Fine needle aspiration cytology of myeloid sarcoma in 6-month-old infant: A case report

초록

Myeloid sarcoma, also termed extramedullary myeloid tumor, granulocytic sarcoma or chloroma, is a tumor mass consisting of myeloblasts, monoblasts, or hematopoietic precursors occurring at an anatomic site other than the bone marrow. The median age of myeloid sarcoma is 56 years. Recently, we experienced a 6-month-old female infant with myeloid sarcoma. The patient presented with multiple slightly dusky blue firm nodules on the trunk at birth. Acute myeloid leukemia was diagnosed by punch biopsy of skin and bone marrow biopsy at that time. Five months later, she presented with a 5cm-sized soft mass in left scapular area. On magnetic resonance image, the mass involved supraspinatus, infraspinatus, teres minor, and subscapularis muscle with scapular bone infiltration. Ultrasound-guided fine needle aspiration cytology was performed. The cytologic finding showed relatively high cellularity with isolated intermediate sized atypical cells showing round to oval nuclear contour, thin nuclear membrane, fine chromatin, and promient nucleoli with scant to moderate amount of pale blue cytoplasm, suggesting the feature of myeoloblasts. Eosinophilic or azurophilic cytoplasmic granules were not identified. The needle biopsy was also performed. The tumor infiltrated the skeletal muscle and composed of monotonous immature myeloid cells showing round to oval nuclei and prominent nucleoli with expressing myeloperoxidase and CD68 on immunohistochemistry.