A study of mast cells in granulomatous lesions of skin, with special emphasis on leprosy.

76 skin biopsies that included material from 7 controls, 65 granulomatous skin lesions and 2 each of granulation tissue and chronic non-specific inflammation, were subjected to histopathological evaluation on haematoxylin and eosin and pertinent special stains. Mast cell study was done on slides stained by toluidine blue method, with special reference to their location, and morphology and cell count were done with the help of occculomicrometre. In normal skin, mast cell density was 11.43/mm2 with a range of 6-22/mm2 and an S.D. of 5.94. Highest value in the whole series was seen in TVC (66/mm2), followed by lupus vulgaris (50/mm2). Mast cell counts were normal in indeterminate and TT leprosy and showed a rise over the immunological spectrum BT to LL, with values in LL being 32.86/mm2 (28-40/mm2).