Pigmented Poroid Hidradenoma: a case reportAbstract : Poroid hidradenoma (PH) is an infrequently encountered benign adnexal neoplasm exhibiting eccrine differentiation. Histopathologically, PH displays a distinctive combination of hidradenoma-like architectural organization characterized by a purely intradermal localization with both solid and cystic components, and cytological attributes of poroid neoplasms, consisting predominantly of poroid and cuticular cells(1). In the present report, we document a case of pigmented PH arising on the thigh of a 44-year-old male patient and discuss its characteristics and clinical course.Introduction : Cutaneous adnexal tumors represent benign or malignant proliferations arising from one of the four primary skin appendages: hair follicles, sebaceous glands, apocrine glands, and eccrine glands(1) (2). Their classification is based on the morphological differentiation toward one or more of these adnexal structures. Sweat gland tumors encompassing both eccrine and apocrine lineages constitute a relatively uncommon subset of benign adnexal neoplasms, exhibiting a broad histopathological spectrum(1). Poroid hidradenoma (PH) is an uncommon benign cutaneous adnexal tumor and the most recently recognized entity within the poroma group. It originates from eccrine sweat ducts and is characterized histologically by a combination of solid and cystic components entirely confined to the dermis, without epidermal connection(1). First described in 1990, this tumor was subsequently classified among four recognized variants of poroid neoplasms based on the localization of neoplastic cells: poroid hidradenoma, eccrine poroma, dermal duct tumor, and hidroacanthoma simplex. Given their eccrine gland origin, all of these variants are localized entirely within the dermis(3). In the present report, we document a case of pigmented PH arising on the thigh of a 44-year-old male patient and discuss its characteristics and clinical course.Case Report : A 44-year-old male patient with no significant past medical, surgical, or family history presented with a painless mass on the anterior aspect of the left thigh growing for 2 years. He reported no symptoms such as itching or burning at the site of the lesion and denied any associated pain or weight loss. Examination showed a single exophytic tumor, black and pink in color, 4 × 3 cm in size, well defined, with a multilobulated granulomatous appearance. (Figure 1).Given the pigmented aspect of the lesion, a surgical excisional biopsy with a safety margin was performed to rule out the diagnosis of melanoma, followed by primary intention closure of the wound. Histopathology showed an intradermal epithelial neoplasm with focal epidermal connection, exhibiting solid and cystic components, and consisting of small, uniform basaloid cells. Within it, there were duct-like structures containing dendritic melanocytes with melanin deposits (Figure 2). The lesion appeared within 1 mm of the surgical resection margin. The diagnosis of pigmented PH was confirmed. The patient’s surgical site showed complete healing on routine follow-up examinations, without evidence of tumor recurrence.