The characteristic jigsaw puzzle architecture of islands composed of uniform basaloid cells can be appreciated.
The peripheral basaloid cells are darker and smaller whereas the central cells are larger and lighter.
Cylindroma is a benign skin appendange tumor. The solitary sporadic form occurs in middle-age adults and multiple lesions may arise in an autosomally-dominant fashion. The multiple cylindromas may coalesce on the scalp, forming the so-called "turban tumor", very unfortunate and disfiguring condition indeed.
If the cylindromas are associated with other skin appendage tumors such as trichoepitheliomas and spiradenomas, the patient most likely has Brooke-Spiegler syndrome (BSS). Other cutaneous lesions reported in BSS include organoid nevi (nevi sebaceus), syringomas and basal cell carcinomas. The culprit mutation is of the CYLD gene located in chromosome 16q12-q13 (Scheinfeld).
Histologically, islands of basaloid cells are arranged in a "jigsaw puzzle" pattern and surrounded by a thick hyalinzed basement membrane. The peripheral basaloid cells are small and dark and the central cells are larger and lighter (Fletcher).
Clinically, it appears as a fleshy nodule of various sizes, most common on the scalp.
→Multiple cylindromas may occur in Brooke-Spiegler Syndrome.
→When multiple cylindromas merge on the scalp, they can form the so-called "turban tumor".
Fletcher CDM, ed. Diagnostic Histopathology of Tumors. 3rd Ed. Philadelphia, PA: Elsevier; 2007: 1459.
Scheinfeld NS, Mokashi A et al. Cylindroma: eMedicine. Last updated on 7 Oct 2010. Available at: emedicine.medscape.com/article/1056630-overview