Pleomorphic xanthoastrocytoma

DNT, dysembryoplastic neuroepithelial tumor EMA, epithelial membrane antigen GEAR glial fibrillary acidic protein PXA, pleomorphic xanthoastrocytoma Syn, synaptophysin. 

Pleomorphic xanthoastrocytoma Pleomorphic cells are often vacuolated GFAP (S) type IV collagen (S) Leptomeninges cerebral cortex... 

FIGURE 20.17 Pleomorphic xanthoastrocytoma. Round lipid vacuoles are visible in pleomorphic astrocytes with H E in this particular specimen. Note that nuclear to cytoplasmic ratios are low, chromatin is finely granular, and nuclear membranes have gentle curves despite the large pleomorphic nuclei and nucleoli. 

Pleomorphic xanthoastrocytoma is a supratentorial astrocytoma that often involves both the leptomeninges and cerebral cortex (see Table 20.5). ° It has a more distinct margin with brain than most astrocytomas (see Fig. 20.1 OB). Its fibrillarity and its pleomorphic, hyaline, lipid-laden, and multinucleated cells are clues to its diagnosis (Fig. 20.17). Intracellular lipid content and protein granular degeneration vary from abundant to absent in individual tumors. 

FIGURE 20-18 This pleomorphic xanthoastrocytoma does not overexpress epidermal growth factor receptors (A). Rare cells overexpress p53 (B). 

Powell SZ, Yachnis AT, Rorke LB, et al. Divergent differentiation in pleomorphic xanthoastrocytoma Evidence for a neuronal element and possible relationship to ganglion cell tumors. Am J Surg Pathol. 1996 20 80-85. 

Kaulich K, Blaschke B, Numann A, et al. Genetic alterations commonly found in diffusely infiltrating cerebral gliomas are rare or absent in pleomorphic xanthoastrocytomas. J Neuropathol Exp Neurol. 2002 61 1092-1099. 

Martinez-Diaz H, Kleinschmidt-DeMasters BK, Powell SZ, et al. Giant cell glioblastoma and pleomorphic xanthoastrocytoma show different immunohistochemical profiles for neuronal antigens and p53 but share reactivity for class III beta-tubulin. Arch Pathol Lab Med. 2003 127 1187-1191. 

---