title: T-cell lymphomas of the stomach: morphological and immunological studies characterizing two cases of T-cell lymphoma.
abstract: Using cytochemical, electron microscopic and immunohistochemical techniques in 20 primary malignant lymphomas of the stomach, we found 18 B-cell and 2 T-cell lymphomas. Primary T-cell lymphoma in the stomach has not been previously reported. The T cells in both cases were reminiscent of T immunoblasts with prominent nucleoli and a basophilic cytoplasm. Case 1 showed a cytological relationship to pleomorphic T-cell lymphoma, large cell type. Case 2 contained in addition some cells not previously described in T-cell lymphomas, resembling immature plasma cells with abundant rough endoplasmic reticulum. Focal positivity to acid phosphatase and dipeptidylaminopeptidase IV suggests the T-cell nature of both lymphomas. In both cases the tumour cells were OKT 11 and OKT 4 positive, and negative for OKT 8. Thus, both cases represent high-grade malignant T-cell lymphomas which correspond phenotypically to T-helper cell lymphoma. Case 2 revealed a further immunohistochemical peculiarity: atypical immunoblasts reacted positively with Ki-1 antibody. Thus, it is a Ki-1 lymphoma of T-cell type.
mesh_terms: D000293:Adolescent; D000368:Aged; D000954:Antigens, Surface / Q000032:analysis; D018819:Dipeptidyl Peptidase 4; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000032:analysis; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D008223:Lymphoma / Q000276:immunology / Q000473:pathology* / Q000648:ultrastructure; D008297:Male; D013274:Stomach Neoplasms / Q000276:immunology / Q000473:pathology* / Q000648:ultrastructure; D013601:T-Lymphocytes
chemical_list: D000954:Antigens, Surface; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D018819:Dipeptidyl Peptidase 4