Myeloid sarcoma of the nasal cavity in a 15-month-old child: A case report.

INTRODUCTION Myeloid sarcoma (MS) is a rare tumor mass. It may occur at any extramedullary anatomic sites but is uncommon in the sinonasal location.MS commonly presents concurrently with acute myeloid leukemia (AML), but it may predate AML over several months or years, named isolated MS. PATIENT CONCERNS We report a case of a 15-month-old child who presented with mouth breathing, bilateral rhinorrhea, palpebral edema and proptosis. The routine blood tests were normal for the first few months. Computed tomography scan revealed neoplasm in nasal cavity. DIAGNOSIS The patient was definitely diagnosed with isolated MS in the nasal cavity through immunohistochemistry combined with clinical features and radiological investigations, and MS further progressed to AML which was confirmed by hematologist. INTERVENTIONS Endoscopic sinus surgery was performed to acquire specimens. After diagnosis, the patient was promptly treated with systemic chemotherapy. OUTCOMES All symptoms gradually subsided and the mass of nasal cavity was invisible. No relapse occurred during follow-up. CONCLUSION Sinonasal MS may be misdiagnosed and should be considered when symptoms persist and worsen. Prompt clinic examinations are essential for cases with suspected MS. Diagnosis of MS is dependent on the immunohistological investigations combined with clinical features, radiological investigations. Early diagnosis and systemic chemotherapy are vital for patients to achieve best prognosis.