Multicentric pleomorphic xanthoastrocytoma (PXA; WHO grade II) with leptomeningeal dissemination.
Pleomorphic xanthoastrocytoma (PXA) was first described by Kepes and colleagues in 1979 (4). PXA is a rare neoplasm (to date, about 200 cases have been reported), accounting for less than 1% of astrocytic tumors that occurs on the surface of cerebral hemispheres of children and young adult (2). Typically, these tumors have a favorable prognosis and seizures are the most common presenting symptoms. Commonly, the site of presentation is supratentorial, but cerebellar lesions have also been described, mainly involving the cortex and leptomeninges (2, 3).
Histological features include marked cellular pleomorphism, variable cell lipidization, an abundant reticulin network and perivascular inflammatory cells. Although PXA appears malignant at first glance, mitosis and necrosis are usually absent. As a result, this nosological entity has been classified as a grade II tumor according to the WHO grading system, although an anaplastic variant and malignant potential have been described (1, 2, 5).
To our knowledge, this is the third case of typical PXA with disseminated disease reported in the literature (6, 7). Two other cases have been reported with leptomeningeal dissemination (6, 7) and only one case of metachronous multicentric PXA (in which lesions manifest themselves in succession after variable disease-free intervals) has been described (7). Our case is the first and the only one in which a disseminated and synchronous multicentric PXA has been observed. Hence, it was considered important to describe this unusual case in order to add further information regarding the spectrum of the presenting clinical features of this rare neoplasm.
Even the biological indolent behavior of PXAs, these cases should alert physicians that unusual subdural and multicentric dissemination could be observed in PXA patients.
Contributed by Marina Paola GARDIMAN, Matteo FASSAN, Enrico ORVIETO, Loredana IARIA, Milena CALDERONE, Rodica MARDARI, Domenico D'AVELLA, Giorgio PERILONGO