Genomic analysis demonstrates that histologically-defined astroblastomas are molecularly heterogeneous and that tumors with MN1 rearrangement exhibit the most favorable prognosis.

Astroblastoma (AB) is a rare CNS tumor demonstrating abundant astroblastomatous pseudorosettes. Its molecular features have not been comprehensively studied and its status as a tumor entity is controversial. We analyzed a cohort of 27 histologically-defined ABs using DNA methylation profiling, copy number analysis, FISH and site-directed sequencing.

Utility of Pit-1 Immunostaining in Distinguishing Pituitary Adenomas of Primitive Differentiation from Null Cell Adenomas.

Pit-1 immunostaining is not routinely used in the characterization of pituitary adenomas, and its utility in distinguishing adenomas dedicated towards the lactotroph, somatotroph, and thyrotroph lineage from null cell adenomas warrants further evaluation. Pituitary adenomas that were negative for expression of a basic panel of hormonal markers (ACTH, prolactin, and growth hormone) were further evaluated for TSH, SF-1, and Pit-1 expression using a tissue microarray. Among the 147 identified pituitary adenomas that were negative for ACTH, prolactin, growth hormone, and TSH, expression of SF-1 was present in 68 cases (46%).

Morphological and molecular features of astroblastoma, including BRAFV600E mutations, suggest an ontological relationship to other cortical-based gliomas of children and young adults.

Background: Astroblastomas (ABs) are rare glial tumors showing overlapping features with astrocytomas, ependymomas, and sometimes other glial neoplasms, and may be challenging to diagnose.

Methods: We examined clinical, histopathological, and molecular features in 28 archival formalin-fixed, paraffin-embedded AB cases and performed survival analyses using Cox proportional hazards and Kaplan-Meier methods.

Results: Unlike ependymomas and angiocentric gliomas, ABs demonstrate abundant distinctive astroblastic pseudorosettes and are usually Olig2 immunopositive.

Osteolytic mass bridging two cervical vertebrae: Unusual presentation of a vertebral body hemangioma.

Vertebral hemangioma is the most common spinal axis tumor. This rare presentation of a vertebral hemangioma extended contiguously from one cervical vertebra to another, encasing the vertebral artery, and thereby mimicking other tumors of the spine. We discuss the differential diagnosis of bridging vertebral masses.

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.

Intraventricular metaplastic meningioma in a child: case report and review of the literature.

Childhood meningiomas are rare and display important differences from adult forms. We report the first case of an intraventricular metaplastic meningioma arising in a child. A 7-year-old female underwent resection of an enhancing tumor arising within the left lateral ventricle.

Recurring osteoma within a calcium phosphate bone cement cranioplasty: case report.

Objective: We present a unique case of a recurrent osteoma within a cranioplasty performed with calcium phosphate bone cement.

Clinical Presentation: The patient is a 7-year-old boy who had initially undergone a craniotomy for resection of a frontal cranial tumor followed by a cranioplasty with artificial bone matrix. On routine follow-up evaluation 2 years later, the patient had a mass expanding from the cranioplasty.

Distinguishing chordoid meningiomas from their histologic mimics: an immunohistochemical evaluation.

Chordoid meningioma, World Health Organization grade II, is an uncommon variant of meningioma with a propensity for aggressive behavior and increased likelihood of recurrence. As such, recognition of this entity is important in cases that show similar morphologic overlap with other chondroid/myxoid neoplasms that can arise within or near the central nervous system. A formal comparison of the immunohistochemical features of chordoid meningioma versus tumors with significant histologic overlap has not been previously reported.

CNS T-cell lymphoma: an under-recognized entity?

The incidence of CNS lymphoma has increased significantly in the past 30 years, primarily in the elderly and immunocompromised. While T-cell lymphomas comprise 15-20% of systemic lymphomas, they comprise less than 4% of primary CNS lymphomas, suggesting that they may be under-recognized compared to their systemic counterparts. To investigate this, we studied brain biopsies from three patients who were diagnosed with T-cell lymphoma confined to the brain.

Gliosarcoma with melanocytic differentiation.

We present an unusual case of gliosarcoma containing numerous islands of well-differentiated melanocytes in a 65 year-old man. Melanocytic differentiation of medulloblastomas is well described, and it has also rarely been reported in low-grade glial neoplasms. Histologic features and immunophenotyping are helpful in differentiating divergent differentiation in a gliosarcoma from melanoma.

Contemporary morphologic definition of backwash ileitis in ulcerative colitis and features that distinguish it from Crohn disease.

Terminal ileum (TI) sections from 250 ulcerative colitis (UC) total colectomy specimens resected during 3 periods and endoscopic TI biopsy specimens from 100 contemporary chronic UC and 100 Crohn disease (CD) patients were reviewed. The respective proportions of cases resected during the 3 periods with moderately or markedly active cecal UC were 72%, 34%, and 2% and with moderate or marked backwash ileitis (BWI), 21%, 18%, and 0%. The activity level of BWI correlated with level of cecal UC.

Lysyl oxidase expression in bronchogenic carcinoma.

Background: Lysyl oxidase catalyzes a key step in the cross-linking of collagen and elastin in the extracellular matrix. Recent studies have documented differential lysyl oxidase expression in the stromal reaction to colon, breast, prostate, and lung cancer. The present study was undertaken to test the hypothesis that lysyl oxidase mRNA and protein expression decrease with advancing tumor stage in patients with bronchogenic carcinoma.

West nile virus encephalitis involving the substantia nigra: neuroimaging and pathologic findings with literature review.

West Nile virus has become a medically important arbovirus in the continental United States with its debut in 1999 in the New York City area. We present neuroimaging features and pathologic findings in 2 patients who were severely affected out of the more that 100 documented cases at our institution. Both patients showed striking involvement of the substantia nigra, a finding not previously reported for West Nile virus.