

Lymphoma-specific genetic aberrations in microvascular endothelial cells in B-cell lymphomas.

BACKGROUND: The growth of most tumors depends on the formation of new blood vessels. In contrast to genetically unstable tumor cells, the endothelial cells of tumor vessels are considered to be normal diploid cells that do not acquire mutations. METHODS: Using a combined immunohistochemical and fluorescence in situ hybridization assay, we examined the endothelial cells in 27 B-cell lymphomas for cytogenetic alterations that are known to be present in the lymphoma cells. RESULTS: We found that 15 to 85 percent (median, 37 percent) of the microvascular endothelial cells in the B-cell lymphomas harbored lymphoma-specific chromosomal translocations. In addition, numerical chromosomal aberrations were shared by the lymphoma cells and the endothelial cells. CONCLUSIONS: Our findings suggest that microvascular endothelial cells in B-cell lymphomas are in part tumor-related and therefore reflect a novel aspect of tumor angiogenesis.

Adult↗

Antitumor activity of rituximab plus thalidomide in patients with relapsed/refractory mantle cell lymphoma.

We evaluated a treatment strategy targeting both lymphoma cells (by rituximab) and the microenvironment (by thalidomide) in 16 patients with relapsed/refractory mantle cell lymphoma (MCL). Rituximab was administered at 375 mg/m(2) for 4 weekly doses concomitantly with thalidomide (200 mg daily, with a dose increment to 400 mg on day 15), which was continued as maintenance therapy until progression/relapse. Thirteen patients (81%) experienced an objective response, with 5 complete responders (31%). Median progression-free survival (PFS) was 20.4 months (95% confidence interval [CI], 17.3-23.6 months), and estimated 3-year survival was 75%. In patients achieving a complete response, PFS after rituximab plus thalidomide was longer than PFS after the preceding chemotherapy. Severe adverse events included 2 thromboembolic events and 1 grade IV neutropenia associated with thalidomide. Our results suggest that rituximab plus thalidomide has marked antitumor activity in relapsed/refractory MCL and a low toxicity profile, which warrants further evaluation in MCL.

Aged↗

Concomitant occurrence of MALT lymphoma and multiple myeloma.

The association between multiple myeloma and secondary malignancies is already well established. We report here on the concomitant occurrence of mucosa-associated lymphoid tissue (MALT) lymphoma and multiple myeloma. Despite the fact that both malignancies are mature B-cell neoplasms, the clinical approach to these two types of tumor is completely different. This paper describes the diagnostic approach to this particular case and presents immunophenotypic and molecular cytogenetic data suggesting that the two B-cell malignancies were clonally unrelated.

Aged↗

Frequency of chromosomal aberrations involving MALT1 in mucosa-associated lymphoid tissue lymphoma in patients with Sjögren's syndrome.

PURPOSE: Mucosa-associated lymphoid tissue (MALT) lymphoma develops in the context of longstanding antigenic stimulation such as infection with Helicobacter pylori or autoimmune disease, including Sjögren's syndrome (SS). Recently, two chromosomal aberrations involving the MALT1 gene, i.e., t(11;18)(q21;q21) and t(14;18)(q32;q21) have been reported as genetic events specific for MALT lymphoma. In view of the association between SS and the development of MALT lymphoma, we have analyzed the frequency of t(11;18)(q21;q21) and t(14;18)(q32;q21) in patients with MALT lymphomas arising in the background of SS. EXPERIMENTAL DESIGN: A retrospective analysis of patients diagnosed with MALT lymphoma and SS was performed. The t(11;18)(q21;q21) was analyzed using reverse transcriptase-PCR, whereas t(14;18)(q32;q21) was assessed by two-color interphase fluorescence in situ hybridization. RESULTS: Twenty-six patients (20 female and 6 male) with MALT lymphoma and SS could be identified. The lymphoma was located in the parotid (n = 14), orbit (n = 2), and submandibular gland (n = 1), whereas 9 patients had gastric MALT lymphoma. Seven of 26 patients (27%) harbored t(11;18)(q21;q21). Interestingly, only 1 of 17 patients (6%) with extragastrointestinal lymphoma was positive, as opposed to 6 of 9 patients (67%) with gastric MALT lymphoma. Four of 26 patients were positive for t(14;18)(q32;q21): 3 of 17 extragastrointestinal (18%) and 1 of 9 gastric lymphomas (11%). CONCLUSIONS: The overall frequency of MALT1 rearrangement appears to be low in patients with extragastrointestinal MALT lymphoma associated with SS. By contrast, MALT1 rearrangement was demonstrated in 7 of 9 patients (78%) with gastric MALT lymphoma and SS. This finding may explain at least in part why gastric MALT lymphomas in patients with SS are refractory to H. pylori eradication therapy.

