Ultrastructural studies of type II fucosidosis.

Type II fucosidosis in an autosomal recessive disease. The paper presents a case of a patient with alpha-L-fucosidase of whom a skin specimen was examined under the electron microscope. Storage material was observed mainly in endothelial cells of blood capillaries and Schwann cells surrounding small peripheral nerves of papillary dermis. Within both cells two different kinds of inclusions were revealed: (1) clear vacuoles and (2) dense bodies with an internal structure prevalently lamellar. All these ultrastructural alterations were observed long before the appearance of clinically defined angiokeratoma at cutaneous level. Hence, they present the same alteration found in the absence of angiokeratoma in type I fucosidosis.

Urbach-Wiethe disease. Light and electron microscopic study.

A case of lipoid proteinosis was subjected to clinical, histologic and electron microscopic study. Palpebral biopsies showed a large dermal infiltration composed of closely interwoven granulo-filamentous material in the superficial and deep dermis. Collagen fibers were normal. Fibroblasts seemed to play an active role in the synthesis of this accumulating substance. Around the dermal capillaries there was a prominent concentric multilamination of the basal lamina which was considered a reaction of the endothelial cells to the irritation caused by compression of the accumulating substance.

[Presence of clusters of Langerhans cells and lymphoid cells in the peritumoral infiltrate of a case of basal cell naevus syndrome. Ultrastructural study (author's transl)]. / Sur la présence d'agrégats constitués de cellules de Langerhans et cellules lymphoïdes dans l'infiltrat péri-tumoral dans un cas de naevomatose baso-cellulaire. Etude ultrastructurale.

A case of naevoid basal cell carcinoma syndrome with clusters of Langerhans' and lymphoid cells in the inflammatory peritumoral infiltrate, is reported. Electron microscopy shows intercellular contacts between eight to ten lymphoid cells and a single Langerhans' cell. These contacts occur over limited areas of the cell membranes by means of zones of high electron density on the outer edge of the cytoplasm. The functional significance of this finding is discussed, bearing in mind that recent observations have established certain analogies between Langerhans' and interdigitating reticulum cells. The latter might, within the thymus-dependent region of the lymph nodes, contribute to the formation of a micro-environment favourable to certain immunological activities of T-lymphocyte populations.