Man Bin Yim

Immunohistochemical analysis for histopathological subtypes in pediatric medulloblastomas

Medulloblastomas occurring in children represent a histological spectrum of varying anaplasia and nodularity. In order to determine whether immunohistochemical markers might be useful parameters in subclassifying these tumors, 17 pediatric medulloblastomas, including nine diffuse/non‐anaplastic, four diffuse/anaplastic, three nodular/non‐anaplastic and one nodular/anaplastic subtypes, were studied. In the present report, we investigate the expression of neural cell adhesion molecule (NCAM), nerve growth factor receptor (NGFR), neurofilament (NF), synaptophysin (SYN), glial fibrillary acidic protein (GFAP), S100, Bcl‐2, and Ki‐67 by using the immunohistochemistry against specific antibodies. This study showed that NGFR, NF, GFAP and S100 were not detected in anaplastic subtypes of medulloblastomas (0/5), while non‐anaplastic subtypes were mainly expressed within the nodules. All 17 tumors were reactive for NCAM, SYN and Bcl‐2. In addition, Ki‐67 labeling indices for anaplastic subtypes (39.0 ± 7.42%) were significantly higher than that of non‐anaplastic medulloblastomas (11.4 ± 8.04%; P < 0.0001). These results suggest that immunohistochemical markers are a useful adjunct in characterizing subtypes of pediatric medulloblastomas.

Giant intracranial varix arising from an arteriovenous fistula

A case of a giant intracranial varix arising from an arteriovenous (AV) fistula is reported. This 16 year old boy presented with a sudden onset of headache and dizziness. The patient had suffered from intermittent seizure attacks since the age of 4. Brain computed tomography (CT), taken 2 years prior to admission, showed compression of the quadrigeminal plate by a suspicious mass lesion. His brain CT, magnetic resonance imaging (MRI), and cerebral angiography on admission demonstrated a giant varix with evidence of haemorrhage in the cerebellum. The varix was fed from branches of the posterior cerebral artery and drained through a dilated vein into the vein of Galen. It was resected surgically. Surgery and/or endovascular obliteration of the AV fistula is required because the varix which develops from an AV fistula can enlarge and rupture.