T-cell lymphomas of the stomach: morphological and immunological studies characterizing two cases of T-cell lymphoma

Anaplastic large cell lymphoma: twenty-five years of discovery

CONTEXT

The year 2010 commemorates the 25th year since the seminal publication by Karl Lennert and Harald Stein and others in Kiel, West Germany, describing an unusual large cell lymphoma now known as anaplastic large cell lymphoma (ALCL). Investigators at many universities and hospitals worldwide have contributed to our current in-depth understanding of this unique peripheral T-cell lymphoma, which in its systemic form, principally occurs in children and young adults.

OBJECTIVE

To summarize our current knowledge of the clinical and pathologic features of systemic and primary cutaneous ALCL. Particular emphasis is given to the biology and pathogenesis of ALCL.

DATA SOURCES

Search of the medical literature (Ovid MEDLINE In-Process & Other Non-Indexed Citations and Ovid MEDLINE: 1950 to Present [National Library of Medicine]) and more than 20 years of diagnostic experience were used as the source of data for review.

CONCLUSIONS

Based on immunostaining for activation antigen CD30 and the presence of dysregulation of the anaplastic lymphoma kinase gene (2p23), the diagnosis of ALCL has become relatively straightforward for most patients. Major strides have been made during the last decade in our understanding of the complex pathogenesis of ALCL. Constitutive NPM-ALK signaling has been shown to drive oncogenesis via an intricate network of redundant and interacting pathways that regulate cell proliferation, cell fate, and cytoskeletal modeling. Nevertheless, pathomechanistic, therapeutic, and diagnostic challenges remain that should be resolved as we embark on the next generation of discovery.

Clinicopathological characteristics of primary gastric T-cell lymphoma

AIMS

To investigate the clinicopathological characteristics of 20 primary gastric T-cell lymphoma (GTCL) cases without human T-lymphotropic virus type I infection in Japan, a non-endemic area for coeliac disease.

METHODS AND RESULTS

Fifteen cases had no history of persistent diarrhoea or severe hypoproteinaemia. Histologically, 13 cases (65%) consisted of large cell lymphoma and seven (35%) were of medium-sized cells. Intraepithelial lymphoma cell invasion was found in three cases (15%). Two of 10 surgical cases (20%) showed intramucosal tumour cell spreading with enteropathy-like features. Helicobacter pylori CagA gene was detected in three of 10 cases (30%). The lymphoma cells of all 20 cases were positive for CD3 and/or TCRbetaF1 and negative for CD56. CD4- and CD8- lymphoma was found in 11 cases (55%), CD4+ lymphoma in seven (35%) and CD8+ lymphoma in two (10%). CD30+, CD5+ and CD25+ lymphomas were detected in nine (45%), 10 (50%) and 11 (55%) cases, respectively. Five-year survival of the 16 available cases was 54%. Early clinical stage and medium-sized cell lymphoma were significantly (P < 0.05) better prognostic factors.

CONCLUSIONS

Patients with GTCL exhibit distinct clinicopathological findings and prognoses from those with enteropathy-associated T-cell lymphomas. GTCL may be mainly derived from lamina propria and parafollicular T cells.

Primary gastric T cell lymphoma mimicking marginal zone B cell lymphoma of mucosa-associated lymphoid tissue

Primary gastric T cell lymphoma is rare and mostly of large cell type. In this paper, we present a case of gastric T cell lymphoma morphologically similar to the gastric marginal zone B cell lymphoma of mucosa-associated lymphoid tissue (MALT). Morphologically, the cells are small with abundant clear cytoplasm. Lymphoepithelial lesions are readily identified with diffuse destruction of gastric glands. Immunohistochemically, the neoplastic cells are CD3+/CD4+/CD8−/Granzyme B−. Molecular studies revealed monoclonal T cell receptor γ gene rearrangement. Clinically, the patient responded initially to four cycles of R-CHOP, but then progressed. Because peripheral T cell lymphoma is usually associated with a poor prognosis, whereas marginal zone B cell lymphoma is an indolent lymphoproliferative disorder, this morphologic mimicry should be recognized and completely investigated when atypical small lymphoid infiltrates with lymphoepithelial lesions are encountered in the stomach.

