Sinonasal Phosphaturic Mesenchymal Tumors Without Any Nasal Symptoms: A Case Report and Literature Review

Objective: We present a case of phosphaturic mesenchymal tumor (PMT) in the left ethmoid without any nasal symptoms in a 63-year-old woman. Initially diagnosed with postmenopausal osteoporosis, 2-year history of hypophosphatemia and a significantly higher uptake of Fluorine-18 ( 18 F)-AlF-NOTA-octreotide ( 18 F-OC) in the left ethmoid sinus, provided crucial information for accurate diagnosis. Methods: We presented a case with chart review and conducted review of the literature. Results: The patient endured 1-year history of weakness and bone pain but without any nasal symptoms before a tissue diagnosis was eventually reached. It is a challenging diagnosis to make-patients present with non-specific clinical symptoms and the culprit neoplasm is often tiny in size and difficult to detect. It emphasizes the importance of thorough patient history-taking and the whole-body functional imaging. Conclusions: Sinonasal PMTs are rare, and because of this most otolaryngologists are unfamiliar with its clinical presentation. This case highlights the importance of early diagnosis to enable prompt intervention and reduce the burden of associated symptoms.