Clinico-histopathological concordance in leprosy

Histopathological examination of biopsies from 111 patients with clinically diagnosed leprosy was carried out in order to observe the clinico-histopathological correlation. Clinical diagnosis was based on Ridley and Jopling (R-J) classification and World Health Organization (WHO) classification. The concordance rate between the two clinical classifications was 73.8%. Sections were stained with haematoxylin and eosin (H&E) and Ziehl-Neelsen's (Z-N) stains. The histological classification was as per the R-J criteria. Skin biopsy showed evidence of leprosy in 104 cases (93.69%). Overall concordance was observed in 58.6% (R-J) and 85.6% (WHO classification). The kappa test, when applied, showed significant agreement between clinical and histopathological diagnosis (z=11.775; P<0.001). Individual subtypes showed variable concordance rates which were again higher using WHO classification. When some of the subtypes were combined, the concordance rate was 83.02% for TT+BT; 72.58% for BT+BB+BL; 73.91% for BL+LL; 80.77% for BL+HL and 100% for LL+HL. (See Introduction for definitions of abbreviations.) The present study highlights the importance of histopathological examination for exact subtyping of leprosy, so as to facilitate the institution of accurate mode of therapy and regular follow-up of patients to prevent undesirable complications.