Kenji Miyake

Increased Incidence of Follicular Lymphoma in the Duodenum

The incidence of indolent lymphomas in the lymph nodes and extranodal regions is quite different. Follicular lymphoma (FL) is most common in the nodes, and it seems to be least common in the gastrointestinal (GI) tract, where mucosa-associated lymphoid tissue lymphoma arises most frequently. The authors report that the incidence of FL is unexpectedly high in the duodenum compared with other portions of the GI tract. FL was detected in only eight of 222 cases of GI lymphoma (3.6%). However, five cases of FL arose in the duodenum, which accounted for 38.5% of 13 duodenal lymphomas. Only in two patients did FL arise in either the stomach or the colorectum, and in the remaining patients FL was widespread with lymphomatous polyposis. Duodenal FL was composed of neoplastic follicles with small cleaved cells in dominance, and the immunophenotype of the lymphoma cells was CD10+, BCL-2+, CD20+, CD75+, CD79+, CD3-, CD5-, cyclin D1-, CD23-, and CD45RO-. All the patients were women age 37 to 66 years (average age, 52.4 yrs). In all patients the lymphoma was present around the ampulla of Vater, and four of five patients showed multiple small-size polyps. Although lymphoma cell infiltration was confined to the submucosa in the four patients examined, the regional lymph nodes were involved partially in two patients without distant metastasis. All patients are alive at 2 to 50 months of follow up (average, 27 mos), which is comparable with the prognosis for indolent nodal lymphomas. These results suggest that the duodenum has a distinct background of histogenesis of the lymphomas and that biopsy specimens from the duodenum with multiple polyps should be examined carefully.

Abnormal expression of the human CD44 gene in early colorectal malignancy with special reference to variant exon 9 (9v).

AIMS: To examine the expression of CD44 variant exon 9 in early colorectal malignancies. METHODS: Formalin fixed, paraffin wax embedded tissue sections from 30 cases of tubular adenoma and 35 cases of adenoma with focal carcinoma of the colon were examined immunohistochemically using a monoclonal antibody (MAb 11.24) directed against CD44-9v. RESULTS: In the normal colorectal mucosa immunoreactivity was confined to the basal part of the crypts and was expressed in less than 10% of crypt cells. CD44-9v was expressed in the superficial part of tubular adenoma with mild atypia in 67% of the cases and in 19% of the tumour cells. The immunoreactivity was observed along the basement membrane in mild atypia, as in the non-neoplastic crypts. In the course of progression to severe atypia the spatial polarity of immunoreactivity was lost, and the extent of CD44-9v expression increased in intensity and in the percentage of positive cases and positive cells. In the carcinomatous lesions of adenoma with focal carcinoma, 94% of the cases and 44% of the tumour cells were positive for CD44-9v protein. CONCLUSION: CD44-9v may be overexpressed at the early stage of colorectal tumorigenesis and this increase continues throughout the course of the disease.

CD30 antigen in non‐Hodgkin's lymphoma

Expression of the CD30 antigen in lymphoid neoplasms and reactive lesions were examined immunohistologically using the monoclonal antibody BerH2. CD30 antigen was expressed in 17 of 18 patients with Hodgkins disease (HD), all of three anaplastic large cell lymphomas (ALCL), 11 of 52 T‐cell malignant lymphomas (TML) including ALCL, 13 of 153 B‐cell malignant lymphomas (BML) including ALCL, two of three malignant histiocytosis and one of four plasmacytomas, Although a single case of small cell lymphoma was positive, in cases of mixed cellular morphology, neoplastic cells of larger or more pleomorphic nuclei tended to be stained more extensively and intensively. This antigen is expressed in TML significantly more often than in BML (P 0.05). CD30 antigen was expressed less frequently at clinical stage I than those of stages II to IV. There was no significant relationship between CD30 antigen expression and that of proliferating cell nuclear antigen or CD43 antigen in non‐Hodgkins lymphomas (NHL). The CD30 antigen expression did not affect the prognosis of NHL overall, but in high grade TML, CD30 antigen‐positive individuals tended to have a more favorable prognosis than those that were negative. In reactive diseases, some plasma cells, immunoblasts, interdigitating cells, follicular center cells and histiocytes were stained positively, but not always, and with variable intensity. These results suggest that CD30 antigen is expressed In various cell lineages to some extent and may relate to cellular activation in some instances. When making the histopathologic diagnosis of HO or NHL including ALCL, CD30‐positive cell should be carefully interpreted. The authors believe that the name‘Ki‐1 lymphoma’or‘KM positive lymphoma’as a synonym of ALCL should therefore be abandoned.

An immunohistochemical study on HLA-DR expression in human meningiomas

SummaryThe expression of HLA-DR was examined in 38 cases of meningiomas with the streptavidin-biotin immunoperoxidase method using two monoclonal antibodies to HLA-DR (LN-3 and TAL-IB5) on formalinfixed, paraffin-embedded specimens. Similar immunoreactivity was obtained with these two monoclonal antibodies. In addition to infiltrated lymphoid cells and perivascular macrophages, tumor cells themselves showed HLA-DR expression in 16 cases (42%) of meningiomas. The rate of HLA-DR-positive cases in the transitional and fibrous subtypes (64% and 67%, respectively) was higher than that in the meningotheliomatous subtype (8%). Spindle-shaped tumor cells were frequently positive for HLA-DR, whereas few of meningotheliomatous cells with plump cytoplasm were positive. Most of HLA-DR-positive cases showed no or scanty lymphoid cell infiltration, and a few cases with marked infiltration of lymphoid cells were variable for HLA-DR expression. These findings suggest little correlation between HLA-DR expression of tumor cells and the degree of lymphoid cell infiltration, but indicate an aberrant HLA-DR expression of tumor cells themselves.