Brain Pathology Case of the Month - April 2016

Contributed by Hui-Yuan Su, MD1, Chia-Mao Chang , MD1, Kun-Bow Tsai.MD3,4, Yu-feng Su, M.D.1,2
Department of 1Neurosurgery, Kaohsiung Medical University Hospital, and 2Institute of Clinical Medicine,1Kaohsiung Medical University, Kaohsiung, Taiwan
Department of 3Pathology, Kaohsiung Municipal Hsiao-Kang Hospital and 4Department of Pathology, Kaohsiung Medical University, Kaohsiung, Taiwan.


CLINICAL HISTORY

This 32-year-old man without specific underlying disease suffered from intermittent headache for more than half a month. The pain was localized over left side temporal area and then transferred to left occipital area. It could be relieved with acetaminophen. However a severe headache episode, with repetitive vomiting, aroused him from sleep early one morning. He was sent to the emergency department with stable vital signs and clear consciousness. On examination, there was no anisocoria, limbs weakness, dysphasia, dysarthria, or palsy of cranial nerves.

Brain computed tomography showed intracerebral hemorrhage (ICH) in the left side temporal base with uncal herniation and compression on the mid-brain (Fig.1). Computed tomography angiography then showed a space-occupying lesion with abnormal vascularity-enhanced attenuation and prominent drainage vein depicted intracranially over the left temporal base (Fig. 2, 3). Conventional angiography later showed multiple feeding arteries from anterior choroidal artery and temporal polar artery (Fig. 4). Multiple small rapid venous contrast medium pooling showed shunting connection with basal vein of Rosenthal and vein of Labbe to straight sinus, transverse sinus and sigmoid sinus respectively (Fig. 5).

According to the serial image studies, arteriovenous malformation (AVM) was the considered diagnosis. Spetzler-Martin AVM grade IV was graded on the medium size 3.2 X 3.5 centimeters, the deep venous drainage, and the location over temporal eloquent area.

The AVM and the ICH was removed completely with left orbito-zygomatic-pterional craniotomy and trans-cortical approach. The intraoperative course was smooth. The location of the nidus was deep into the tip of the temporal lobe.

MICROSCOPIC PATHOLOGY

Histopathological examination revealed tangled proliferation of variable-sized vessels within the hypercellular tumor (Fig. 6). Compact proliferation of spindled or ovoid cells around the congested vessels in the hypercellular tumor is noted (Fig. 7). GFAP in the tumor cells around a vessel showed strongly positive reaction (Fig. 8). Ki-67 proliferative index was 35% (Fig. 9). What diagnosis or diagnoses can be made?

FINAL DIAGNOSIS


International Society of Neuropathology