A Confounding Case of a Skin Biopsy

An 88-year-old gentleman with no significant past and family history, presented with an erythematous indurated plaque-like lesion on the right leg since 3 to 4 months along with few lesions on the abdomen and chest. He had no itching sensation in the region. On examination, indurated erythematous plaques were noted. There was no ulceration of the skin. All laboratory investigations done were within normal limits. He was treated with topical steroids but it yielded no response. Subsequently, he underwent a skin biopsy from the lesional area. Grossly, skin biopsy measured 0.5 x 0.5 x 0.2 cm. On microscopic examination, skin biopsy showed thinned out atrophic epidermis with a well-defined Grenz zone in the papillary dermis (Figure 1A). There was pandermal infiltrate of diffuse sheets of neoplastic round cells intermediate in size (Figure 1B) along with dense dermal sclerosis (Figure 1D). The cells had pleomorphic convoluted nuclei with coarse chromatin and inconspicuous nucleoli (Figure 1C). Mitosis was brisk (inset). The follicular units are also surrounded and focally infiltrated by the neoplastic cells. Epidermotropism was absent.