Malignant neoplasms of the appendix

BACKGROUND

Appendiceal neoplasms, first described in 1882, are still rare, with pre-operative diagnosis invariably difficult. We present our 10-year experience of these lesions with a review of current epidemiology, pathology and treatment modalities.

MATERIALS AND METHODS

A retrospective histopathological review of all appendicectomy specimens was completed between April 1994 and December 2003 to identify patients diagnosed with malignant neoplasms. Patient demographics, operative details, histopathology and clinical outcomes were obtained from case notes. A literature search of the PubMed database was then performed using the medical search headings; appendix, tumour, neoplasm and malignancy.

RESULTS

Twenty-two patients (eight men) were identified during the study period, with no age difference between gender (mean age in women 58, range 14-83 vs mean age in men 55, range 16-78). Eleven patients were found to have carcinoid-type tumours, eight patients with adenocarcinomas and three patients with lymphomas. Other appendiceal pathologies were identified after appendicectomies, hemicolectomy and oophorectomy. Mean follow-up was 41 months (range 1-125 months). Fourteen patients were alive at the end of follow-up. Patients with classical carcinoid tumours (CCT) had better outcomes than patients with the goblet cell carcinoid, adenocarcinoma and lymphoma.

CONCLUSIONS

From our own experience and a subsequent review of the literature, we recommend right hemicolectomy as the treatment of choice for all malignant appendiceal neoplasms, except for small CCT less than 2 cm in diameter at the tip of the appendix, with a low proliferative index, without angiolymphatic or mesoappendiceal extension. Further adjuvant therapy should be considered after oncological assessment.

Primary lymphohistiocytic variant of anaplastic large cell lymphoma of the stomach

Here, we report an unusual case of gastric anaplastic large cell lymphoma (ALCL), lymphohistiocytic variant, in a 70-year-old female patient who presented with epigastric pain, tarry stool and body weight loss. Endoscopic and imaging findings revealed a Bormann type II tumor in the stomach with perigastric lymphadenopathy and multiple tumor nodules in the liver. Total gastrectomy and liver biopsy were performed. Histologically, both gastric and hepatic tumors demonstrated anaplastic large neoplastic cells scattered among numerous reactive histiocytes. Immunostaining of these tumor cells reacted positively for CD30, CD3, CD45 RO/UCHL1, and negatively for epithelial membrane antigen, CD68, lysozyme, CD15, CD79a, CD138, PAX5 and anaplastic lymphoma kinase. Both the morphologic and immunophenotypic findings supported the diagnosis of gastric ALCL of lymphohistiocytic variant with liver metastasis. This patient then received chemotherapy and was still alive after 17 months of follow-up, without evidence of residual disease.

Primary gastric lymphoma

AIM: The purpose of this review is to describe the various aspects of primary gastric lymphoma and the treatment options currently available.

METHODS: After a systematic search of Pubmed, Medscape and MDconsult, we reviewed and retrieved literature regarding gastric lymphoma.

RESULTS: Primary gastric lymphoma is rare however, the incidence of this malignancy is increasing. Chronic gastritis secondary to Helicobacter pylori (H pylori) infection has been considered a major predisposing factor for MALT lymphoma. Immune histochemical marker studies and molecular biology utilizing polymerase chain reaction have facilitated appropriate diagnosis and abolished the need for diagnostic surgical resection. Advances in imaging techniques including Magnetic Resonance Imaging (MRI) and Endoscopic Ultrasonography (EUS) have helped evaluation of tumor extension and invasion. The clinical course and prognosis of this disease is dependent on histopathological sub-type and stage at the time of diagnosis. Controversy remains regarding the best treatment for early stages of this disease. Chemotherapy, surgery and combination have been studied and shared almost comparable results with survival rate of 70%-90%. However, chemotherapy possesses the advantage of preserving gastric anatomy. Radiotherapy alone has been tried and showed good results. Stage IIIE, IVE disease treatment is solely by chemotherapy and surgical resection has been a remote consideration.

CONCLUSION: We conclude that methods of diagnosis and staging of the primary gastric lymphoma have dramatically improved. The modalities of treatment are many and probably chemotherapy is superior because of high success rate, preservation of stomach and tolerable complications.

