Fine needle aspiration cytology, a useful tool for the diagnosis of specific leprous osteitis

Leprosy is known to affect the nerves, skin, respiratory tract and eyes commonly. Leprosy also afflicts bones, the sites of predilection for bone damage include small bones of hands and feet. Advanced bone changes are rarely encountered. We describe a case of specific leprous osteitis diagnosed by fine needle aspiration cytology (FNAC). An 18 year old male presented with multiple swellings and ulcers over the limbs since two months. A 3x2 cm hard swelling with ulceration was seen over distal left ring finger, X-ray of which showed an osteolytic lesion over the distal interphalangeal joint (DIP). FNAC from the lytic lesion showed foamy macrophages, a few lymphocytes and epithelioid cells with strongly positive staining for acid-fast bacilli (AFB). A diagnosis of specific leprous osteitis was made. FNAC is a simple, cost effective and minimally traumatic procedure and may be used as a mode of investigation for the diagnosis of specific leprous osteitis.