Metastatic malignant clear cell hidradenoma associated with bullous pemphigoid.

The clinicopathological features of a case of metastatic malignant clear cell hidradenoma (MCCH) occurring in a 72-year-old black male are reported. Unusual features of the case included the location of the tumour on the posterior trunk, the probable origination of the tumour from a benign appendageal tumour, and the occurrence of a bullous eruption immediately after surgical removal of the tumour. Clinicopathological aspects of MCCH are reviewed and treatment modalities, including chemotherapy, are discussed.