33044 Desmoplastic melanoma vs dermatofibroma: A challenging histopathologic case

Abstract

A 67-year-old male presented with a 3-year history of a pigmented lesion on his posterior right shoulder which had recently become darker and bigger. On examination he had a 15- × 18-mm firm brown/pink nodule with central white-scar, dimpling sign positive and peripheral pigmentation (Figure 1). An excision biopsy was performed in view of the findings. Initial histology reported a lentiginous proliferation of atypical melanocytes with junction nests in varying sizes and pagetoid spread (Figure 2).