A malignant eccrine spiradenoma of the scalp

Abstract

Malignant eccrine spiradenoma (MES) is an extremely rare but aggressive tumour, resulting in high mortality. We report the first case in the UK of metastatic MES on the scalp of a 37-year-old man who initially presented with a raised nodular mass which had grown rapidly over a few months. Excision biopsy of the lesion was performed and histology confirmed MES with evidence of cytological atypia and necrosis. A further wide local excision of the lesion with a 1 cm surgical margin was performed and full clearance was achieved. At 10-month follow-up another similar lesion had developed close to the previously excised area. A CT scan demonstrated metastatic lesions in the lungs, liver and pelvis, and subsequently chemotherapy was initiated. Although MES is uncommon, it has a high propensity to metastasise, therefore prompt identification, treatment and close follow-up of these tumours is essential.

Figure 1

A large non-ulcerated well-defined purplish nodule on the right side of the parietal scalp.

Figure 2

High-power (×40 magnification) histological view showing spiradenoma cells with glandular differentiation and high-mitotic count suggesting malignant behaviour.