Unilateral Nasal Obstruction: a Rare Presentation of Acute Myeloid Leukaemia.

Myeloid sarcoma, and, with it, Acute Myeloid Leukaemia (AML), is a rare but important differential diagnosis in the consideration of unilateral nasal blockage. These lesions are often misdiagnosed as lymphoma or poorly differentiated carcinoma. We report the case of a patient with unilateral nasal blockage who underwent Endoscopic Sinus Surgery and biopsy. Histology revealed myeloid sarcoma and she was diagnosed with AML. Genetic testing could not be fully undertaken as the biopsy samples were preserved in formalin, which can degrade the quality of the DNA required for the more sensitive fms-like tyrosine kinase 3-internal tandem duplication (FLT3 ITD) test. Given that these levels have a significant impact on treatment decisions, a further biopsy, preserved in saline, was required. This case exemplifies the need for Ear, Nose and Throat clinicians to have a high index of suspicion for this lesion, and a working knowledge of the testing requirements for samples taken.