Lateral pharyngeal wall myeloid sarcoma as a relapse of acute biphenotypic leukemia: a case report and review of the literature

INTRODUCTION Myeloid sarcoma is a rare extramedullary malignant tumor composed of immature myeloid cells. The tumor can affect any part of the body. Involvement of the oral cavity and nasopharynx has been reported in 50 cases. We report a case describing myeloid sarcoma affecting the lateral pharyngeal wall. CASE PRESENTATION A 31-year-old Arabian man who had acute biphenotypic leukemia treated with chemoradiation and allogeneic stem cell transplant was referred to our department with sore throat and a mass lesion in his lateral pharyngeal wall after failed antibiotic therapy. Biopsy of his lesion revealed myeloid sarcoma. He was referred to the Department of Hematology-Oncology for further evaluation that showed no other lesions.The patient was diagnosed with isolated extramedullary myeloid sarcoma of his lateral pharyngeal wall as a relapse of acute biphenotypic leukemia and managed with chemoradiation. CONCLUSIONS Myeloid sarcoma of the pharynx is a rarely encountered malignancy in the practice of otolaryngology-head and neck surgery. It can develop de novo, but may also represent relapse of leukemia. Thus, it should be considered in the differential diagnosis of any pharyngeal lesions in patients with leukemia.