Primary T-cell non-Hodgkin's malignant lymphoma of the appendix

A case of primary T-cell lymphoma of the appendix in an 84-year-old female was reported. Appendectomy was performed as a result of the clinical diagnosis of acute appendicitis, due to the rebound tenderness of McBurney's point and thickness of the appendix wall as determined from ultra echo sonograph. Grossly, the surgical resected appendix did not have a dominant inflammatory appearance, therefore a tumor was suspected. Microscopic examination showed diffused proliferation of large and medium size lymphoma cells. Immunohistochemical examination further revealed that the lymphoma cells were positive for T-cell markers. To ensure this was a T-cell lymphoma, molecular examination was performed using paraffin-embedded tissue sections, since T-cell lymphoma of the appendix is extremely rare. Polymerase chain reaction (PCR) single-strand conformation polymorphism (SSCP) analysis demonstrated monoclonal T-cell receptor gene rearrangement. T-cell-rich B-cell lymphoma was excluded. To our knowledge, this is the first reported case of primary T-cell lymphoma of the appendix. PCR-SSCP analysis in paraffin-embedded tissue section was very useful in the diagnosis of lymphoma cell monoclonality.

Primary gastric T-cell lymphomas: report of two cases and a review of the literature

To understand more fully the clinicopathological features of primary gastric T-cell lymphomas (PGTL), we report two cases of PGTL and review the literature. The present cases were not associated with human T-cell leukemia virus type 1 (HTLV-1) and were at clinical stage IIE. In both cases, T-cell origin of the lymphoma cells was diagnosed immunohistochemically. The clinical courses of these two cases were different: one followed a very aggressive clinical course and the patient died 6 months after the diagnosis, whereas the other patient survived more than 2 years without adjuvant chemotherapy. Clinicopathological features of 23 patients with PGTL are summarized with regard to their differences from primary small intestinal T-cell lymphomas (PSITL) and by association with HTLV-1. The median age at onset of PGTL was 58 years. The gender ratio was male-dominant (M:F = 2.3:1). About two-thirds (10 of 17) of PGTL cases had evidence of HTLV-1 infection. The most common presenting symptom for PGTL was upper abdominal discomfort and/or pain (76%), whereas that in PSITL was weight loss (61%) and diarrhea (42%). Typical lesions for PGTL were large ulcerations at the corpus to antrum. Neoplastic cells had no typical morphological characteristics for PGTL including HTLV-1-associated cases. CD3+4+8- was the most frequently observed surface phenotype of PGTL cells. Laboratory findings at diagnosis were not informative. Most patients were treated by gastrectomy with or without chemotherapy. PGTL, excluding that with HTLV-1, showed better prognosis than PSITL, although PGTL with HTLV-1 had a poorer prognosis.

Origin of primary gastric T-cell lymphomas from intraepithelial T-lymphocytes: report of two cases

AIMS

The classification of primary gastric T-cell lymphomas is uncertain due to the exceeding rarity of these tumours; many of the reported cases were felt to be similar to node-based lymphomas. We describe two cases of primary gastric T-cell lymphoma with evidence of origination from intraepithelial T-lymphocytes.

METHODS AND RESULTS

Both tumours were restricted to the stomach; one displaying a large ulcerated mass, the other a widespread superficial tumour manifestation. Histologically the first tumour was composed of sheets of medium-sized lymphoid cells showing marked epitheliotropism at the edge of the ulcer, and a CD3+, CD4-, CD8-, CD20-, CD56-, CD103+, beta F1+ phenotype. The second case differed histologically and immunophenotypically from the first case. In addition to lamina propria and submucosal infiltration, the lymphoma contained an extensive intraepithelial component even in large areas without other evidence of tumour. The neoplastic cells ranged in size from small to medium and large. Immunohistology disclosed a CD3+, CD4+, CD8-, CD20-, CD56-, beta F1+ phenotype. Staining for CD103 could not be performed in this case since frozen material was not available.

CONCLUSIONS

The prominent epitheliotropism, the marked intraepithelial growth and the expression of CD103 strongly imply a derivation of these primary gastric lymphomas from intraepithelial T-lymphocytes. Additional studies of larger series will clarify whether the findings described here are typical of primary gastric T-cell lymphomas.

