Brain Pathology Case of the Month - February 2009

Contributed by Nicolas Dea MD2; Manuela Pelmus MD1; David Mathieu MD2; François Belzile MD3;
    Denis Bergeron MD3; Sylvie Gosselin MD4; Ana-Maria Tsanaclis MD1
1 Department of Pathology, 2 Service of Neurosurgery, 3 Department of Neuroadiology, 4 Department of Neurology
    Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Québec, Canada.


CLINICAL HISTORY

A 64 year-old man presented with multiple transient cerebral ischemic attacks progressing for a week consisting of right-sided hemiparesis. The patient had a history of squamous cell cancer of the pharynx managed by chemotherapy and radiotherapy 10 years earlier. Six years ago, he had a lingual recurrence of his cancer, for which he underwent a partial glossectomy with left cervical dissection.

Radiologic investigation revealed a subtotal stenosis of the left internal carotid artery without cerebral infarction (figures 1 and 2). In view of his prior history of surgery and radiation in the left cervical area, he was treated by percutaneous angioplasty and stenting. He was then asymptomatic for about 8 months when ischemic episodes began to recur. Repeat percutaneous left carotid angioplasty was performed for progression of the stenosis in the left common carotid artery, proximal to the initial stenotic stented area. After an additional seven months of being asymptomatic, he presented, once again, with right hemiparesis. A head CT scan revealed multiple hyperdense lesions in the left carotid artery territory. Contrast-enhanced MRI confirmed the presence of 15 hemorrhagic lesions restricted to that vascular territory (figure 3). These lesions were hypointense on T1WI and T2WI with mild focal gadolinium enhancement and showed no diffusion restriction. A carotid angiogram showed the patency of the left carotid axis. A FDG PET scan revealed no active systemic neoplasm and hypometabolic cerebral lesions.

A left frontal open biopsy was performed and 3 grouped lesions were removed and submitted for pathology.

PATHOLOGY

Gross examination of the specimen revealed dark brown fragments of intermediate consistency. Histopathological examination revealed a necrotic and hemorrhagic lesion formed by an irregular set of vascular channels (figure 4). These channels were lined by highly anaplastic cells with marked pleomorphism and numerous mitoses (figure 5). The chromatin content of the nucleus was highly variable. There was a voluminous vessel with endoluminal proliferation of neoplastic cells (figure 6). The tumor cells rested on a conjunctive tissue stroma. In addition, there were macrophages with hemosiderin-filled cytoplasm, indicating remote bleeding. The interface with the adjacent cerebral tissue was sharply demarcated and this tissue showed a mild hypercellularity in the form of a significant reactive gemistocytic astrocytosis.

Tumor cells revealed a strong positive reaction for CD31 and CD34. The reaction for factor VIII was positive but more delicate. Reticulin surrounded vascular channels and some actin positivity was noted in the vessels walls. Immunostaining for GFAP, EMA, Melan-A and HMB-45 did not elicit any reaction. A positive reaction for GFAP was noted in the peripheral reactive astrocytosis.

FINAL DIAGNOSIS


International Society of Neuropathology