Poroid Hidradenoma: A Rare Eccrine Tumor in an Unusual Location

Poroid hidradenoma (PH) is a rare benign neoplasm of eccrine origin, typically located within the dermis. It most commonly affects individuals in the sixth and seventh decades of life, though it can present at any age. The head, neck, and trunk are typical locations. This case report details a 26-year-old male with a large PH on the right hip, an atypical location. The lesion began as a small, painful nodule and progressively grew over 18 months. Initial treatment, suspected to be for an abscess, was unsuccessful. A dermatological evaluation revealed a 7 x 8 cm exophytic, ulcerated mass, and biopsy confirmed the diagnosis of PH. Histopathological analysis showed solid and cystic components, with poroid cells identified. Immunohistochemistry was positive for markers such as CEA, CK-7, and p63, which are consistent with this tumor type. Following the confirmed diagnosis, complete surgical excision was performed, and the patient remains asymptomatic with no signs of recurrence. Poroid hidradenoma is characterized by both poroid and cuticular cells, and although it is generally benign, malignant transformation has been reported in less than 1% of cases. Therefore, complete excision is recommended to reduce the risk of recurrence and malignancy. This case highlights the importance of early diagnosis and appropriate management of PH, including long-term follow-up to ensure the absence of recurrence.