Myeloid sarcoma presenting initially in the oral cavity under non-leukemic conditions: A case report

Myeloid sarcoma (MS) commonly occurs in various body parts and most frequently develops in patients with acute myeloid leukemia (AML). MS in the oral cavity under non-leukemic conditions is rare and may be challenging to diagnose. Herein, we report a case of MS that presented with initial symptoms in the oral cavity under non-leukemic conditions. A 41-year-old woman presented to our hospital with swelling of the right upper gingiva, buccal region, and neck. Although several biopsies of the oral cavity were performed, none confirmed MS. Since positron emission tomography-computed tomography showed abnormal fluorodeoxyglucose uptake in the breast, a breast biopsy was performed; MS diagnosis was accordingly made. Subsequently, the patient received chemotherapy but died 11 months after initiating primary treatment. This report shows that the initial symptoms of MS may appear in the oral cavity under non-leukemic conditions and confirming MS requires histopathological examination. However, many cases are misdiagnosed and their diagnoses delayed. Diagnostic and treatment delays can impact prognosis. Clinicians should consider biopsies of suspicious oral lesions to ensure early diagnosis.