Genotype configuration in a case of primary gastric lymphoma with T-cell phenotype

T-cell malignant lymphoma of the gastrointestinal tract is rare. The genotype of gastric T-cell lymphoma remains unclear. The aim of this study was to elucidate the pathogenesis of a case of primary gastric T-cell lymphoma by using cytogenetics and molecular biology. Gastric biopsy specimens and lymphoma cells in the ascites were examined by immunocytology, cytogenetic analysis, and Southern blot analysis. The histological diagnosis of the gastric lymphoma was diffuse large cell type. T-cell markers were positive in immunocytochemistry of the gastric lymphoma cells and in FACS analysis of lymphoma cells in the ascites. All lymphoma cells in the ascites had complex abnormal karyotypes containing t(8;14)(q24;q32). Southern blot analysis revealed rearrangement of the IgH and C-MYC genes of the lymphoma cells in both the stomach and the ascites, but no comigration of the C-MYC with the JH locus could be detected. The TCR-beta and -gamma genes were in their germ-line configurations. In this patient, although the phenotype was T-cell lymphoma, the karyotype t(8;14)(q24;q32) and genotype had the characteristics of B-cell lymphoma. The unique B-cell genotype configuration and the C-MYC activation suggested that the cellular origin of this rare case of malignant lymphoma with a T-cell phenotype was quite immature lymphocytes.

Primary gastric T-cell lymphoma with and without human T-lymphotropic virus type 1

BACKGROUND

Gastric T-cell lymphomas are rare, and their incidence and viral status have not yet been fully clarified.

METHODS

Sixty-seven cases of surgically resected gastric lymphomas from city hospitals in Tokyo were evaluated. The surface phenotype was determined by immunohistochemistry, gene rearrangement by Southern blot hybridization, association with Epstein-Barr virus (EBV) by EBV-encoded small RNAs in situ hybridization, and the presence of human T-cell lymphotropic virus type 1 (HTLV-1) by serology, Southern blot hybridization, and polymerase chain reaction analysis.

RESULTS

Five of the 67 cases were T-cell lymphoma (7%): 3 cases were HTLV-1 negative (-) and 2 were HTLV-1 positive (+). Systemic eosinophilia was observed in the three HTLV-1(-) gastric lymphomas. Neoplastic cells were morphologically similar in both groups, but a granulomatous reaction with marked eosinophilia was observed only in the two cases of HTLV-1(-) lymphoma. They also had characteristics of natural killer (NK) cell-like T-cell lymphoma, expressing NK markers and TCRgamma gene rearrangement. Positivity with HML-1 (specific for intestinal epithelial T-cells lymphoma was observed in one HTLV-1(+) lymphoma. The EBV gene was detected in only one case of B-cell lymphoma but not in any case of T-cell lymphoma.

CONCLUSIONS

Gastric T-cell lymphoma occurs in 7% of gastric lymphomas in Japan and is comprised of HTLV-1-related lymphomas and lymphomas unrelated to HTLV-1, including NK cell-like lymphomas with eosinophilia.

Case report: primary CD30 (Ki-1)-positive anaplastic large cell lymphoma of the duodenum

As recently described, Ki-1 anaplastic large cell lymphoma is a distinctive subtype of non-Hodgkin's lymphoma. We report a Ki-1 anaplastic large cell lymphoma of the duodenum in a 62-year-old man. He received modified CHOP therapy and was in complete remission at 18 months. To our knowledge, this is the first report of primary Ki-1 anaplastic large cell lymphoma of the duodenum.

Primary gastric lymphomas: morphologic, immunohistochemical and immunogenetic analyses

