Painful spitz naevus sole of foot

Abstract

A 21-year-old student of sports science presented with a 12-month history of a painful nodule on the sole of her left foot, which severely constrained her sporting activities. She was otherwise well. On examination there was a bluish pink 7-mm nodule on the arch of her left foot (Fig. 1). It was firm, exquisitely tender and she walked with a slight limp. The lesion was curetted and sent for histological diagnosis. The specimen showed a symmetrical wedge-shaped compound melanocytic lesion reaching the margins of the biopsy. The overlying epidermis was acanthotic and hyperkeratotic. Junctional nests were present and there was clefting between them and the epidermis (Fig. 2). Near the nests were eosinophilic globules (Kamino bodies) and pigment-laden macrophages. The lesion consisted of a mixture of large spindle and epithelioid cells with abundant eosinophilic cytoplasm and plump nuclei with prominent nucleoli. There were a few mitoses but none was atypical. Single epithelioid melanocytes were present deep within the lesion (outlier cells) and there was maturation with depth in the dermis. The histological features were those of Spitz naevus. There was significant reduction in the severity of her pain after curettage but the pain subsequently recurred. In view of this and possible incomplete excision, the scar was re-excised with a narrow margin. Histology confirmed complete excision of the residual naevus. Her symptoms have since subsided.