Poroid hidradenoma. A case presentation.

Poroid hidradenoma is a benign soft-tissue neoplasm with eccrine differentiation. It is the newest addition to a group of neoplasms known as poromas. Although it becomes malignant in less than 1% of cases, its histologic characteristics may resemble those of malignant neoplasms; thus it is easily misdiagnosed. Twenty-one percent of poroid hidradenomas occur in the extremities. The histologic and clinical features of this tumor are presented here, along with a case report.