Morphologic, immunohistochemical and immunogenetic studies were performed on 28 cases of primary gastric lymphoma from fresh frozen tissue. Eight cases were diagnosed as diffuse large B-cell lymphoma, four as follicular center lymphoma (follicular), five as mucosa-associated lymphoid tissue (MALT) lymphoma, three as plasmacytoma, and three as T-cell lymphoma, two as mantle cell lymphoma, one as follicular center lymphoma (diffuse, predominantly small cell), and one as lymphoplasmacytoid lymphoma, and one as Hodgkin's disease. From immunohistochemical studies, four types of morphologically similar low-grade lymphomas can be differentiated by a combination of various monoclonal antibodies. Cases of diffuse large B-cell lymphoma may have a germinal center origin. We observed lympho-epithelial lesions in cases of non-MALT lymphomas. We therefore consider that the current diagnostic criterion for MALT lymphoma may not always be valid. Except for cases of T-cell lymphoma and Hodgkin's disease, 17 out of 22 cases revealed clonal rearrangement bands of the JH gene. In situ hybridization (ISH) and polymerase chain reaction (PCR) studies revealed the presence of Epstein-Barr (EB) virus genomes in two and three cases, respectively. Epstein-Barr virus may play a role in lymphomagenesis, although on relatively rare occasions.

A clinicopathologic study of 233 cases with special reference to evaluation with the MIB-1 index

BACKGROUND

Few articles have analyzed the prognostic data from a large series of primary gastric lymphoma classified according to the concept of mucosa-associated lymphoid tissue (MALT).

METHODS

The resected specimens from 233 patients with primary gastric lymphoma were investigated retrospectively, including immunostaining with MIB-1 (Ki-67).

RESULTS

Histologically, 70 (30%) of the cases were low grade B-cell lymphoma of MALT, 27 (12%) low grade B-cell lymphoma of MALT with a focal high grade component, 100 (43%) high grade B-cell lymphoma of MALT, 15 (6%) other B-cell lymphomas, 14 (6%) T-cell lymphomas, and 7 (3%) undetermined. Macroscopically, 96 (41%) were superficial-spreading type, 100 (43%) mass-forming, 14 (6%) diffuse-infiltrating, and 23 (10%) unclassified. The MIB-1 index correlated with phenotype, histologic grade, stage, depth of invasion, and macroscopic type. A significantly better survival was noted for young patients, and those with tumors of a B-cell phenotype, histologic low grade, macroscopic superficial-spreading type, low stage, low depth of invasion, and low MIB-1 index. No significantly different survival rates were found between the patients who underwent gastric resection alone and those who also received additional chemotherapy. By Cox multivariate analysis, independent prognosticators included B-cell phenotype, low stage, and macroscopic superficial-spreading type.

CONCLUSIONS

In addition to stage, phenotype and macroscopic type are also important prognostic indicators of primary gastric lymphoma. Immunostaining with MIB-1 had limited independent value for predicting prognosis.

Primary gastric CD30 (Ki-1)-positive large cell non-Hodgkin's lymphomas. A clinicopathologic analysis of six cases

BACKGROUND

The CD30/Ki-1 antigen characterizes a series of non-Hodgkin's lymphomas (NHL) predominantly showing anaplastic large cell (ALCL) morphology and frequently involving the skin and other extranodal sites. In cutaneous large cell lymphomas, the CD30 expression was indicated as a favorable prognostic marker independently from cytology, anaplastic versus nonanaplastic. The stomach is the most common site of extranodal lymphomas in the adult population, but primary gastric CD30+ lymphomas have been reported rarely.

METHODS

The clinical, morphologic, and immunohistochemical features of six cases with primary CD30/Ki-1+ gastric large cell lymphomas were analyzed.

RESULTS

The mean age of patients was 64 years with a prevalence of women (M:F ration = 1:2). Patients were assigned to Stage IE or IIE. Three of them died of disease, whereas the others are still alive (mean follow-up, 18 months). Three of six cases had ALCL morphology, whereas other cases had centroblastic, immunoblastic, and high-grade mucosa-associated lymphoid tissue lymphoma. Immunohistochemistry revealed a B-cell phenotype in three of six cases; a T-cell phenotype in one of six cases; and a null, non-B, non-T phenotype in two of six cases.

CONCLUSIONS

Within CD30+ primary gastric large cell lymphomas, cytology, anaplastic versus nonanaplastic, did not affect clinical presentation and/or prognosis. The survival rate of the patients studied is in keeping with literature reports regarding prognosis of primary high-grade gastric NHL. The findings suggest that clinical behavior of this extranodal lymphoma is more closely related to clinical symptoms and initial stage of disease than to CD30 expression.

