Langerhans cells (LCs) and interdigitating cells (IDCs) are said to have the same morphological and immunological characteristics. We have reported on Birbeck granules (BG)-bearing LCs, which are positive for both OKT-6 (CD1a) and anti S-100 protein antibodies, and IDCs which are only positive for S-100 protein, but negative for OKT-6. In this paper, we examined the characteristics of dendritic cells in dermatopathic lymphadenopathy (DPL) and Histiocytosis X (HCX) using immunohistochemical and immuno-electron microscopic techniques. The majority of the dendritic cells which existed in the lymph nodes of DPL were positive for OKT-6. We concluded that these dendritic cells were not IDCs, but LCs. Electron microscopically, LCs in these lymph nodes contained only a few BG. Most of the LCs were negative for PCNA antibody. This finding means that the proliferative activity of these LCs is very low and that they do not divide or proliferate in the lymph nodes. On the other hand, HCX is considered to be a rare proliferative disorder of LCs. HCX cells were positive for S-100, OKT-6, CD4 (Leu3a) and HLA-DR (Ia), in addition they were highly positivity for PCNA. These findings indicate that HCX cells originate in immature cells which are already part of the Langerhans cell lineage.

View full abstract

The Tf-r-positive rate with AML, both at onset and reccurrence, was 25.5±17.2% which was lower than that of normal. On remission, the positive rate was restored to the level of healthy subjects. The Tf-r-positive rate with CMMoL was 9.0±1.4%, considerably lower than the normal.
The results suggest that in AML at onset and recurrence, and in CMMoL, differentiation of monocytes to macrophages may be suppressed, or the monocytes belong to a sub-group with low appearance of Tf-r.

View full abstract

A 41-year-old woman was admitted because of severe anemia (Hb 6.1g/dl). She had a systemic lymphadenopathy but no hepatosplenomegaly. The anemia was normocytic and was accompanied by reticulocytopenia (0‰) and the platelet count was normal, and many abnormal lymphoid cells were seen in the peripheral blood. The bone marrow aspirate revealed massive invasion of abnormal lymphoid cells and extreme erythroid hypoplasia (erythroblasts 1.5%). These abnormal cells were positive for Sm IgG, Sm IgD, Smλ, CD19, CD20 and CD5, but negative for Sm IgM, Sm IgA, Smκ and CD10. IgG-λ M-protein was detected in the serum. A pathologic diagnosis of “Malignant lymphoma, diffuse, medium sized cell type” was made by the lymph node biopsy. After three courses of CHOP-therapy, the lymph nodes decreased and the lymphoma cells disappeared from the blood, but her anemia with reticulocytopenia persisted. At this time the counts of granulocytes and megakaryocytes of the bone marrow were normal, but erythroid hypoplasia still continued (erythroblasts 6.8%). Shortly thereafter, however, a marked reticulocytosis occurred suddenly and then the anemia improved rapidly. Eight months later the lymphoma relapsed and many lymphoma cells reappeared in the bone marrow, but pure red cell aplasia (PRCA) did not recur. Although the pathogenesis of PRCA is unknown, this case indicates that not only B-CLL but also CD5-positive B cell lymphoma is accompanied by PRCA.

View full abstract

A 74-year-old male, who had been treated with artificial pneumothorax for pulmonary tuberculosis 38 years before, was admitted with fever on May 1992. Chest X-ray revealed the presence of scarred empyema in the right thorax, whereas the abdominal computed tomography indicated the presence of tumor extending from the pleural wall to the liver. The aspirated pleural effusion was suggestive of malignant lymphoma. He died in september 1992. Autopsy revealed non-Hodgkin's malignant lymphoma of pleural origin involving lower half of right pleura, right diaphragm and right upper abdominal cavity including the right lobe of the liver. Histologically was diffuse large cell type non-Hodgkin's lymphoma according to the LSG classification, showing B cell phenotype on immunohistologic studies. In addition, Epstein-Barr virus (EBV) genome, EBERs, EBNA2 (strong) and LMP (weak) proteins were detected by PCR, in situ hybridization and immunology, respectively, indicating the association of EBV with lymphomagenesis in this case.

View full abstract

Endothelial cells of the splenic sinuses in idiopathic portal hypertension (IPH) were immunohistochemically studied. The spleens obtained from 7 patients with IPH, 11 patients with liver cirrhosis, and 5 controls (3 with gastric cancer, 1 esophageal cancer and 1 gastric leiomyosarcoma) were examined.
In all cases with IPH, liver cirrhosis and the others, endothelial cells of splenic sinuses were positive for vimentin, factor VIII, and UEA-1. Cathepsin D and CD8 were also expressed in endothelial cells of the sinuses in IPH, liver cirrhosis and control spleens, although being negative in the endothelial cells of other vessels. HLA-DR was positive in the sinus endothelial cells in 6 of 7 patients with IPH, and it was expressed diffusely in 2 patients. In patients with liver cirrhosis and controls, HLA-DR was partly positive in 4 of 11 patients with liver cirrhosis and 3 of 5 controls. In IPH, increased expression of HLA-DR in the sinus endothelial cells was considered to represent the functioning as an antigen-presenting cell.
The PCNA-labeling index of sinus endothelial cells correlated with the areal ratio of the red pulp in IPH. It is suggested that, in IPH, the red pulp was increased by proliferation of the sinus endothelial cells. Expression of HLA-DR in sinus endothelial cells also increased in the spleens in which the PCNA-labeling index of endothelial cells of sinuses was high.

View full abstract