Adult↗

FAS (CD95) mutations are rare in gastric MALT lymphoma but occur more frequently in primary gastric diffuse large B-cell lymphoma.

A loss of FAS (CD95) function has been proposed to constitute an important step in early mucosa-associated lymphoid tissue (MALT) lymphoma development and FAS mutations have been recognized in malignant lymphomas, in particular at extranodal sites. Since primary gastric lymphomas frequently exhibit resistance to FAS-mediated apoptosis, we investigated whether FAS is mutated in 18 gastric MALT lymphomas and 28 diffuse large B-cell lymphomas (DLBCL). We detected seven mutations in five lymphomas, one MALT lymphoma and four DLBCL; two DLBCL had two mutations. The MALT lymphoma exhibited a point mutation in the splice donor region of intron 3. Three DLBCL had missense mutations in exon 2, which encodes a signal peptide and a portion of the extracellular FAS ligand-binding domain. One DLBCL carried a point mutation in the splice donor region of intron 8, which would result in exon skipping. Two DLBCL harbored a missense mutation in exon 9, which encodes the intracellular death domain. The two death domain mutations inhibited FAS ligand-induced apoptosis in a dominant-negative mode, when transiently expressed in human T47D breast carcinoma and Jurkat T cells. A signal peptide and an extracellular domain mutation, however, failed to inhibit apoptosis in these transfection assays. They are likely to reduce apoptosis in lymphoma cells solely by a loss of function. In summary, our data show that FAS mutations are rare in primary gastric MALT lymphomas (5.6%) but occur in a subset of primary gastric DLBCL (14.3%) and suggest that these mutations contribute to the pathogenesis of gastric lymphomas by rendering lymphocytes resistant to apoptosis.

Apoptosis↗

Genomic profiling of peripheral T-cell lymphoma, unspecified, and anaplastic large T-cell lymphoma delineates novel recurrent chromosomal alterations.

To characterize genetic alterations in peripheral T-cell lymphoma, not otherwise specified (PTCL NOS), and anaplastic large T-cell lymphoma (ALCL), 42 PTCL NOS and 37 ALCL [17 anaplastic large cell kinase (ALK)-negative ALCL, 9 ALK-positive ALCL, 11 cutaneous ALCL] were analyzed by comparative genomic hybridization. Among 36 de novo PTCL NOS, recurrent chromosomal losses were found on chromosomes 13q (minimally overlapping region 13q21, 36% of cases), 6q and 9p (6q21 and 9p21-pter, in 31% of cases each), 10q and 12q (10q23-24 and 12q21-q22, in 28% of cases each), and 5q (5q21, 25% of cases). Recurrent gains were found on chromosome 7q22-qter (31% of cases). In 11 PTCL NOS, high-level amplifications were observed, among them 3 cases with amplification of 12p13 that was restricted to cytotoxic PTCL NOS. Whereas cutaneous ALCL and ALK-positive ALCL showed few recurrent chromosomal imbalances, ALK-negative ALCL displayed recurrent chromosomal gains of 1q (1q41-qter, 46%), and losses of 6q (6q21, 31%) and 13q (13q21-q22, 23%). Losses of chromosomes 5q, 10q, and 12q characterized a group of noncytotoxic nodal CD5+ peripheral T-cell lymphomas. The genetics of PTCL NOS and ALK-negative ALCL differ from other T-NHLs characterized genetically so far, among them enteropathy-type T-cell lymphoma, T-cell prolymphocytic leukemia, and adult T-cell lymphoma/leukemia.

Adolescent↗

Primary gastric mantle cell lymphoma in a patient with long standing history of Crohn's disease.

