Study of Histopathological Spectrum of Leprosy with Special Reference to Bacteriological Index in a Tertiary Care Centre

Abstract

Leprosy, caused by Mycobacterium leprae, remains a challenge in endemic regions despite declining global incidence. Its clinical and histopathological spectrum reflects the host’s immune status, ranging from the paucibacillary tuberculoid form to multibacillary lepromatous leprosy. This study retrospectively analyzed 75 skin biopsy specimens from clinically suspected leprosy cases at a tertiary care centre. Using routine hematoxylin and eosin (H&E) and modified Fite–Faraco staining, the lesions were classified according to the Ridley–Jopling spectrum. The results revealed that lepromatous leprosy (LL) was the most common subtype (32%), followed by borderline tuberculoid (BT; 28%), borderline lepromatous (BL; 13.33%), mid-borderline (BB; 9.33%), tuberculoid (TT; 9.33%), and indeterminate leprosy (IL; 8%). The mean patient age was 36.52 years with a slight male predominance (61.33% male). Overall clinico-histopathological correlation was 72%, with 100% agreement in TT cases and only 42.86% in BB. Fite–Faraco staining was positive in 62.66% of cases, with strong acid-fast bacilli detection in LL and BL lesions (BI scores up to grade 6) and negativity in TT. These findings support the integration of clinical evaluation, histopathology, and bacteriological index determination for accurate diagnosis and effective treatment planning in leprosy.