Seromucinous Hamartoma of the Sinonasal Cavity.

Benign tumors or malignant neoplasms must be evaluated in patients with unilateral nasal cavity mass lesions. The 3 most prevalent unilateral benign mass lesions in such individuals are nasal polyps (NPs) and inverted papillomas (IPs). Although rare, it should be kept in mind that sinonasal hamartomas can be occasionally diagnosed as well. Among sinonasal hamartomas, respiratory epithelial adenomatoid hamartoma is more prevalent, with seromucinous hamartoma (SMH) being the second most common. Unlike NPs, sinonasal hamartomas are benign tumors with growth potential, which means it should not be undertreated and warrants surgical removal for treatment. However, sinonasal hamartomas do not have local invasion or malignant transformation potential like IPs; hence, it is vital not to overtreat them. Therefore, understanding the histopathology of SMH and thereby establishing proper surgical planning prior to the surgery remains crucial in such cases. Here, we present a successfully treated case of SMH with a distinctive radiographic, gross, and pathological clinical image of SMH.