The stomach is the most common site of primary extranodal lymphoma. Virtually all cases are of B-cell lineage, including extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT lymphoma) and diffuse large B-cell lymphomas. While secondary gastric involvement from nodal mantle cell lymphoma (MCL) or in the course of primary intestinal MCL (lymphomatous polyposis) have been described, primary gastric MCL has not been reported so far. A 74-year-old man with a 14 year-history of Crohn's disease was admitted at a general hospital due to epigastric pain refractory to therapy with proton-pump inhibitors. Endoscopy disclosed a large polypoid tumor with an ulcerated surface at the greater curvature of the gastric antrum. Endosonography demonstrated the tumor to be limited to the stomach with only local lymph node involvement. Histology of gastric biopsies revealed a dense atypical lymphoid infiltrate composed of small to medium sized cells with slightly irregular nuclear contours. Immunohistochemichally, the cells were positive for CD20, CD79a, CD43 and cyclin D1, but negative for CD3, CD5 and bcl-6. They stained for IgM and showed lambda-light chain restriction. Fluorescent in situ hybridisation studies showed the presence of the t(11;14) characteristic for MCL. No further evidence of lymphoma was found on extensive clinical staging. Following chemotherapy the patient is disease free at 24 months after diagnosis. This is the first case of a primary localized gastric MCL. The lack of CD5 expression underscores the importance of performing thorough immunohistochemical studies, particularly to exclude MALT lymphoma.

Aged↗

Bone marrow microvessel density and its prognostic significance in AML.

Microvessel density reportedly is increased in various hematologic disorders including acute lymphatic and myeloid leukemias. In these patients the bone marrow microvessel density (BM-MVD) appears to be associated with an unfavorable prognosis. In the present study, we have retrospectively analyzed the BM-MVD (at diagnosis) in 31 patients with acute myeloid leukemia (AML) (median age: 38 years; range: 21-53 years; f:m-ratio: 1:1,4) who underwent conventional chemotherapy and consecutive allogeneic bone marrow transplantation (BMT). The median BM-MVD at diagnosis was 30/mm2 (range: 17-48/mm2) and thus was significantly higher compared to controls (n = 9; BM-MVD: median 7/mm2, range 2-11/mm2; P < 0.05). In patients who failed to achieve a complete remission (CR) in response to induction chemotherapy, the BM-MVD was significantly higher (median: 41.5/mm2) at diagnosis than in patients who entered CR (median: 28.5/mm2, P < 0.05). In addition, patients with high BM-MVD ( > 30 mm2) had a significantly shorter overall survival compared to patients with a lower BM-MVD ( < 30 mm2, P < 0.05). Moreover, patients with a high BM-MVD ( > 30 mm2) were found to have a significantly higher risk of relapse (P < 0.05). In 4 patients in whom a continuous complete remission was documented after BMT, the BM-MVD levels were analyzed at diagnosis as well as between day + 80 and day + 100 after BMT. In all 4 patients, the BM-MVD was found to decrease in response to BMT until day 100 (P < 0.05). Together, our data suggest that the BM-MVD could be a prognostic parameter concerning survival in patients with AML undergoing allogeneic BMT.

Acute Disease↗

Differential diagnosis of cutaneous infiltrates of B lymphocytes with follicular growth pattern.

