A case of eccrine spiradenoma presenting as a painless, reddish nodule on the forearm

Abstract

Sir, Eccrine spiradenoma (ES) is a rare and benign adnexal tumor originating from the eccrine glands. It is usually located in the truncal region and is most common in young adults twenty to forty years old. Herein, we report a clinical, dermoscopic, and histological description of the case of an elderly male with an atypical tumor localization. A 74-year-old male presented with a painless, nodular mass on the anterior aspect of the left forearm, growing progressively over the previous year. He had no medical history. A dermatological examination revealed a solid, skin-colored nodule with a central ulceration and a peripheral collar, measuring approx. 1 to 1.5 cm in diameter, not bleeding on contact (Fig. 1a). There were no similar nodules or palpable lymph nodes. Dermoscopy was performed with DermLite 4. It demonstrated a vascular pattern of branched vessels and a central ulceration with a reddish background and scattered blue clods. It also showed a yellowish-brown, serohematic crust surrounding the ulceration and the reddish background (Figs. 1b and 1c). Upon histopathologic examination, the excised nodule revealed a tumoral proliferation, which was well demarcated from the surrounding tissue. It consisted of sharply defined lobules and cords intertwined into a puzzle-like structure (Fig. 2a). Two cell populations were identified: small basaloid cells and larger cuboidal ones. The cells displayed high mitotic activity yet no abnormal mitotic figures and no necrotic background. The section also showed numerous amorphous eosinophilic deposits within the cell cords and a richly vascularized stroma (Fig. 2b). The excision was complete and there were no recurrences on subsequent checks.