Peanut agglutinin binding as a histochemical tool for diagnosis of eosinophilic granuloma.

Histochemical detection of peanut agglutinin binding performed on tissue sections in 11 cases of eosinophilic granuloma of bone revealed simultaneous appearance of the reaction product both at the cell surface and within the cytoplasm (in the Golgi area) of a vast majority of Langerhans' cells. Based on this unique characteristic of Langerhans' cells, peanut agglutinin binding assay may represent a simple and inexpensive tool for morphologic differentiation of eosinophilic granuloma or other types of histiocytosis X from other monocytic and histiocytic lesions in equivocal cases.