Eosinophilic granuloma of the bone in Hand-Schüller-Christian disease: extensive in vivo eosinophil degranulation and subsequent binding of released eosinophil peroxidase (EPO) to other inflammatory cells.

The eosinophils from bone granuloma, bone marrow, and peripheral blood of a patient with Hand-Schüller-Christian disease (HSCD) were studied by electron microscopy and cytochemistry. Impressive eosinophil degranulation was observed. Extracellular release of eosinophil peroxidase (EPO) and EPO binding to surrounding cells were seen in the granuloma and bone marrow. Cells with peroxidase-positive plasma membrane were also observed in peripheral blood. The pattern of eosinophil degranulation showed quite different features from those described so far. In the granuloma, the process begins with intracytoplasmic release of the granule matrix content, as revealed by both extensive extragranular accumulation of EPO and progressive decrease of the matrix electron density. Core dissolution follows thereafter, leading to complete disappearance of the granules. At the end of the process, the cells show rupture of the plasma membrane and release of their content into the surrounding environment. This pattern of secretion was also observed in blood and marrow eosinophils of the patient. In view of the previously reported findings that EPO binding to inflammatory cells influences their functions, EPO release and binding to surrounding cells in HSCD may play a role in the evolution of the inflammatory lesion in the disease.

Langerhans' cells and macrophages in eosinophilic granuloma. An enzyme-histochemical, enzyme-cytochemical, and ultrastructural study.

Biopsy material of six patients with eosinophilic granuloma (EG) was investigated by electron microscopic and enzyme-histochemical methods for acid phosphatase (AcP), leucyl-beta-naphthylamidase (LA), adenosine triphosphatase, and alpha-naphthyl-acetate esterase (NE). Paraplast sections were used for demonstration of lysozyme with an immunoperoxidase method. Results of staining for these different enzymes suggested the existence of two separate sets of histiocytic cells: one type with "dot-like" AcP staining and negative for NE and lysozyme; and the other with diffuse AcP staining, positive for NE and lysozyme, and often showing signs of phagocytosis. The first type presumably represented Langerhans' cells and also often showed positive staining for LA. Macrophages were generally negative for LA. Electron microscopic study confirmed the impression gained from enzyme-histochemical studies. No intermediate cell types between Langerhans' cells and genuine macrophages were seen. From these results it is concluded that in EG no transformation exists between Langerhans' cells and macrophages. The latter are presumably of reactive nature.

Primary eosinophilic granuloma of the frontal lobe.

The clinical symptoms, pathological findings and surgical treatment of a case of primary frontal lobe eosinophilic granuloma are presented. Initially a frontal mass was detected that clinically seemed like a low-growth tumor. After operation, the histological, cytochemical and ultrastructural studies showed positive acid phosphatase, alpha-naftil-esterase, oil-red and PAS reactions of tumoral cells and the presence of rod-shaped bodies in proliferative histiocytes, all which confirmed the pathological diagnosis of eosinophilic granuloma. Other osseous or visceral histiocytosis-X signs were not observed. The patient remains asymptomatic after a postoperative follow-up of 2 years.

alpha-D-mannosidase activity in histiocytosis X.

A histochemical study of enzymatic activities was undertaken in five cases of histiocytosis X (two localized bone forms, two generalized forms, and one involving mainly the skin), each of which revealed characteristic structural features at the optical and ultrastructural levels. A confirmation was made of the original assumption of high acid alpha-D-mannosidase activity, i.e. activity described in human Langerhans intraepidermal cells (Elleder, 1975). In the control group of tumors, with the exception of urticaria pigmentosa, enzyme activity was either at trace level or altogether absent. Acid alpha-D-mannosidase activity therefore appears to be the first biochemical feature common to both histiocytosis X and the Langerhans cells. The significance of the finding for the present theory of the histogenesis of the above tumors is discussed.