The differential diagnosis of cutaneous B-cell infiltrates with follicular pattern of growth is one of the most vexing problems in dermatopathology. In this study we focused on histopathologic, immunophenotypic, and molecular differential diagnostic criteria between Borrelia burgdorferi (Bb)-associated lymphocytoma cutis (LC), primary cutaneous follicle center cell lymphoma (FCCL), and primary cutaneous marginal zone lymphoma (MZL) with reactive germinal centers (GCs). A total of 47 patients were included in the study, including 12 cases of LC (M:F = 2:1; mean age: 38.0; median: 31; range: 9-75), 29 cases of FCCL (M:F = 1.2:1; mean age: 57.5; median: 57; range: 24-97), and 6 cases of MZL (M:F = 1:1; mean age: 63.8; median: 67.5; range: 38-86). In all cases complete phenotypic data were available. In addition, the IgH gene rearrangement and the t(14;18) were analyzed using the polymerase chain reaction technique (PCR) in 41 (FCCL = 27, LC = 10, MZL = 4) and 18 cases (FCCL = 15, LC = 2, MZL = 1), respectively. Histology revealed in all cases of FCCL one or more atypical feature of the follicles including the lack of or a reduced mantle zone, lack of polarization, tendency to confluence, and absence of tingible body macrophages. In most cases of Bb-associated LC, the GCs were devoid of mantle zone, lacked polarization, and revealed tendency to confluence as well, but all cases showed the presence of several tingible body macrophages. In MZL, follicles showed typical features of reactive GCs. Immunohistology revealed a reduced proliferative activity of neoplastic follicles as detected by MIB-1 antibody in 23 of 29 cases of FCCL (79.3%), but only in 1 case of LC (8.3%). Proliferation of the GCs was normal in all cases of MZL. Positivity for CD10 and/or Bcl-6 was found in small clusters outside the follicles in 19 cases of FCCL (65.5%), and in 3 cases of LC (25%), but in no case of MZL. The intensity of CD10 staining on follicular cells on average was stronger in cases of FCCL, but overlapping features could be observed. Finally, staining for Bcl-2 protein was consistently negative on GC cells in cases of LC and MZL, and was positive on a variable proportion of the cells in 8 cases of FCCL (28.6%). Molecular analyses showed no evidence of the t(14;18) in all cases tested. Analysis of the IgH gene rearrangement revealed a monoclonal pattern in 1 of 10 cases of LC (10%), 14 of 27 cases of FCCL (51.9%), and 2 of 4 cases of MZL (50%) tested. In summary, Bb-associated LC and FCCL show sometimes overlapping histopathologic, immunohistochemical, and molecular features, whereas follicles in MZL show clear-cut aspects of reactive GCs. Absence of tingible body macrophages within follicles, reduced proliferation of the follicles as detected by immunohistology, presence of positivity for Bcl-2 protein within follicular cells, and monoclonality by PCR are the main criteria suggestive of malignancy. Diagnosis of cutaneous infiltrates of B lymphocytes with follicular growth pattern should be achieved by integration of clinical data with histopathologic, immunohistochemical, and molecular features of the lesions.

Adolescent↗

Severe malabsorption due to refractory celiac disease complicated by extensive gastric heterotopia of the jejunum.

Refractory celiac disease denotes that patients considered to have celiac disease fail to respond histologically to treatment with a gluten-free diet. Among several causes of nonresponsiveness, enteropathy-type T-cell lymphoma is most important because of its almost invariably rapid lethal outcome. We present the case of a 44-year-old patient with refractory celiac disease complicated by unusually severe malabsorption. Repeated duodenal biopsies disclosed normal and slightly shortened villi, focal crypt hypertrophy, and a moderate increase of intraepithelial lymphocytes consistent with celiac disease, but unable to explain the severe malabsorption. To rule out cryptic lymphoma, push enteroscopy was done providing 21 biopsies taken along the entire jejunum. Surprisingly, about 70% of the biopsies were composed of gastric glands covered by nonabsorptive-type, strongly periodic acid-Schiff-positive surface epithelium and showed a villous architecture. Alternating with the gastric mucosa, there were areas of flat mucosa with elongated crypts and occasional erosions. Irrespective of the type of surface epithelium, intraepithelial lymphocytes were increased with counts up to 80/100 epithelial cells. Despite harboring an aberrant immunophenotype, overt T-cell lymphoma was ruled out histologically and by lack of monoclonality, as tested by polymerase chain reaction. To the best of our knowledge, this is the first case of refractory celiac disease complicated by extensive jejunal gastric heterotopia, which might have contributed to the severe malabsorption.

Adult↗

Subcutaneous, blastic natural killer (NK), NK/T-cell, and other cytotoxic lymphomas of the skin: a morphologic, immunophenotypic, and molecular study of 50 patients.

