title: Histopathological examination of skin biopsies from an epidemiological study of leprosy in northern Malawi.
abstract: This report describes the histopathological findings in 686 biopsies obtained from 664 individuals during the course of a total population survey for leprosy in Northern Malawi. The criteria for the selection of cases for biopsy, the biopsy technique using a 4-mm punch, fixation method, transport of biopsies from Africa to the United Kingdom, and the method of coding histopathological results are described. Fifty-two percent (354) of the biopsies showed definite evidence of leprosy on histopathological examination. Using the Ridley-Jopling system, these biopsies were classified as follows: TT = 60 (17%); TT/BT = 68 (19%); BT = 194 (55%); BT/BB = 4 (1%); BB = 4 (1%); BB/BL = 4 (1%); BL = 7 (2%); BL/LL = 3 (1%); LL = 6 (2%). In addition, four (1%) biopsies were classified as "indeterminate" on histology, meaning that although there was evidence of leprosy it was not possible to provide a precise classification. A further 117 biopsies (17% of the total) had abnormal changes, often including epithelioid cell granulomas, possibly caused by leprosy but lacking specific criteria for that diagnosis. Finally, 203 (30%) of the biopsies had nonspecific (often minimal) changes, and 11 (2%) of the total showed evidence of some dermatological condition other than leprosy. Histopathological examination of biopsies in this study confirmed the clinical classification in 98% of the cases in which the histopathologist found evidence of leprosy, and supplied further evidence for the very high proportion of paucibacillary cases in this part of the world.
mesh_terms: D001706:Biopsy / Q000379:methods; D005260:Female; D006801:Humans; D007918:Leprosy / Q000453:epidemiology / Q000473:pathology*; D008295:Malawi; D008297:Male; D008403:Mass Screening / Q000379:methods; D012867:Skin / Q000473:pathology*