Pleomorphic xanthoastrocytoma: report of two cases with unconventional clinical presentations.

AIMS: Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytic neoplasm with a relative circumscribed architecture that typically arises superficially in the cerebral hemispheres of teenagers and young adults. Our aim is to highlight unconventional clinical presentations of this distinct neoplasm. MATERIALS AND METHODS: We report two cases of PXA with unconventional clinical features, including clinical, pathologic, and immunohistochemical features. RESULTS: The first case developed in the left frontal lobe of a 20-year-old female with neurofibromatosis type 1 (NF1). Focal anaplastic features were present. The neoplastic cells were immunoreactive for GFAP, S-100 protein and focally for synaptophysin, with a MIB-1/Ki-67 proliferative labelling index of 16%. The second case developed in a 39-year-old female as a suprasellar neoplasm. The neoplastic cells expressed GFAP, S-100 protein and focally CD34. The adenohypophysis was positive for synaptophysin and pituicytes for TTF1. Molecular studies were negative for BRAF (V600E) mutation in both cases. CONCLUSION: PXA is a distinct circumscribed neoplasm that may present in unexpected locations or clinical backgrounds. Neuropathologists must be aware of these unconventional presentations in order to provide a precise diagnosis leading to appropriate treatment.

Successful treatment of recurrent primary sclerosing cholangitis after orthotopic liver transplantation with oral vancomycin.

Primary sclerosing cholangitis (PSC) is a progressive, cholestatic disease of the liver that is marked by inflammation of the bile ducts and damage to the hepatic biliary tree. Approximately 60-70% of patients also have inflammatory bowel disease and progression of PSC can lead to ulcerative colitis and cirrhosis of the liver. Due to limited understanding of the etiology and mechanism of PSC, the only existing treatment option is orthotopic liver transplantation (OLT); however, recurrence of PSC, after OLT is estimated to be between 5% and 35%. We discuss the successful treatment of a pediatric patient, with recurrent PSC, after OLT with oral Vancomycin.

Intramedullary papillary ependymoma with choroid plexus differentiation and cerebrospinal fluid dissemination to the brain.

This 8-year-old girl presented with a papillary ependymoma in the thoracic spinal cord. Resection was followed by recurrence at the primary site and later in the lumbosacral thecal sac, followed by cerebrospinal fluid dissemination to the brain approximately 5 years after her initial presentation. The tumor showed cytological and immunohistochemical features overlapping those of classic ependymomas and choroid plexus tumors similar to those seen in uncommon supratentorial papillary ependymomas, also known as papillary tumors of the pineal region. The histopathological and clinical courses of this rare spinal papillary ependymoma exhibiting mixed ependymal and choroid plexus-like differentiation are discussed.