A new group of subcutaneous, natural killer (NK), NK/T-cell, and other cytotoxic T-cell lymphomas of the skin has been recently described, and some have been included as distinct clinicopathologic entities in the classification of hematologic malignancies recently proposed by the World Health Organization. In the European Organization for Research and Treatment of Cancer classification for cutaneous lymphomas, they would be classified either as CD30- large T-cell lymphoma, small/medium pleomorphic T-cell lymphoma, or subcutaneous T-cell lymphoma. Precise clinicopathologic and prognostic features of all of them have not yet been well characterized. We studied retrospectively 81 biopsies from 50 patients with subcutaneous, blastic natural killer (NK), NK/T-cell, or other non-mycosis fungoides cytotoxic T-cell lymphomas of the skin. Clinical, morphologic, phenotypical, and genetic features and data on Epstein-Barr virus association allowed us to classify our cases according to the following 7 categories: a) subcutaneous "panniculitis-like" T-cell lymphoma (SPTCL): 10 cases (estimated 5-year survival: 80%); b) blastic NK-cell lymphoma: 12 cases (estimated 5-year survival: 0%); c) nasal-type extranodal NK/T-cell lymphoma: 5 patients (estimated 5-year survival: 0%); d) epidermotropic CD8+ T-cell lymphoma: 5 cases (estimated 5-year survival: 0%); e) cutaneous gamma/delta T-cell lymphoma: 8 cases (estimated 5-year survival: 0%); f) cutaneous alpha/beta pleomorphic T-cell lymphoma: 8 cases (estimated 5-year survival: 0%); and g) cutaneous medium/large pleomorphic T-cell lymphoma, not otherwise specified: 2 cases. Our study shows that these cutaneous lymphomas can be classified according to precise diagnostic categories. With the exception of SPTCL, analysis of follow-up data from our patients showed that these groups of lymphomas are characterized by an aggressive course, regardless of the diagnostic category.

Adult↗

Borrelia burgdorferi-associated lymphocytoma cutis: clinicopathologic, immunophenotypic, and molecular study of 106 cases.

Lymphocytoma cutis (LC) is considered as the stereotypical example of the cutaneous B-cell pseudolymphomas. It can be induced by various antigenic stimuli including arthropod bites, vaccination, and drugs among others. In endemic regions, Borrelia burgdorferi is the principal causative agent for LC. We studied retrospectively 108 biopsies from 106 patients (male : female, 48 : 58; mean age, 44.6; median, 51.5; range, 3-81) with B. burgdorferi-associated LC retrieved from the files of the Department of Dermatology of the University of Graz (Austria). Only cases with a B. burgdorferi etiology (typical locations, positivity of serologic and/or polymerase chain reaction (PCR) tests, clinical history) were included in the study. Lesions were located on the nipple (63 cases), earlobe (18 cases), genital region (9 cases), and trunk or extremities (16 cases). PCR analysis of B. burgdorferi DNA was positive in 54 of 80 cases tested (67.5%). In 47 cases, we could retrieve data on serologic examination for B. burgdorferi antibodies performed at the time of diagnosis of LC. Positivity was found in 45 patients (IgG+/IgM+, 5 cases; IgG+/IgM-, 37 cases; IgG-/IgM+, 3 cases; IgG-/IgM-, 2 cases). Histology revealed dense lymphoid infiltrates with prominent germinal centers (GCs) in all cases. Atypical morphologic and/or immunophenotypic features of the GCs were commonly observed. In 5 cases, due to confluence of large follicles, the histopathologic pattern simulated that of a large B-cell lymphoma. PCR analysis of the IgH gene rearrangement performed in 33 cases showed a polyclonal pattern in 31 cases and a monoclonal band in 2. In summary, B. burgdorferi-associated LC can present with misleading histopathologic, immunophenotypic, and molecular features, and integration of all data is necessary for a correct diagnosis.

Adolescent↗

Translocation t(11;18)(q21;q21) is not predictive of response to chemotherapy with 2CdA in patients with gastric MALT lymphoma.

