Nasal chondromesenchymal hamartoma (NCMH): a rare DICER1-associated tumour in an adult male.

An adult male presented to the ENT clinic with a 1-year history of unilateral nasal blockage. He had presented to another institution 5 years previously with the same issue, undergoing resection of what was reported to be a benign inflammatory polyp with osseous metaplasia. Detailed examination revealed a large mass filling the left nasal cavity. Excisional biopsy and secondary specialist review of pathology revealed nasal chondromesenchymal hamartoma (NCMH) with associated DICER1 mutations. NCMH is a rare, benign tumour of the sinonasal tract, presenting more often in the early childhood, with symptoms related to the site and extent of the tumour. As highlighted in this case, complete excision is mandatory for definitive diagnosis and treatment of NCMH, and an awareness of the association with DICER1 mutation, which can predispose individuals to a range of neoplasia, is key to providing appropriate genetic counselling.