Histopathology of skin lesions in leprosy.

INTRODUCTION Histopathological examination of skin or nerve biopsies or the demonstration of lepra bacilli in skin smears are the only laboratory means of confirming a diagnosis of leprosy.' The histological features are particularly useful in the early stages when there i s a sparsity of bacilli in skin smears. The histological changes in the skin in leprosy are p r ~ t e a n , ~ ~ and it is essential for a histopathologist dealing with skin biopsies from leprosy patients to be aware of these diverse manifestations. A review of 1,710 consecutive skin biopsies performed a t the University Hospital, Kuala Lumpur between January 1968, and December 1978, revealed 76 cases of leprosy. The findings are presented in this paper. MATERIALS AND METHODS The skin biopsies were fixed in 4% formaldehyde, embedded in paraffin and stained with hematoxylin and eosin. In addition, sections from the 76 cases of leprosy were stained by the Fite-Farraco method for acid fast bacilli. The lesions were classified on the basis of histopathological features into tuberculoid (TT), borderline tuberculoid (BT), borderline (BB), borderline lepromatous (BL) and lepromatous leprosy ( LL).',~