Malignant eccrine spiradenoma: a previously unreported presentation and review of the literature.

Malignant eccrine spiradenomas (MESs) are rare tumors arising from previously benign eccrine spiradenomas. A review of the literature reveals only 25 published reports of malignancy arising from eccrine spiradenoma and no prior reports of an MES of the scalp. The tumors have a metastasis rate of >50 per cent in reported cases with high resultant mortality rates. We present the first case report of a single MES of the scalp. Multiple resections were required for local control. Both magnetic resonance imaging and lymphoscintigraphy were used to assess regional spread. A review of the literature follows to include histopathology, diagnosis, and both surgical and adjuvant therapeutic options.