Contributed by Valeria Barresi1, MD, Maria Caffo2, MD, Luana Licata1, MD, Filippo Flavio Angileri2, MD
1Departments of Human Pathology, and 2 Neurosciences, University of Messina, Italy
A 59-year old female referred to our hospital because of a cranial trauma following an episode of loss of consciousness. Clinical history was unremarkable expect for a headache of ten-days-duration. CT scan showed a retrosellar, rounded mass, isodense with the brain parenchyma, which measured 2,8 cm in maximum size. By MRI, the mass was likely extra-axial, showed intense and heterogeneous contrast enhancement. The mass compressed, though not infiltrated, the third ventricle (Figure 1). CT angiography showed close anatomical relationship with posterior cerebral arteries as well as with the apex of the basilar artery. At surgery, the lesion was reddish, highly vascularized and it infiltrated the hypothalamus. Due to close anatomical relationship with vital nervous and vascular structures, the lesion was submitted to only partial surgical resection.
Light microscopy of the surgical fragments with H&E stain disclosed a tumor composed of small cells with round hyperchromatic nuclei and clear cytoplasm (Figure 2) intermingled with large cells with dispersed chromatin and prominent nucleoli (Figure 2), within an eosinophilic fibrillary matrix. Sporadic large binuclear cells were also noticed (Figure 3). In addition, necrosis and vascular proliferation were observed (Figures 4 and 5), while no mitotic figures were found throughout the samples. At immunohistochemistry neoplastic cells were negative for GFAP, EMA, S100, CD34, olig-2 and IDH1 (Figure 5), while diffuse positive staining for synaptophysin was evidenced (Figure 6). Immunoreactivity for NSE, chromogranin and CD56 was also noted in the neoplastic cells. Ki-67 proliferation index was 3%. What is your diagnosis?