A 15-year-old female presented to our Dermatology outpatient department with multiple nodules over bilateral arms, face, left thigh, and bilateral soles for 1 year [Figure 1A-F] with no family history or contact history. Her viral marker for HIV, HBsAg, and HCV was negative. On examination, the lesions were multiple, well-defined, erythematous, nontender, firm-to-hard nodules with the presence of yellowish black crust over few of the chin nodules. There were few flat-topped ill-defined grouped papules coalescing to form small plaques over bilateral soles. Her viral markers were negative. Clinical differentials were given as juvenile xanthogranuloma, rhinosporidiosis, and deep fungal infection.
Since the differential of leprosy was not considered in this case, the clinician had sent the patient for FNAC of the nodules. Cytosmears showed many scattered foamy macrophages, lymphocytes, and neutrophils [Figure 2A-C]. Negative images were seen within the macrophages and in the extracellular background. ZN stain was positive for the negative images that were seen on the Giemsa stain [Figure 2D]. A diagnosis of atypical mycobacterial infection was suggested. We were able to exclude the differential diagnosis of xanthogranuloma which shows foamy macrophages, Touton giant cells but AFB stain negative. From the nodular lesions, the patient was then advised for skin punch biopsy and GeneXpert testing for tuberculosis. Histopathology revealed epidermis with orthokeratosis, hypergranulosis, flattened rete ridges, and spongiosis. The underlying dermis showed dense perivascular, perifollicular, and perineural lymphomononuclear cell infiltrate along with foamy histiocytes and necrosis [Figure 3A-C]. Fite-Faraco staining for lepra bacilli showed a bacillary index of 6+ [Figure 3D]. Histopathological features were consistent with the Histoid variant of Hansen's disease. GeneXpert testing for Mycobacterium tuberculosis was negative.
The patient had come with her father on a second visit along with FNAC and biopsy reports. On re-evaluation, she had thick bilateral ulnar and common peroneal nerves. Positive family history in the father was noted. The patient was then started on multibacillary (MB) multidrug therapy (MDT) (rifampicin, clofazimine, and dapsone) for a duration of 12 months. She was on follow-up after 1 month with subsidence of lesions.