Melanotic Oncocytic Metaplasia of the Nasopharynx in the Patient with Suspicious Hemoptysis: Case Report

Melanotic oncocytic metaplasia (MOM) in the nasopharyngeal space is a very rare entity. Only 35 cases have been reported in the English literature, and most patients were East Asian males between 60 and 70 years of age. MOM presents as a brown or black lesion with slight elevation of the mucosa. These lesions are benign and defined as cellular enlargement with eosinophilic granular melanin-pigmented cytoplasm caused by mitochondrial accumulation. However, such presentation can lead physicians to misjudge MOM as a malignant lesion. Recently, we experienced a case of MOM of the nasopharynx. A 58-year-old woman was admitted to the internal medicine department with small-volume hemoptysis and referred to the ENT department for evaluation. She was a regular smoker without any medical history. Sinus endoscopy showed black pigmented lesions on both the torus tubaris and left posterior tonsillar pillar, with low bleeding risk. Excisional biopsy of the lesion was performed, and oncocytic metaplasia was confirmed pathologically. Hemoptysis showed spontaneous remission and no recurrence or other symptoms over 12 months of follow up. Melanotic oncocytic metaplasia in the nasopharynx should be clinically recognized to avoid misdiagnosis as a malignancy like melanoma.