Clinical presentation
A 72-year-old man with a history of numerous basal cell carcinomas (BCCs) on the head and neck presented to dermatology for evaluation of a new lesion. The scalp had a 7 mm firm, tender papule that had reportedly grown within 1-2 months (Fig 1, A).
Fig 1.
Pink papule on the scalp with prominent vasculature visible without further magnification (A). Dermatoscopy of spiradenocylindroma demonstrating a homogeneous salmon or pink background with superficial angulated and tortuous vessels (B).
Dermatoscopic appearance
Dermatoscopy revealed numerous angulated and tortuous vessels on a homogeneous pink background with rare shiny white lines but an absence of prominent pigment and leaf-like structures (Fig 1, B).
Histologic diagnosis
Histopathologic examination demonstrated a well-circumscribed, dermal, multinodular basophilic tumor comprised of larger pale cells centrally with smaller basaloid peripheral cells (Fig 2), with intratumoral lymphocytes and ductal structures with focal areas of basaloid tumor lobules demonstrating a “jigsaw pattern” arrangement (Fig 3), consistent with a hybrid spiradenocylindroma.
Key message.
Spiradenomas and cylindromas are related benign adnexal tumors with eccrine differentiation, commonly arising on the head. Rarely, a hybrid of both tumors presents, referred to as a spiradenocylindroma. Adnexal tumors commonly mimic BCC on dermatoscopy,1 presumably due to the frequency of arborizing vessels, which is a characteristic feature of BCC2; however, dermatoscopy of a hybrid spiradenocylindroma has rarely been reported. The lesion presented demonstrated arborizing and tortuous vessels, leading to the inclusion of BCC in the differential diagnosis, although it was unusually tender. This case further expands on the dermatoscopic findings of a rare adnexal tumor.
Fig 2.
On histopathology, there is a circumscribed, dermal, multinodular basophilic tumor at different levels (A and B, hematoxylin and eosin, 15×). Tumor nodules are comprised of larger pale cells centrally with smaller basaloid peripheral cells with globules of eosinophilic hyaline material.
Fig 3.
Focally, some tumor islands are arranged in a “jigsaw pattern,” surrounded by eosinophilic basement membrane (hematoxylin and eosin, 50×).
Conflicts of interest
None disclosed.
Footnotes
Funding sources: None.
Patient consent: The authors obtained written consent from patients for their photographs and medical information to be published in print and online and with the understanding that this information may be publicly available. Patient consent forms were not provided to the journal but are retained by the authors.
IRB approval status: Not applicable.
References
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