A 25-year-old woman presents with multiple firm, shiny, skin-coloured cutaneous and subcutaneous nodules distributed symmetrically on the limbs. Slit-skin smear has a bacterial index of 6+. Histopathology of a nodule shows spindle-shaped histiocytes arranged in interlacing fascia resembling dermatofibrosarcoma. What is the diagnosis?
- A Borderline tuberculoid leprosy
- B Histoid leprosy ✓
- C Erythema nodosum leprosum
- D Pure neuritic leprosy
Correct answer: B. Histoid leprosy
Explanation
Histoid leprosy is a rare, highly resistant variant of lepromatous leprosy presenting as discrete, firm, shiny nodules and plaques on an apparently normal background skin. Histology shows spindle-shaped or elongated histiocytes in whorled storiform patterns packed with AFB, mimicking a fibrohistiocytic tumour. It carries a very high bacterial index. Borderline tuberculoid disease has epithelioid granulomas with low BI, ENL shows neutrophilic inflammation superimposed on foamy macrophages, and pure neuritic leprosy involves nerves without skin lesions.
Reference: Harrison Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.