Syringocystadenocarcinoma papilliferum with locoregional metastases.

Syringocystadenocarcinoma papilliferum (SCACP) is a rare malignant counterpart of syringocystadenoma papilliferum (SCAP). To date, less than 30 cases have been reported, and of those, only three had locoregional metastases [1,2]. Herein, we report a case of a 42-year-old man with a rapidly growing nodule on his right parietal scalp ultimately diagnosed as SCACP arising in association with a preexisting SCAP and nevus sebaceus. This case differs from prior reports in the tumor's rapid growth and aggressive course with the development of locoregional metastases within 5-weeks from initial presentation.