Brain Pathology Case of the Month - March 2014

Contributed by Jane Cryan1, Sarah Power2, Francesca Brett1
Departments of Neuropathology1 and Neuroradiology2, Beaumont Hospital, Dublin 9, Ireland.


CLINICAL HISTORY

We present 2 cases of intraventricular hemorrhage (IVH) in young patients. Case 1 is a 33 year old man who presented with collapse after acute onset occipital headache. On admission to hospital brainstem activity was absent. CT brain (Fig. 1) showed a large acute intraventricular hemorrhage, underlying intraventricular mass and obstructive hydrocephalus. Autopsy examination confirmed massive intraventricular hemorrhage. Coronal section of the brain (Fig. 2) shows destruction of the diencephalon and underlying tumor fragments. Case 2 is a 28 year old woman who presented with recent onset headache. T1W MR post contrast (Fig. 3) showed an enhancing tumor involving the 3rd ventricle and right thalamus. She underwent burrhole biopsy during which there was significant intra-tumoral hemorrhage. She did not regain consciousness post-operatively and imaging confirmed a large thalamic hemorrhage.

MICROSCOPIC PATHOLOGY

The tumor in case 1 was composed of a monotonous population of small round cells with a fine vascular background (Fig. 4). Mitoses, palisaded necrosis and vascular proliferation were not seen. Tumor cells were positive with synaptophysin (Fig. 5), negative with GFAP (Fig. 6) and proliferation index as assessed by MIB-1 was almost 0%. The tumor in case 2 was composed of round cells in an eosinophilic background with mild atypia (Fig. 7). High grade features were not present. The immunoprofile was identical to that in case 1. Proliferation index as assessed by MIB-1was low (Fig. 8). What is your diagnosis for case 1? For case 2?

FINAL DIAGNOSIS


International Society of Neuropathology