Histoid leprosy: a prospective diagnostic study in 38 patients.

Histoid leprosy is a fascinating expression of multibacillary leprosy, the incidence of which was 3.6%. It was seen predominantly in males of the younger age group, who were on inadequate and irregular dosage of diaminodiphenyl sulfone. Papules, cutaneous and/or subcutaneous nodules and plaques appearing over apparently normal skin were its exquisite prospective clinical features. It was invariably supported by enormous, uniformly solid staining discrete bacilli from the lesions, in contrast to their virtual absence from the surrounding normal-appearing skin. Encapsulated tumorous mass, formed primarily by spindle-shaped histocytes, displayed either in intertwining, criss-cross or whorled fashion in haematoxylin-eosin-stained sections, were supplementary. The morphology of acid-fast bacilli was, however, similar to skin-slit smears.