Primary T-cell lymphoma of the gastrointestinal tract associated with human T-cell lymphotropic virus type I. An analysis using in situ hybridization and polymerase chain reaction

BACKGROUND

During a population-based local cancer registry, a peculiar type of T-cell lymphoma restricted to the gastrointestinal tract was found in patients living in southwestern Japan.

METHODS

Five cases of gastrointestinal (GI) tract T-cell lymphoma were analyzed with immunohistologic examination, ultrastructural analysis, in situ hybridization (ISH), and polymerase chain reaction (PCR).

RESULTS

All cases satisfied the criteria of primary GI tract lymphoma at presentation or operation. Four showed a close relationship to human T-cell lymphotropic virus type I (HTLV-I). Those four had positive results for anti-HTLV-I antibody and positive surface markers for CD4, positive hybridization signals by ISH, and HTLV-I gene products by PCR, but they had no lymphoma cells in peripheral blood or bone marrow. The fifth case showed negative signals by ISH and PCR.

CONCLUSIONS

These findings suggest that some of the putative adult T-cell leukemia/lymphoma (ATLL) types can be further classified as GI-tract-type lymphoma. The prognosis for the GI tract type is as poor as it is for conventional ATLL.

Malignant lymphomas of the upper gastrointestinal tract. Results of a prospective study in 103 patients

BACKGROUND

There is a discrepancy between the incidence of gastrointestinal involvement by malignant lymphomas, as established in postmortem studies, and the rareness of the corresponding clinical diagnosis.

METHODS

Therefore, the authors performed routine upper gastrointestinal endoscopic examination, within the framework of the usual staging examinations, in 103 consecutive patients with newly diagnosed Hodgkin disease (n = 21) and non-Hodgkin lymphoma (n = 82).

RESULTS

One patient with Hodgkin disease (4.8%), 11 of 40 patients (27.5%) with non-Hodgkin lymphoma of low-grade malignancy, and 11 of 42 (26.2%) of those with highly malignant non-Hodgkin lymphoma showed involvement of the gastric and/or duodenal mucosa, as diagnosed with esophagogastroduodenoscopy. Of the 22 patients with non-Hodgkin lymphoma, 9 had involvement of other mucosa-associated lymphoid or epithelial tissue. In two patients with Stage III, two with Stage II, and two patients with presumptive Stage I disease, the disease was reclassified as Stage IV. Because of gastrointestinal involvement, treatment for two patients was changed from radiation therapy to chemotherapy and another two patients had gastric resections so that possible treatment-related complications could be avoided.

CONCLUSIONS

In light of these results and the fact that a major basis for the therapeutic strategy for malignant lymphomas is tumor stage, routine esophagogastroduodenoscopic examination within the framework of the usual staging examinations is recommended. In individual cases, this procedure may be of decisive importance in the therapeutic approach to and prevention of complications.

Primary gastric T-cell lymphoma with manifold histologic appearances

A rare case of malignant T-cell lymphoma with manifold histologic appearances was described. The lymphoma occurred in the stomach of a 50-year-old Japanese male. Grossly, the lymphoma exhibited a deeply ulcerated mass. Histologically, in addition to diffuse infiltrate of large lymphoid cells with deeply indented nuclei, there were many epithelioid cell granulomas, remarkable tissue eosinophilia and stromal fibrosis, mimicking inflammatory disease. Immunohistochemical studies and a gene analysis demonstrated the T-cell phenotype.

Clinicopathologic study of large cell anaplastic lymphoma (Ki-1-positive large cell lymphoma) among the Japanese

The clinical, prognostic, phenotypic, and genotypic findings of 30 patients with large cell anaplastic lymphoma (Ki-1-positive large cell lymphoma) were analyzed. There were 13 male and 17 female patients (male-female ratio, 0.8) whose ages ranged from 3 to 81 years of age (mean, 28 years of age; 67% of the patients younger than 30 years of age). The 5-year survival rate was 52%; this was better than that of other types of high-grade peripheral T-cell lymphoma. Histologic examination showed distinctive morphologic features such as tumor cell pleomorphism, sinus infiltration, fibrosis, partial lymph node involvement, sparing of B-cell regions, and occasional plasma cell infiltrates. Eighty percent of the cases were of T-cell phenotype, and others expressed neither B-cell nor T-cell markers. The tumors were frequently positive for a histocompatibility antigen (HLA-DR), CD25 (the interleukin-2 receptor), and epithelial membrane antigen. Rearrangements of the T-cell receptor beta gene were observed in nine of 13 cases (69%). These findings indicated that many of the tumors had the phenotype and genotype of activated T-cells. This study also showed that large cell anaplastic lymphoma has a survival figure intermediate between Hodgkin's disease and low-grade peripheral T-cell lymphoma.

