Poroid Neoplasms: A Clinicopathological Study of 13 Cases

Background: Poroid neoplasms (PN) are a heterogeneous group of tumors deriving from sweat glands and folliculo-sebaceous units. Their histological classification and clinical features are challenging. Our aim was to report clinicopathological features of poroid neoplasms. Methods: it is a retrospective study including all cases of poroid neoplasms registered at our Pathology laboratory of Niamey National Hospital (from February 2020 to February 2024). Results: We registered 13 cases of benign poroid neoplasms: 10 classic poromas (CP) (76.9%), 2 poroid hidradenomas (PH) (15.4%) and 1 dermal duct tumor (DDT) (7.7%). Nine cases (69.2%) had preoperative clinical diagnosis of malignancy. The mean age was 41.1 years (range of 12 – 70 years) with a slight female predominance (sex ratio = 1.16). Only 4/13 cases (30.8%) had classical palmoplantar locations. The tumors mean size was 3.7 cm (range of 0.4 – 8 cm). All cases were well-circumscribed solid (7/13 cases, 53.8%) or solido-cystic whitish nodules (6/13 cases, 46.2%). Clear cells were present in 7 cases (53.8%), apocrine ductal differentiation (mixed or pure) in 6 cases (46.2%), keratin horns in 2 cases (15.4%), squamous eddies in 6 cases (46.2%), melanin pigments in 1 case (7.7%) and sebaceous differentiation in 2 cases (15.4%). Conclusions: Unlike what is classically reported, our study shows that apocrine ductal differentiation, younger age and non-palmoplantar locations are common in poroid neoplasms. Also, PN are often diagnosed as malignant tumors by clinicians before histopathological analysis.