Abstract

Introduction:Cylindromas may develop as sporadic solitary tumors or as multiple tumors due to Brooke-Spiegler syndrome (BSS) or familial cylindromatosis (FC). Cylindrocarcinoma is a rare neoplasm that arises from a preexisting cylindroma and has the potential for metastasis. Less than 50 cases of cylindrocarcinoma have been described with less than half associated with metastases. Cylindrocarcinoma may show varying morphologies, including squamous differentiation. Case history:A 56-year-old male had an infraclavicular soft tissue mass (circumscribed,4.9 cm), two scalp nodules (circumscribed,~1 cm each), and a left posterior neck mass (irregular,7.1 cm). Multiple smaller lesions (back, cheek, etc.) were also seen on imaging. Excision of the infraclavicular mass was diagnosed as cylindroma, but biopsy of the neck mass showed nodules with nuclear atypia, increased mitoses, and infiltration. Squamous morulas and keratinization were also seen. Staging scans further identified a cervical lymph node suspicious for metastasis. Despite the intention to biopsy this node, the patient was resistant to further workup. Discussion:Cylindrocarcinomas show infiltration, loss of jigsaw pattern, nuclear atypia, prominent nucleoli, and increased mitoses. Histologic patterns of cylindrocarcinoma, in addition to the rarely reported squamous differentiation pattern, include salivary gland type basal cell adenocarcinoma-like (low-and high-grade), sarcomatoid, adenomatous, and clear-cell, among others. Of the less than 25 reported cases, suggested metastatic risk factors include high-grade features, primary scalp tumors, and being female. Treatment for metastatic cylindrocarcinoma isn’t well established but may include excision with or without chemo-/radiotherapy. Prognosis varies, but those with known CYLD mutations or BSS/FC should be followed. Conclusion:This case is meant to increase awareness of cylindrocarcinoma, including its histologic variations and risk of metastatic progression.

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