Cylindroma, also known as a dermal eccrine cylindroma, is a benign tumor that occurs most frequently on the face and scalp, but any part of the body may be affected. It is most often a solitary lesion that is not considered heritable. The tumor ranges in size from just a few millimeters to several centimeters in diameter. Cylindromas characteristically occur in individuals between 30 and 50 years, and women are affected twice as often as men. The tumors are commonly slow growing and may be painful or asymptomatic. They are typically firm and rubbery; however, ossification has been reported to occur, in which case they may feel hard. Lesions range in color from pinkish-red to blue.

Multiple cylindromas may occur in the dominantly inherited Brooke-Spiegler syndrome, where they are seen in association with trichoepitheliomas and spiradenomas, as well as basal cell carcinomas (BCCs) in some kindreds. In this context, the cylindromas are so numerous that they may cover the scalp like a turban. In familial cylindromatosis, multiple cylindromas only are seen. This condition is allelic to Brooke-Spiegler syndrome and is thought to be a phenotypic variant.

Cylindromas are benign; however, there have been rare reports of individual cylindromas undergoing malignant transformation, particularly in tumors of the scalp that have been present for long duration.