MR imaging characteristics of pilomyxoid astrocytomas.
OBJECTIVE
Pilomyxoid astrocytoma (PMA) is a recently described tumor that typically occurs in the chiasmatic-hypothalamic region in young children and has unique histopathologic and clinical characteristics. These tumors have been previously diagnosed as pilocytic astrocytoma (PA). PMA appears to have a higher rate of recurrence and CSF dissemination than typical PA.


METHODS
We analyzed MR findings in four patients with PMA and compared them with those of typical chiasmatic-hypothalamic PA.


RESULTS
MR findings of PMA were chiasmatic or hypothalamic enhancing solid tumor with hydrocephalus, highly homogeneous T2 signal intensity that extended into the deep white and gray matter, and CSF dissemination.


CONCLUSIONS
Larger series are needed before the MR imaging findings of chiasmatic or hypothalamic enhancing solid tumor with hydrocephalus, highly homogeneous T2 signal intensity extending into the deep white and gray matter, and CSF dissemination can be used in the differential diagnosis of such tumors.
Arslanoglu
Atilla
A
Department of Radiology, Johns Hopkins University, Baltimore, MD 21287, USA.
Cirak
Bayram
B
Horska
Alena
A
Okoh
James
J
Tihan
Tarik
T
Aronson
Leslie
L
Avellino
Anthony M
AM
Burger
Peter C
PC
Yousem
David M
DM
D001254:Astrocytoma / Q000175:diagnosis* / Q000473:pathology / Q000556:secondary; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007029:Hypothalamic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D009897:Optic Chiasm / Q000473:pathology; D019574:Optic Nerve Neoplasms / Q000175:diagnosis* / Q000473:pathology; D013120:Spinal Cord Neoplasms / Q000556:secondary