Long-term survival in Ki-1 lymphoma

Three patients with histologic and immunologic features of Ki-1-positive large cell lymphoma, who experienced long-term survival, are presented. These three patients at 2, 28, and 49 years of age had adenopathy; all cases had been initially misdiagnosed as metastatic carcinoma or malignant histiocytosis. On subsequent review, they had sinusal and diffuse growth of large pleomorphic cells that were Ber-H2 (Ki-1; CD 30) positive. One case marked as a T-cell lymphoma with UCHL1, one case expressed T-cell and B-cell markers, and one case was negative for both T-cell and B-cell markers. All patients received chemotherapy, and two received local radiation. One patient was not treated until 9 years after initial diagnosis. Two patients had several recurrences, but there has been no evidence of lymphoma in any of the three patients for 63 to 301 months; overall survival time has ranged from 14 to 25 years. These cases are the longest reported survivors with Ki-1 lymphoma; 5 years was the longest survival time previously reported. It also is noteworthy that Ber-H2 and other lymphoid-associated antigens appear to be preserved in formalin-fixed, paraffin-embedded tissues for prolonged periods. This may allow retrospective studies to evaluate the natural history of Ki-1 lymphomas, as well as their spontaneous or treatment-induced regression.

Primary gastric T-cell lymphoma of suppressor-cytotoxic (CD8+) phenotype: discordant expression of T-cell receptor subunit beta F1, CD7, and CD3 antigens

Primary gastric T-cell lymphomas are rare neoplasms, and all but one of the previously phenotyped cases have shown a helper-inducer phenotype. The present case is the second reported case of a primary gastric T-cell lymphoma of suppressor-cytotoxic phenotype. The tumor histology was similar to that described in some forms of node-based peripheral T-cell lymphomas. Phenotypic analysis revealed low expression of pan-T marker CD7, reduced expression of CD3, but higher density and frequency of expression of CD8 antigens that could be predicted on the basis of the pan-T markers. Natural killer cell (NK) related markers CD16, HNK-1 and NKH-1 were not expressed by the neoplastic cells. T-cell receptor (TCR) beta subunit expression was detected on fewer cells than would have been predicted on the basis of CD3 and CD8 expression, and TCR delta chain expression was undetectable.

Anaplastic large cell Ki-1 lymphoma. Delineation of two morphological types

This report describes 16 cases of the recently recognized anaplastic large cell Ki-1 lymphoma. The disease showed a male:female ratio of 2.2:1 and a bimodal age distribution with peaks in the third and eighth decades. The clinical presentation was highly variable, with lymph node, skin, bone and gastrointestinal tract being the most commonly affected sites. The lymph nodes usually showed subtotal or sinusoidal involvement, and parenchymal fibrosis was common. The large neoplastic cells were almost invariably admixed with many reactive small lymphocytes, histiocytes and/or neutrophils. Two cytological types could be delineated: type I (pale cell, four cases) consisted of large polygonal cells with distinct pink-staining cell membrane and pale cytoplasm and pleomorphic nuclei showing marked chromatin clearing; and type II (basophilic cell, 12 cases) consisted of round or oval cells with basophilic cytoplasm and/or paranuclear pale hof, pleomorphic nuclei often reniform or lobulated and with frequent multinucleated wreath-like and Reed-Sternberg-like cells. Immunohistochemical studies showed that nine cases (56.3%) exhibited a T-cell phenotype, three cases (18.8%) each exhibited a B-cell or null-cell phenotype, while one case exhibited both T- and B-cell markers. Cutaneous involvement at presentation was associated with a favourable outcome, and spontaneous regression was common. For patients with non-cutaneous presentation, the prognosis was relatively good for young patients treated with aggressive chemotherapy, but was grave for old patients.