Sections reveals a highly vascular neoplasm characterized by a dense, intricate network of thin-walled, variably sized capillary channels often filled with red blood cells. Interspersed within this prominent vascular meshwork are nests and sheets of neoplastic stromal cells exhibiting abundant, clear to finely vacuolated, lipid-rich cytoplasm. The nuclei of these clear cells show mild to moderate pleomorphism, appearing round to oval and occasionally hyperchromatic. Additionally, areas of fresh hemorrhage, microcystic changes, and scattered hemosiderin-laden macrophages are present within the background stroma.
Based on the prominent clear cell morphology paired with the rich capillary network located in the posterior fossa, the primary differential diagnosis is hemangioblastoma. To confirm this possibility marker study is needed (Inhibin, D2-40, S100, GFAP, CK).
History of a posterior fossa hemangioblastoma (post-operative as of May 2025), now presenting with vertigo and choking sensations; a follow-up contrast-enhanced brain MRI reveals a cystic and solid enhancing lesion at the previous operative site (inferior posterior mid-cerebellum and cranio-cervical junction) that is compressing the right side of the medulla oblongata and touching the 4th ventricle, consistent with residual or recurrent tumor.
Soft tissue fragments collectively measured 1.5x1.2x0.8 cm, totally embedded.