Diagnosis: Cylindroma
Definitive diagnosis was made by shave biopsy of the left hip lesion. Histopathology demonstrated various-sized discrete aggregates of basaloid cell nests in a jigsaw puzzle–like configuration (FIGURE 2), surrounded by rims of homogenous eosinophilic material. Histologic findings were consistent with cylindroma.1
Rare with a female predominance. Solitary cylindromas occur sporadically and usually affect middle-aged and elderly patients. Incidence is rare, but there is a female predominance of 6 to 9:1.2 Clinical appearance shows a slow-growing, firm mass that can range from a few millimeters to a few centimeters in diameter. The masses can have a pink or blue hue and usually are nontender unless there is nerve impingement.2
If multiple tumors are present or the patient has a family history of similar lesions, the disorder is likely inherited in an autosomal dominant pattern (with variable expression), which can be associated with Brooke-Spiegler syndrome. This syndrome is related to a mutation of the cylindromatosis gene on chromosome 16. This is a tumor suppressor gene, inactivation of which can lead to uninhibited action of NF-kB which increases resistance to apoptosis and carcinogenesis.3 This results in production of cylindromas, trichoepitheliomas, and spiradenomas.3
Rarely, cylindromas can undergo malignant transformation; signs include ulceration, bleeding, rapid growth, or color change.2 In these cases, appropriate imaging such as computed tomography, magnetic resonance imaging, or positron emission tomography should be sought as there have been case reports of cylindroma extension to bone, as well as metastases to sites including the lymph nodes, thyroid, liver, lungs, bones, and meninges.4
Lipomas and pilar cysts comprise the differential
Lipomas are soft, painless, flesh-colored masses that typically appear on the trunk and arms but are uncommon on the face. Telangiectasias are not seen.
Continue to: Pilar cysts