Brain Pathology Case of the Month - December 2016

Contributed by Drew Pratt, MD1; Gautam U. Mehta, MD2; Hao-Wei Wang, MD, PhD1; Prashant Chittiboina, MD2; Martha Quezado, MD1
1Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
     2Surgical Neurology Branch, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland


A 47 year old woman from Honduras presented with severe headache and left eye pain. An initial evaluation by a local ophthalmologist revealed no significant findings. Diagnostic imaging at the time demonstrated a sellar mass lesion. She was commenced on cabergoline, but this was ceased due to nausea, vomiting, and tumor progression. Her headaches persisted and she subsequently developed left eye exophthalmos, ptosis, and ophthalmoplegia. Follow-up CT demonstrated significant growth of the mass and involvement of the left orbital apex and cavernous sinus. She was started on corticosteroids and it was recommended she seek care of this lesion at our center.

On arrival to the Clinical Center, the patient reported interval loss of vision in her left eye, left and right facial numbness in a V1-V2 distribution, epistaxis, and three episodes of altered consciousness associated with confusion and disorientation that were preceded by tenesmus. The patient denied nausea, vomiting, or galactorrhea. Neurologic examination revealed intact extraocular muscles and pupillary responses, as well as normal visual fields in the right eye. Physical examination revealed left eye ptosis, proptosis, nonreactive pupil, absence of vision, and complete ophthalmoplegia. The remainder of the neurologic exam was unremarkable. Pituitary hormone testing revealed no hormonal abnormalities. CT chest, abdomen, and pelvis showed no evidence of a primary cancerous lesion. Pre-surgical MR imaging of the brain and dedicated pituitary scan revealed a 2.6 x 3.9 x 3.2 cm heterogeneously enhancing mass on T1-weighted images in the sella turcica with erosion of the surrounding bone and extension into the cavernous sinuses bilaterally (Figures 1, 2 and 3). Complete encasement of the left internal carotid artery and superior extension abutting the optic chiasm were also noted.

The patient underwent a transsphenoidal approach for resection of the intrasellar component of the mass, with residual tumor in both cavernous sinuses. Tissue sent for intraoperative consultation showed an epithelioid neoplasm with atypical features. The specimen was sent for permanent histologic evaluation. Her postoperative course was initially unremarkable until day two when the patient experienced a right sixth nerve palsy manifesting as failure to abduct the right eye. An urgent CT of head was unremarkable. Ophthalmology and radiation oncology consultations were requested for possible cavernous sinus syndrome. She was treated emergently with radiation to the sellar region with good symptomatic response.


H&E sections showed a highly cellular epithelioid neoplasm with cohesive tumor cells in a nested and trabecular pattern with moderate to abundant amounts of cytoplasm, irregular nuclear contours, and prominent pink nucleoli (Figure 4). The tumor demonstrated high mitotic activity and frequent apoptosis. Immunohistochemistry revealed focal positive staining for AE1/AE3 (Figure 5), EMA (Figure 6), and was negative for GFAP, CD3, CD20, CD45, CD34, CD99, chromogranin, c-Kit, PLAP, ER, PR, MART-1, S-100, SMA, TTF-1, and brachyury. Focal positive staining for synaptophysin was seen. The proliferative index was high (MIB-1 staining >50%, Figure 7). Staining for INI1 is shown in Figure 8. What is your diagnosis?


International Society of Neuropathology