The smear of the lesion reveals a bacterial Index (BI) of 4+. Smears from the ear lobes, thigh and arm are negative.
The skin biopsy reveals epidermal atrophy and mild orthokeratosis.
Small aggregates of histiocytes and lymphocytes are seen around the vessels, skin adnexa, and in and around the nerves.
The granuloma fraction is 5%; solid acid fast bacilli are seen in some, both singly and in small clusters of 3 to 5 bacilli; the BI of the granuloma is 2+.