An Uncommon Case of Non-leukemic Myeloid Sarcoma of the Face in a 71-year-old Filipino Female: A Case Report.

Myeloid sarcoma is a tumor that demonstrates extramedullary proliferation of myeloid blasts with or without maturation. It may present as an isolated tumor or may have peripheral or marrow involvement. The diagnosis of myeloid sarcoma is highly challenging as it may mimic other tumors. A 71-year-old woman with an Eastern Cooperative Oncology Group (ECOG) performance score of 2 presented with a progressively enlarging right facial mass that had been growing for 18 months. Initially, it appeared as a 1x1 cm erythematous pustular lesion. A core biopsy suggested carcinoma, but COVID-19 delayed immunohistochemical (IHC) testing. As the mass grew, eventually covering more than half of her face, a CT scan revealed a large, multilobulated mass involving the periorbital areas, nose, and upper lip. A repeat biopsy showed atypical round cell proliferation, and immunohistochemical staining confirmed myeloid sarcoma with CD34 and CD117 positivity. Bone marrow aspiration and biopsy ruled out leukemia. The diagnosis of non-leukemic myeloid sarcoma was established. The patient was referred to plastic surgery, ophthalmology, and otorhinolaryngology for co-management of the mass. Initial treatment began with azacitidine, a hypomethylating agent. However, after completing only one cycle of chemotherapy, she declined further treatment for personal reasons, choosing not to continue with the planned therapeutic regimen. Non-leukemic myeloid sarcoma of the face in an elderly patient is rare. Diagnosis was confirmed via biopsy and immunohistochemical studies. Treatment with azacitidine was chosen based on the patient's ECOG score of 2. However, there is no consensus on its management, and the role of systemic chemotherapy remains debated. Continuous monitoring for progression to acute myeloid leukemia (AML) is crucial, as early detection significantly impacts prognosis and informs treatment decisions.