Cytological Diagnosis of Erythema Nodosum Leprosum in Clinically Unsuspected Cases: A Report of Two Cases.

Leprosy is a chronic infectious disease caused by Mycobacterium leprae. The manifestations of this disease varies across the spectrum of tuberculoid (TT) to lepromatous (LL) leprosy. The course of this indolent disease is interrupted by acute exacerbations in the form of leprare actions. Erythema nodosum leprosum (ENL), a type 2 lepra reaction, occurs in lepromatous or borderline lepromatous cases, usually in response to multidrug therapy. Early detection and timely management of these patients is important to reduce the associated morbidity. We report two clinically unusual cases of ENL on fine-needle aspiration cytology. In one case, antileprosy treatment was completed 10 years back, whereas in the other case, ENL was the presenting feature of the disease. Cytological examination of swelling in both the cases showed neutrophils, lymphoid cells, clusters of foamy macrophages, histiocytes, and giant cells. Fite stain was positive, which confirmed the cytological diagnosis of ENL.