Solitary lesions are firm, rubbery nodules with pink, red, or sometimes blue coloring ranging in size from a few mm to several cm. The solitary form is nearly always found on the scalp, head, and neck. The multiple form most frequently occurs on the scalp, head, and neck and can develop on the trunk and extremities. The multiple form is autosomal dominantly inherited and is implicated on the cyld 1 gene on chromosome 16. Cylindroma is a dermal tumor without attachment to the epidermis.
Lesion is composed of numerous oval and polygonal nests molded into a jigsawlike pattern.
Masses of epithelial cells are surrounded and penetrated by a hyaline sheath. Tumor islands are composed of 2 cell types. Larger, more pale-staining cells are seen centrally. Small tubal lumina are sometimes found with careful observation. Hyaline bands, which surround tumor islands, are mostly composed of Type IV collagen.