BACKGROUND: t(11;18)(q21;q21) resulting in the API2-MALT1 fusion transcript is an exclusive finding in extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). While it has recently been demonstrated as a negative predictor for gastric MALT lymphoma undergoing eradication of Helicobacter pylori, nothing is known about the relation between t(11;18)(q21;q21) status and response to chemotherapy. We have therefore performed a retrospective analysis of t(11;18)(q21;q21) in patients undergoing chemotherapy with the nucleoside analogue cladribine (2CdA) for gastric MALT lymphoma. PATIENTS AND METHODS: Eighteen cases of gastric MALT lymphoma treated with 2CdA were reviewed, and 17 could be investigated for t(11;18)(q21;q21) by reverse-transcription polymerase chain reaction and fluorescence in situ hybridization. t(11;18)(q21;q21) was correlated with response to chemotherapy. RESULTS: Of the 17 patients with gastric MALT lymphoma treated with 2CdA, 9 were at stage IE, 2 at stage IIE and 6 at stage IV. Eight cases with stage IE lymphoma were first treated with H. pylori eradication, but none of them showed histological regression during a minimum follow-up of 12 months, and they were subsequently treated with primary chemotherapy. One patient received chemotherapy due to absence of H. pylori infection. Another patient initially rated as stage IE whose gastric lymphoma did not respond developed spread to the lung during follow-up after eradication. All the remaining 13 cases were treated by chemotherapy at the time of diagnosis. Out of these 17, 8 patients (47%) were found to carry t(11;18)(q21;q21). One patient, who was negative for t(11;18)(q21;q21), progressed during chemotherapy and died 5 months after initiation of treatment. One patient each with and without t(11;18)(q21; q21) had a partial response lasting for 14 and >18 months, respectively. One t(11;18)(q21;q21)-positive patient had stable disease for >16 months. The remaining patients achieved a complete remission (CR) following treatment; 6 were positive for t(11;18)(q21;q21), while the remaining 6 were negative. Two patients [1 positive and 1 negative for t(11;18)(q21;q21), respectively] have developed a local relapse following CR and were salvaged by radiotherapy. CONCLUSION: Our findings suggest that the presence of the API2-MALT1 fusion transcript resulting from t(11;18)(q21;q21) does not adversely affect the response of gastric MALT lymphoma to chemotherapy with 2CdA. 2CdA appears to be an attractive agent for treatment of gastric MALT lymphoma unresponsive to H. pylori eradication, including those positive for t(11;18)(q21;q21).

Adult↗

18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) does not visualize follicular lymphoma of the duodenum.

18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) has been used as a potential tool for imaging nodal follicular lymphoma (FL) and extranodal spread. As primary intestinal FL is increasingly being recognized, we have performed a study to investigate the usefulness of 18F-FDG-PET for staging of extranodal FL within the gastrointestinal tract. In eight patients with a diagnosis of FL localized in the duodenum (six cases in stage I and one each in stages II and IV, respectively) whole body 18F-FDG-PET scans were performed. Seven patients with duodenal FL were rated WHO grade 1 and one had FL grade 3, while both patients with secondary spread had FL WHO grade 1. All patients were imaged before initiation of therapy. None of the patients with primary duodenal FL showed pathologically elevated 18F-FDG uptake. 18F-FDG-PET findings were not influenced by histological grade or proliferative activity of FL. These findings suggest that 18F-FDG-PET is not useful for clinical assessment of primary duodenal FL.

Adult↗

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue of the head and neck area: high rate of disease recurrence following local therapy.

BACKGROUND: Mucosa-associated lymphoid tissue (MALT) lymphoma is a distinct entity with specific clinical and pathologic features that may affect diverse organs. MALT-lymphomas remain localized within their original environment for a long period of time. As recent data have demonstrated a relatively high rate of multiorgan involvement at diagnosis, the authors have retrospectively evaluated 36 patients presenting with MALT-lymphoma in the head and neck area. The authors focused on patients' disease localization, initial treatment, clinical course, and follow-up. METHODS: Thirty-six patients with a histologically verified diagnosis of an extranodal marginal zone B-cell MALT-lymphoma arising in the head and neck area were included in this retrospective analysis. RESULTS: Treatment consisted of surgical resection as the sole treatment in 4 patients (11%), surgical resection with consecutive radiotherapy in 13 patients (36%), radiotherapy alone in 11 patients (31%), chemotherapy in 2 patients (6%), surgical resection plus radiotherapy and chemotherapy in 4 patients (11%), and combined radiation and chemotherapy in 1 patient (3%). Complete and partial disease remissions after initial treatment were achieved in 22 (61%) and 13 patients (36%), respectively, whereas one patient refused any therapy. Four patients (11%) were lost to follow-up and 15 patients (43%) have had disease recurrence after a median time of 11 months (range, 3-80 months). CONCLUSIONS: These data suggest that MALT-lymphomas of the head and neck area are preferentially treated using local modalities such as radiation and/or resection. This practice, however, is associated with an unexpectedly high rate of dissemination or disease recurrence. Obtaining an initial complete response is crucial in these patients. According to previous data, the possibility of understaging in such patients cannot be ruled out. Clinical trials with application of systemic treatment are warranted for these patients.

Adult↗

Cytotoxic/natural killer cell cutaneous lymphomas. Report of EORTC Cutaneous Lymphoma Task Force Workshop.

