Cellular solitary fibrous tumor (hemangiopericytoma) with anaplasia at cerebellopontine angle--a case report.
Cellular solitary fibrous tumor is currently considered a synonym for hemangiopericytoma, as it became increasingly clear that the morphological and immunohistochemical features that separate these two entities have become tenuous, and evidence for a unifying concept has emerged. Furthermore, as no evidence of pericytic differentiation is given in most cases of hemangiopericytoma, this diagnostic term is waning in popularity. We present here a case of cellular solitary fibrous tumor in a 22-year-old man. Neuroimaging revealed a right cerebellopontine angle tumor. Most of the tumor was cellular although some less cellular areas were seen. Sinusoidally dilated large vessels, including staghorn type, were seen. Nuclear pleomorphism and increased mitotic activity (5 mitosis/10 high power field) were regarded as evidence of anaplasia. Diffuse CD34 immunoreactivity and focal positivity for Factor XIIIa were seen in the tumor, which was negative for EMA and S100. The tumor also displayed rich reticulin network. Solitary fibrous tumor at cerebellopontine angle is rare, and 20 such cases (five reported as hemangiopericytoma) have been reported in the English literature.
Department of Pathology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA.
Jianying
J
Zeng
Patricia
P
Ogera
Ethan A
EA
Benardete
Anthony D
AD
Nicastri
Chandrakant
C
Rao
D000708:Anaplasia; D014408:Biomarkers, Tumor / Q000378:metabolism; D002467:Cell Nucleus / Q000473:pathology; D002528:Cerebellar Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D002530:Cerebellopontine Angle / Q000473:pathology*; D026122:Factor XIIIa / Q000378:metabolism; D006393:Hemangiopericytoma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008938:Mitosis; D016896:Treatment Outcome; D055815:Young Adult
D014408:Biomarkers, Tumor; D026122:Factor XIIIa