Occurrence of monocytoid B lymphocytes in lymph nodes of patients treated by chemotherapy

Occurrence of monocytoi B lymphocytes (MBL) in the lymph nodes of patients receiving preoperative chemotherapy for cancer was examined and compared to lymph nodes in controls who had not received chemotherapy. Number of patients receiving and not receiving preoperative chemotherapy were 3 and 10 cases in ovarian cancer, 7 and 11 in testicular cancer, and 22 and 8 in lung cancer, respectively. Chemotherapeutic agents for ovarian, testicular, and lung cancer consisted of cisplatin, Adriamycin, and cyclophosphamide; cisplatin, vinblastine, and bleomycin; and cisplatin, vindesin, and mitomycin, respectively. MBL were defined morphologically as having abundant pale cytoplasm with distinct cell borders and small nucleus. Immunohistochemistry revealed a B-cell nature of these cells, i.e., CD20+ and/or MB-1+ together with negative reactivity for antibodies for T lymphocytes (CD43, CD45RO, OPD4) and macrophages (KP-1, PGM-1). Monocytoid cells in two cases showed a positive reactivity for CD43 together with CD20. The occurrence rate of MBL in patients with ovarian, lung, and testicular cancer receiving and not receiving chemotherapy was 67% (2/3) and 10% (1/10), 59% (13/22) and 75% (6/8), and 43% (3/7) and 9% (1/11), respectively. The occurrence rate in the total patients receiving chemotherapy (56%) was significantly higher than for those not receiving chemotherapy (28%) (P < 0.05). These findings suggest that chemotherapy-induced depressed immune function is causative for the occurrence of MBL in the lymph nodes. MBL might be found more frequently in nodes from patients who have received chemotherapy in certain settings.

Splenic marginal zone lymphoma. A distinct B-cell neoplasm

The splenic marginal zone is a morphologically and perhaps immunologically distinct B-cell compartment. Lymphomas arising from cells of the splenic marginal zone are rare. Here we describe the morphologic, immunologic, and clinical features of 14 cases. Patient age ranged from 35 to 79 years (median, 68 years) with a male-to-female ratio of 1:1.8. The spleen was uniformly enlarged (median, 1,540 g; range, 388-3,845 g) in all patients, the neoplastic infiltrate had a nodular pattern in three cases, nodular and diffuse in seven cases, and diffuse in four cases. The neoplastic cells had small to medium-sized nuclei with round, oval, or slightly indented contours, small eosinophilic nucleoli, and a moderate amount of pale cytoplasm. Extrasplenic involvement was present in 12 patients. Lymph nodes often had a vaguely nodular pattern and preservation of sinuses; bone marrow was infiltrated focally (seven cases) or diffusely (one case). Five patients had hepatic involvement. Ultrastructurally, neoplastic cells differed from other small B cells and resembled normal marginal zone cells by having long, serpentine rough endoplasmic reticulum profiles. All lymphomas marked as B cells and light chain restriction was demonstrated in 12 cases. Bcl-2 protein expression was present in all cases. Most cases (70%) were negative for DBA.44 (CD72). Plasmacytic differentiation was present in three cases. In conclusion, splenic marginal zone lymphoma is a B-cell neoplasm with distinctive clinical, morphologic, immunologic, and ultrastructural characteristics.

Splenic marginal zone lymphocytes and related cells in the lymph node: a morphologic and immunohistochemical study

The marginal zone of the spleen contains a well-defined population of lymphocytes with an unknown function. The question is whether this cell population is unique to the spleen or is it also present in the lymph node. These cells have medium-sized nuclei and a moderate amount of cytoplasm. Immunohistochemistry and enzyme histochemistry revealed a marker pattern by which these cells could be distinguished from the lymphocytes of the mantle zone of the spleen: IgD-, CD23-, KiB3-, and alkaline phosphatase+. In the lymph node, the outer side of the follicular mantle contains a subpopulation of B lymphocytes with a similar morphology and the same marker pattern. This subpopulation differs from the marginal zone cells in the spleen in that it does not form a distinct zone. These cells are especially prominent in lymph nodes with fatty atrophy. Their relationship to other subpopulations of B lymphocytes and to malignant lymphomas is evaluated but remains questionable.