| Abstract: |
A 28-year-old man presented with a short history of headache, visual and aphasic speech disturbances. MR scans revealed a large, partly cystic, contrast-enhancing lesion of the left temporal lobe that upon microscopic examination was diagnosed as pleomorphic xanthoastrocytoma (PXA) with anaplastic features (WHO grade III). Remarkably, this tumor featured an unusual gliovascular, rosette-like histoarchitecture, which had previously been hypothesized to possibly indicate a greater likelihood of PXA recurrence. Indeed, only 14 months later, the patient presented with a recurrent lesion, which contained the previous histology, but now also featured a distinct fibrosarcoma-like component replete with numerous osteoclast-type giant cells. In addition, whereas eosinophilic granular bodies were plentiful at the lesion's periphery, numerous CD34 - positive satellite cells were found in the adjacent noninfiltrated cortex. Regarding the origin of this recurrent tumor and in reflection of its composition of distinct PXA as well as sarcomatous components, the diagnosis of a pleomorphic xanthoastrosarcoma, to be conceptually considered as a gliosarcoma subtype, was made.To our knowledge, this is an unprecedented case of sarcomatous transformation of a PXA. Particular attention should be given to gliovascular pseudopapillary structures in PXAs, the presence of which may potentially herald a more aggressive clinical behavior. © 2008 The Authors. |
