Clinicopathological Discordance Revealing a Nasal Arteriovenous Malformation Mimicking Sebaceous Gland Hyperplasia

INTRODUCTIONArteriovenous malformations (AVMs) are rare congenital vascular anomalies that arise from abnormal embryologic development of the vascular system and are characterized by direct connections between arteries and veins without an intervening capillary bed [1]. These lesions are typically high-flow in nature and may progressively enlarge over time, leading to functional impairment, cosmetic deformity, or bleeding complications [1,2].Although AVMs can involve various organs, lesions affecting the head and neck region are relatively uncommon, with nasal arteriovenous malformations representing a particularly rare subset [2,3]. The clinical presentation of nasal AVMs is highly variable and may include epistaxis, nasal obstruction, facial swelling, or cutaneous erythema [4]. However, atypical presentations without classical vascular signs have been reported and may closely mimic benign dermatological or inflammatory conditions, resulting in delayed or incorrect diagnosis [3,5].Sebaceous gland hyperplasia is a common benign adnexal condition of the face and is rarely associated with underlying vascular anomalies [8]. When nasal AVMs present with predominant cutaneous or adnexal features, clinical suspicion for a vascular lesion may be low, particularly in the absence of pulsation or bleeding [3,5]. Such atypical presentations pose a diagnostic challenge and highlight the limitations of relying solely on clinical examination or superficial histopathology.We report a rare case of nasal arteriovenous malformation presenting primarily as sebaceous gland hyperplasia, emphasizing the importance of clinic radiological correlation and awareness of unusual dermatological manifestations of vascular anomalies.