Ultrastruktur und Pathogenese der BCG-Histiocytose (sog. BCG-Granulomatose)

Bacterial lymphadenitis with the picture of a lymphoepithelioid cell lymphoma--Lennert's lymphoma

Three cases with the typical light microscopic picture of lymphoepithelioid cell lymphoma (so-called Lennert's lymphoma) were investigated by electron microscopy. Surprisingly, Lennert's lymphoma could be excluded in two cases. These two cases exhibited, in addition to pleomorphic lymphocytes and epithelioid cells, macrophages with accumulations of bacteria, indicating that a bacterial infection was the cause of the disease. By comparing the typical case of Lennert's lymphoma with the other cases, we found several criteria for distinguishing between Lennert's lymphoma and bacterial lymphadenitis. In bacterial lymphadenitis: (1) small and medium-sized lymphocytes exhibited a wide cytological spectrum whereas the lymphocytes in Lennert's lymphoma were relatively uniform; the lymphocytes with prominent lysosome-like granules found in Lennert's lymphoma were not seen; (2) cytology and distribution of epithelioid cells were similar to those in Lennert's lymphoma; (3) epithelioid venules contained recirculating lymphocytes, which were rarely found in Lennert's lymphoma; (4) numerous interdigitating reticulum cells, fibroblasts and myofibroblasts were seen, but not in Lennert's lymphoma; (5) focal increase in reticulin fibres was the main difference in light microscopy; (6) rod-shaped bacteria were accumulated in the cytoplasm of a few macrophages. The presence of bacteria could not be demonstrated unequivocally by light microscopy. In both cases the large number of intracytoplasmic bacteria suggests that this unusual and until now unknown lymphadenitis is the result of an infection caused by facultative intracellular parasitic bacteria. The outcome of bacterial lymphadenitis that gives the false impression of Lennert's lymphoma is uncertain. Cure was achieved in one of our cases. The other patient died before therapy was commenced.

Modulation of epithelioid cell granuloma formation to apathogenic mycobacteria by cyclosporin A

Epithelioid cell granuloma (ECG) formation after subcutaneous injection of different strains of mycobacteria has been followed by light and electron microscopy. EC granulomas are found at 2 weeks after injection at the local site and in the regional lymph nodes. The cellular composition of the inflammatory exudate as well as the reaction pattern of the lymphoid tissue showed characteristic time dependent changes. Infection with various strains of mycobacteria, however, did not reveal significant differences with respect to ECG formation. Treatment with cyclosporin A (CS-A) prevented the formation of ECG and the development of caseating necrosis. Macrophages accumulated at the local site and in the regional lymph node and contained numerous mostly well-preserved mycobacteria. No generalization of the infection was found, however. These results strongly suggest that ECG formation in vivo is 1) a T lymphocyte dependent phenomenon and 2) that inhibition of T lymphocyte activation by CS-A prevented also harmful effects of the mycobacterial infection in our model. The relevance of these results with respect to granulomatous diseases are discussed.

Disseminated mycobacterial histiocytosis due to M. Fortuitum associated with helper T-lymphocyte immune deficiency

Mycobacterial histiocytosis is a rare disease usually associated with haematological or immunological disorders. We report a fatal case caused by M. fortuitum infection showing the typical disseminated histiocytosis. Immunological investigations revealed impaired cellular immunity demonstrated by negative skin tests with different "recall-antigens", and in vitro an isolated defect of helper T-lymphocytes in the peripheral blood which in combination with hypergammaglobulinemia suggests a "lymphocyte and distribution syndrome".

The ultrastructure of mycobacterium marinum granuloma in man

3 biopsies of 3-5 week-old nodular lesions in 2 patients with so-called swimming-pool (aquarium-) granuloma have been examined by electron microscopy. The cytohistological spectrum simultaneously comprises acute exudative as well as chronic proliferative phenomena. Epithelioid cells and collagen producing fibroblasts are already conspicious in 3 week-old granuloma. According to the cytological composition the Mycobacterium marinum granuloma represents a high-turnover granuloma with immunogenic origin. It is comparable to mycobacterial diseases in the presence of well developed cell mediated immunity (Lupus vulgaris, tuberculoid leprosy). Degrading mycobacteria have been rarely detected in phagocytes and are compared with viable bacilli in macrophages of experimentally infected mice. Curved and annular parallel membranes ("worm-like structures") in the cytoplasm of transformed macrophages and in fibroblasts presumably originate from the membranes of endoplasmic reticulum. Cord-like structures with transverse bands (periodicity 170-180 A) in the lumen of RER of some fibroblasts are interpreted as intracellularly aggregated collagen precursors.

[Generalized familial semibenign BCG infection, salmonella osteomyelitis and intestinal pseudotuberculosis--due to a familial defect of the macrophage system? (author's transl)]

Two siblings became very ill after BCG inoculation in the newborn period. A generalized BCG infection was assumed from the clinical symptomatology and the histological findings. Later on the boy suffered from enteric salmonellosis and osteomyelitis caused by the same organism, and as a todler he had intestinal pseudotuberculosis. Prompt recovery took place under selective antibiotic therapy. No known immunodeficiency disease could be correlated with this familial syndrome of increased susceptibility to intracellular vital microbes. A defective function of the patients macrophage system is suspected.

Sinus histiocytosis with massive lymphadenopathy: fifteen new cases

Fifteen cases of chronic lymphadenitis with massive hemophagocytic sinus histiocytosis were analyzed. Fourteen patients were whites, 13 were Europeans, and 11 were males; 10 patients were under 10, 4 were over 20, and 2 over 60 years old. The oldest patient died; all other either healed without therapy or are in excellent condition. We studied the cytologic features of lymph node imprints. A 5-year-old girl was examined more thoroughly. High antibody titers to Klebsiella antigens were found repeatedly. The patient also had a constant lymphocytopenia. Phytohemagglutinin-induced blast transformation and lymphotoxin production were within normal limits. No serum Epstein-Barr virus-antibodies could be detected.