BACKGROUND: Cutaneous lymphomas expressing a cytotoxic or natural killer (NK) cell phenotype represent a group of lymphoproliferative disorders for which there is currently much confusion and little consensus regarding the best nomenclature and classification. METHODS: This study analyzes 48 cases of primary cutaneous lymphoma expressing cytotoxic proteins and/or the NK cell marker, CD56. These cases were collected for a workshop of the European Organization for Research and Treatment of Cancer Cutaneous Lymphoma Task Force, to better clarify the clinical, morphologic, and phenotypic features of these uncommon tumors. RESULTS: Several categories with different clinical and pathologic features were delineated: 1) aggressive, CD8+, epidermotropic, cytotoxic T-cell lymphoma; 2) mycosis fungoides, cytotoxic immunophenotype variant; 3) subcutaneous panniculitis-like T-cell lymphoma; 4) NK/T-cell lymphoma, nasal type; 5) CD4+, NK cell lymphoma; 6) blastoid NK cell lymphoma; (7) intravascular NK-like lymphoma; and 8) cytotoxic, peripheral T-cell lymphoma. CONCLUSIONS: Our data show that primary cutaneous cytotoxic/NK cell lymphomas include distinct groups of diseases, clinically, histologically, and biologically. Because the finding of a cytotoxic phenotype often has prognostic significance, the routine use of cytotoxic markers in the diagnosis and classification of cutaneous lymphomas should be expanded.

CD4-Positive T-Lymphocytes↗

Mutual exclusion of t(11;18)(q21;q21) and numerical chromosomal aberrations in the development of different types of primary gastric lymphomas.

Gastric non-Hodgkin's lymphomas can be divided histologically into mucosa-associated lymphoid tissue (MALT) lymphoma (ML) and diffuse large cell lymphoma (DLCL) with or without evidence of preceding/accompanying ML (DLCL + ML). We studied the incidence of the most frequent structural chromosomal aberration in ML, t(11;18)(q21;q21), and numerical aberrations of seven chromosomes in 36 ML, 39 DLCL + ML and ten gastric DLCL cases, by dual-colour interphase fluorescence in situ hybridization (FISH) and reverse transcriptase polymerase chain reaction (RT-PCR). t(11;18)(q21;q21) was exclusively detected in ML (FISH 22%; RT-PCR 24%), being completely absent in DLCL + ML and DLCL. No other translocations involving 11q21 or 18q21 and other partner chromosomes were detected by FISH. In lymphomas harbouring t(11;18)(q21;q21), this translocation was the sole genetic abnormality. In contrast, 45% of the t(11;18)(q21;q21)-negative ML showed trisomies, especially of chromosome 3 and 18. In DLCL + ML with separate small and large cell components, trisomies were either detected in both components or occurred exclusively in large tumour cells. Our results suggest that ML can be divided in lymphomas characterized by the t(11;18)(q21;q21), which are unlikely to transform into high-grade tumours, and t(11;18)(q21;q21)-negative ML that may develop into DLCL + ML after the acquisition of additional genetic aberrations.

Chromosomes, Human, Pair 11↗

Morphologic and immunophenotypic properties of neoplastic cells in a case of mast cell sarcoma.

Mast cell sarcoma is an extremely rare and aggressive type of mast cell disease. Only a few cases have been described so far, and little is known about the biology and phenotype of afflicted cells. We describe morphologic and immunophenotypic properties of neoplastic mast cells in a case of an intracranial mast cell sarcoma. In Wright-Giemsa-stained cytospin preparations, the morphology of dispersed cells appeared to be highly atypical with a considerable percentage of metachromatic blasts and mast cells with bilobed or multilobed nuclei. Combined toluidine blue/immunofluorescence staining revealed expression of CD13, CD45, CD88, CD116, and CD117 (c-KIT) on neoplastic mast cells. As assessed by immunohistochemistry, mast cells were immunoreactive for tryptase and CD68R, In contrast, the CD2 antigen that is expressed in mast cells in patients with indolent systemic mastocytosis was not detectable. Mast cells also failed to display the c-KIT mutation Asp-816-Val, which is typically found in systemic mast cell disorders. Together, neoplastic mast cells in a case of mast cell sarcoma were found to exhibit unique morphologic, phenotypical, and molecular features when compared with mast cells in indolent mastocytosis or normal tissue mast cells.

Antigens, CD↗