For many years the only mechanism for observing gross pathologic features of CNS neoplasms was to examine brains extracted after death. However, advancements in imaging technology now allow providers to observe typical gross neuropathological findings in the brains of living patients. Some brain tumors have characteristic MRI findings, an example of which is a cyst... Continue Reading →
Astrocytomas (i.e. glial tumors that diffusely infiltrate through brain tissue) are composed of neoplastic astrocytes that may occasionally exhibit certain morphologic differences when observed microscopically. Gemistocytic astrocytes are characterized by eccentric nuclei and plump pink cytoplasm that superficially resembles the belly of a pregnant woman when viewed from above. Neoplasms that are predominantly composed of... Continue Reading →
Pilocytic Astrocytoma (PA) characteristically exhibits biphasic morphology featuring densely fibrillar, compact regions alternating with loosely-cohesive microcystic or myxoid areas; the latter is pictured here. Diagnosis can be difficult, especially on small biopsies, but molecular testing can help. BRAF-KIAA1549 fusion occurs in about 70% of PAs, whereas BRAF V600E mutation occurs in about 5-10% of PAs.
Pilocytic astrocytoma is a circumscribed glioma (WHO Grade I) commonly found in children and young adults. Characteristic features include piloid cells with long, thin, hair-like cytoplasmic processes and a myxoid background, which are both seen here in this medium power image of a cytologic smear preparation performed during intraoperative consultation.
Astrocytes are star-shaped glial cells that comprise a large proportion of brain tissue. Non-neoplastic reactive astrocytes can sometimes be difficult to differentiate from the neoplastic astrocytes of glial tumors called astrocytomas. This GFAP stain highlights the key morphologic differences between the star-shaped and widely spread-out non-neoplastic reactive astrocytes compared to the neoplastic astrocytes in this glioblastoma, which exhibit crowding and severe variation in... Continue Reading →
Giant Cell Glioblastoma, also called magnocellular or monstrocellular glioblastoma, is characterized by atypical cells that are extremely large, especially when compared to the non-neoplastic inflammatory cells seen on the left side of the image. The tumor has increased number of dividing cells, including typical mitotic figures (bottom left arrow) and atypical or granular mitoses (bottom... Continue Reading →
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Glioblastomas are high grade astrocytomas that often exhibit microvascular proliferation, characterized by atypical hypertrophic and hyperplastic endothelial cells. A mitotic figure within a proliferating endothelial cell is present in the top right corner of the image.
Learn about basic histopathologic diagnosis of diffuse astrocytomas. https://www.youtube.com/watch?v=sm764936sIg&feature=share