Tetsuji Mitsui

Neuroendocrine carcinoma (trabecular carcinoma) of the skin with ectopic ACTH production.

A case of ACTH‐producing cutaneous neuroendocrine carcinoma occurring in the cheek of an 80‐year‐old woman is reported. The tumor was composed of undifferentiated cells which had a uniform round nucleus and scanty cytoplasm containing argyrophil granules. An ultrastructural study demonstrated neurosecretory‐type granules in the cytoplasm of the tumor cells. Radioimmunoassay revealed an elevated level of ACTH in the tumor tissue as well as in the plasma of the patient. This is believed to be the first documented case of ACTH‐producing neuroendocrine carcinoma (trabecular carcinoma) of the skin.

HISTIOCYTIC NECROTIZING LYMPHADENITIS

The lymph nodes from 10 cases of histiocytic necrotizing lymphadenitis (HNL), 3 cases of necrotizing lymphadenitis with follicular hyperplasia (NLFH), and 11 cases of various types of lymphadenitis (abscess‐forming, tuberculous, Piringer‐type, “viral”, and nonspecific lymphadenitides) were comparatively studied. The NLFH, clinically representing a milder form of collagen disease, showed necrotizing lesions similar to those of HNL but with follicular hyperplasia, more plasma cells, and scattered neutrophils; the latter features closely resemble those of some lymph nodes in systemic lupus erythematosus (SLE). Ultrastructurally, HNL and NLFH both showed coagul‐ative necroses of individual lymphocytes, the macrophages with large cellular debris, prominent immunoblasts, and cytoplasmic inclusions such as frequent tubuloreticular structures (TRS) and “intracytoplasmic rodlets” (ICR). The necrotic modality in abscess‐forming and tuberculous lymphadenitides was different and the macrophages contained smaller debris. The immunoblasts were less prominent in “viral” lymphadenitis and much less in the others. While TRS were present in may cases of other lymphadenitides as well, they were positive in a much smaller number of cells only; the ICR were found exclusively in HNL and NLFH. These findings suggest a relationship between HNL and NLFH; they may form a spectrum of hyperimmune reaction that includes fSLE as an extreme manifestation.

Immunohistological study of histiocytic necrotizing lymphadenitis

Immunohistological study of 18 cases of histiocytic necrotizing lymphadenitis (HNL) demonstrated numerous helper/inducer cells (OKT-4) and suppressor/cytotoxic cells (OKT-8) with activation (Tac) and proliferation (OKT-9) markers, and histiocytes (lysozyme, α-1 antichymotrypsin, OK-M1) in the affected areas. However, B cells (B-1), NK cells (Leu-7 and Leu-11), complement proteins and receptor (C4 and C3d receptor), and neutrophils (chloroacetate esterase) were scanty or absent in these foci. Activity of NK cells was also decreased in the peripheral blood of 2 cases examined. The results suggest that HNL might be induced by the abnormal T cell-histiocyte response against some causative agents which induce a similar reaction of delayed hypersensitivity type.

Ultrastructure of adult T-cell leukemia/lymphoma.

SummaryEighteen cases of adult T-cell leukemia/lymphoma (ATLL) in Japan were analyzed by electron microscopy and compared with 5 cases of B-lymphoma and well-established groups of T-lymphomas (4 cases of T-lymphoblastic lymphoma and 2 cases of Sézary syndrome). Five hundred cells in each case, categorized ultrastructurally as to the cellular size and nuclear shape, showed an essentially pleomorphic cellular distribution in ATLL in remarkable contrast with the monomorphism of B-“histiocytic”, B-well-differentiated lymphocytic, and T-lymphoblastic lymphomas. Some B-lymphomas and Sézary syndrome also showed pleomorphism. Cases of ATLL were classified according to the predominant cells and degree of nuclear irregularity, which delineated a spectrum of node-based, peripheral T-cell neoplasms probably encompassing T-immunoblastic sarcoma, T-zone lymphoma, as well as multilobated T-cell lymphoma. The characteristic fine structure of ATLL, in comparison with that of B-lymphomas, included slight to marked nuclear irregularity with convoluted-shape predominance, a speckled chromatin pattern of the large cells, prominent lysosomes, and glycogen accumulation in addition to the difference in cellular distribution. Although T-lymphoblastic lymphoma and Sézary syndrome shared some of these features, the ultrastructural differentiation of ATLL from them seems to be possible.

Heterogeneity of Epithelial Cells and Reactive Components in Thymomas: An Ultrastructural and Immunohistochemical Study

Fourteen thymomas were studied by electron microscopy and immunohistochemistry. Based on the ultrastructure of the neoplastic epithelial cells in comparison with normal thymic epithelium, four cortical-, three mixed-, five medullary-, and two corpuscular-type tumors were categorized. Histologically the tumors of cortical type showed prominent lymphocytic infiltration, but scant interdigitating reticulum cells (IDCs) were demonstrated by immunoperoxidase method on paraffin sections with anti-S-100 protein antiserum. Fewer lymphocytes but more IDCs were present in the tumors of medullary and corpuscular types, although variable in those of mixed type. This corticomedullary difference among thymomas was confirmed in some of them by the immunoperoxidase method on frozen sections with monoclonal antibodies. The cortical-type tumors were HLA-DR positive in tumor cells and infiltrated predominantly with cortical thymocytes (OKT-6+, OKT-3-, both Leu 3a/3b+ and OKT-8+), whereas the medullary- and corpuscular-type tumors were HLA-DR positive primarily in IDCs but not in tumor cells and were infiltrated more with medullary thymocytes (OKT-6-, OKT-3+, either Leu 3a/3b+ or OKT-8+). The classification of thymomas based on neoplastic epithelial cells will serve to refine the traditional classification based on reactive lymphocytes.

NON‐HODGKIN'S LYMPHOMA IN NORTHWESTERN KYUSHU ISLAND OF JAPAN

Ninety cases of node‐based non‐Hodgkins lymphoma in northwestern Kyushu, Japan were classified according to the Japanese Lymphoma Study Group (LSG) and the immunological as well as clinicopathological studies were performed. There were 6 cases of small cell type, 23 of medium‐sized cell type, 25 of large cell type, 20 of pleomorphic type, 10 of lymphoblastic type and 6 cases of specific lymphomatous lesions (Lennerts lymphoma and T‐cell lymphoma with angioimmunoblastic lymphadenopathy‐Iike pattern). Immunologically, the T‐cell character was predominant in pleomorphic type (100%), specific lymphomatous lesions (100%), medium‐sized cell type (80%) and large cell type (60%). Clinically, leukemic manifestation was frequently encountered in all histological types except for large cell type. The leukemic cells in pleomorphic type and T‐medium‐sized cell type were polymorphic, similar to those of adult T‐cell leukemia. Skin lesions were found chiefly in leukemic cases of pleomorphic and T‐medium‐sized cell types, and non‐leuke‐mic cases of T‐large cell type. The worst prognosis was observed in the pleomorphic type, especially of leukemic form. These results support the proposal of pleomorphic type as a distinct entity in prospecting the immunological subtype, clinical manifestations, and survival. In addition, T‐medium‐sized cell and pleomorphic types, having common clinicopathological characteristics, may be categorized as one group. On the other hand, T‐large cell type seems to be composed of heterogenous groups of the peripheral T‐cell tumor, although some cases overlap with pleomorphic type.