#00066124

Bone marrow aspirate smear (May-Grünwald-Giemsa stain, ×100 oil immersion) demonstrating metastatic neuroblastoma. A prominent cluster of small round blue tumor cells is seen arranged in a cohesive syncytial group with central fibrillary neuropil, forming a classic Homer-Wright rosette. The neuroblasts exhibit high nuclear-cytoplasmic ratio, hyperchromatic nuclei with irregular contours, prominent nucleoli, nuclear molding, and scant cytoplasm. This pattern of infiltration is characteristic of bone marrow involvement by neuroblastoma, a common site of metastasis in advanced disease. Rosette formation aids in distinguishing neuroblastoma from other small round blue cell tumors.