76‐YEAR‐OLD MAN WITH A CEREBELLAR LESION

We report a case of balloon cell melanoma metastatic to the cerebellum; the clear cell morphology prompted initial differential diagnostic considerations of metastatic renal cell carcinoma and hemangioblastoma in this site. To our knowledge this is only the second case of metastatic balloon cell melanoma to the CNS.     

A 14‐YEAR‐OLD GIRL WITH MULTIPLE TUMORS

Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytic tumor that usually occurs in the superficial cerebral hemispheres of children and young adult and has a favorable prognosis. We report a case of a 14‐year‐old girl with a recent history of sciatica and ataxic gait. Pre‐ and post‐contrast brain and spinal MRI revealed the presence of multiple solid lesions with a cystic component in the cerebellum and the spinal cord with a concomitant massive leptomeningeal involvement Histological and immunohistochemical findings were concordant with a final diagnosis of WHO grade II PXA. Even the biological indolent PXAs'' behavior, this is the third report in the literature of such an unusual multicentric PXA with leptomeningeal dissemination.     

33 YEAR‐OLD WOMAN WITH A LARGE SELLAR TUMOR

The authors describe a case of paraganglioma of the sellar region in a young female patient with loss of vision and headache. She presented with amaurosis, depression, anxiety and amenorrhea. Clinical and radiological impression was that it was a meningioma or pituitary adenoma. She received bromocriptine with no reduction of the lesion. She developed panhypopituitarism, but with normal levels of prolactin. It was resected and histological examination revealed nests of large cells with moderate nuclear pleomorphism, vesicular nuclei with occasional nucleoli. There were rare mitotic figures, but no necrosis. Immunohistochemistry was positive for synaptophysin, chromogranin A, and neuron‐specific enolase with a few sustentacular cells positive for S100. The Ki67 proliferation was 1‐2%. All pituitary hormonal antibodies were negative as well as GFAP, AE1/AE3, p53 and EMA. Paragangliomas affecting the sellar region are extremely rare and might be due to the presence of remnants of paraganglionic tissue or abnormal migration. The patient''s post‐operative diabetes insipidus remains under medical control.     

40‐YEAR OLD FEMALE WITH A SELLAR MASS

Pituicytoma is a rare, low‐grade neoplasm that originates in the neurohypophysis of the pituitary gland. We report the clinicopathologic features of a pituicytoma arising in a 40‐year‐old female who presented with menstrual disorder for 2 months, clinically suggestive of a pituitary microadenoma. The tumor was marked by a proliferation of elongated cells arranged in bundles and interlacing fascicles. The tumor demonstrated positive staining with S‐100 protein and patchy staining for glial fibrillary acid protein and Epithelial Membrane Antigen. The tumor did not stain with antibodies to Progesterone receptor and Neu‐n. An MIB‐1 labeling was lower than 1%. The tumor was subtotally resected and didn''t recur after the initial surgery.