Clinical history: 45 year old female with nodule on back. Excisional biopsy performed.
What is your diagnosis?
Discussion and answer
Microscopic Description: The sections show a portion of skin with a poorly circumscribed dermal tumor composed of irregularly-shaped islands and cords of basaloid cells surrounded by thickened eosinophilic hyaline bands. The nests fit together like a "jig-saw puzzle". There is no involvement of the epidermis. The tumor islands are composed of 2 cell types: A peripheral cell with a dark staining nucleus and a palisading arrangement, and a larger cell with a vesicular nucleus, which is more centrally located.
Cylindromas are benign skin adnexal tumors with a strong female predominance. The majority are found on the head and neck.