Clinicopathologic features and pathogenesis of melanocytic colonization in atypical meningioma.

Only two prior cases of benign dendritic melanocytes colonizing a meningioma have been reported. We add a third case, describe clinicopathologic features shared by the three, and elucidate the risk factors for this very rare phenomenon. A 29 year-old Hispanic woman presented with headache and hydrocephalus. MRI showed a lobulated enhancing pineal region mass measuring 41 mm in greatest dimension. Subtotal resection of the mass demonstrated an atypical meningioma, WHO grade II, and the patient subsequently underwent radiotherapy. She presented 4 years later with diplopia, and MRI showed an enhancing extra-axial mass measuring 47 mm in greatest dimension and centered on the tentorial incisura. Subtotal resection showed a brain-invasive atypical meningioma with melanocytic colonization. The previous two cases in the literature were atypical meningiomas, one of which was also brain invasive. Atypical meningiomas may be at particular risk for melanocytic colonization as they upregulate molecules known to be chemoattractants for melanocytes. We detected c-Kit expression in a minority of the melanocytes as well as stem cell factor and basic fibroblast growth factor in the meningioma cells, suggesting that mechanisms implicated in normal melanocyte migration may be involved. In some cases, brain invasion with disruption of the leptomeningeal barrier may also facilitate migration from the subarachnoid space into the tumor. Whether there is low-level proliferation of the dendritic melanocytes is unclear. Given that all three patients were non-Caucasian, meningiomas in persons and/or brain regions with increased dendritic melanocytes may predispose to colonization. The age range spanned from 6 years old to 70 years old. All three patients were female. The role of gender and estrogen in the pathogenesis of this entity remains to be clarified. Whether melanocytic colonization may also occur in the more common Grade I meningiomas awaits identification of additional cases.

Early experience with formalin-fixed paraffin-embedded (FFPE) based commercial clinical genomic profiling of gliomas-robust and informative with caveats.

BACKGROUND: Commercial targeted genomic profiling with next generation sequencing using formalin-fixed paraffin embedded (FFPE) tissue has recently entered into clinical use for diagnosis and for the guiding of therapy. However, there is limited independent data regarding the accuracy or robustness of commercial genomic profiling in gliomas. METHODS: As part of patient care, FFPE samples of gliomas from 71 patients were submitted for targeted genomic profiling to one commonly used commercial vendor, Foundation Medicine. Genomic alterations were determined for the following grades or groups of gliomas; Grade I/II, Grade III, primary glioblastomas (GBMs), recurrent primary GBMs, and secondary GBMs. In addition, FFPE samples from the same patients were independently assessed with conventional methods such as immunohistochemistry (IHC), Quantitative real-time PCR (qRT-PCR), or Fluorescence in situ hybridization (FISH) for three genetic alterations: IDH1 mutations, EGFR amplification, and EGFRvIII expression. RESULTS: A total of 100 altered genes were detected by the aforementioned targeted genomic profiling assay. The number of different genomic alterations was significantly different between the five groups of gliomas and consistent with the literature. CDKN2A/B, TP53, and TERT were the most common genomic alterations seen in primary GBMs, whereas IDH1, TP53, and PIK3CA were the most common in secondary GBMs. Targeted genomic profiling demonstrated 92.3%-100% concordance with conventional methods. The targeted genomic profiling report provided an average of 5.5 drugs, and listed an average of 8.4 clinical trials for the 71 glioma patients studied but only a third of the trials were appropriate for glioma patients. CONCLUSIONS: In this limited comparison study, this commercial next generation sequencing based-targeted genomic profiling showed a high concordance rate with conventional methods for the 3 genetic alterations and identified mutations expected for the type of glioma. While it may not be feasible to exhaustively independently validate a commercial genomic profiling assay, examination of a few markers provides some reassurance of its robustness. While potential targeted drugs are recommended based on genetic alterations, to date most targeted therapies have failed in glioblasomas so the usefulness of such recommendations will increase with development of novel and efficacious drugs.

Multiple calcifying pseudoneoplasms of the neuraxis (MCAPNON): Distinct entity, CAPNON variant, or old neurocysticercosis?

We report a case of multiple calcifying pseudoneoplasms of the neuraxis (MCAPNON) with associated multifocal perivascular microcalcifications and vascular calcinosis. Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a very rare condition that may arise in extra-axial and occasionally, in intra-axial locations. Moreover, it is nearly always a solitary mass with only one case with two lesions reported. While the etiology and pathogenesis of CAPNON remains unclear, the histopathology findings of this entity have been well described. We report a case of a 62-year-old woman with 18 calcifying radiologic lesions involving bilateral cerebral hemispheres. Histologically, these lesions have features similar to that reported for CAPNON, including nodular calcification with fibro-osseous components and peripheral histiocytic reaction. The patient had a poorly documented diagnosis of neurocyticercosis 32 years prior, although without tissue confirmation. The lack of detectable cysticercus serum antibody titers, and absence of residual larval or cyst wall tissue render multifocal calcific involution of that parasite unprovable although still plausible. We also raise the possibility of a blood-brain barrier derangement and/or a metabolic disorder as an alternative etiology. Whether this case of MCAPNON shares the same pathogenesis as the usual solitary CAPNON is unclear.

A descriptive analysis of general surgery residency program directors in the United States.

BACKGROUND: Women remain underrepresented in surgery. We analyzed the demographics of general surgery program directors (PDs) and compared gender differences. METHODS: A search of online resources was conducted, including 344 general surgery residencies. RESULTS: 340 residencies were included. 261 PDs (76.8%) were male and 79 (23.2%) were female. Females were appointed at a younger age (p < 0.0001), were appointed sooner after residency (p < 0.0001) and have served similar term lengths compared to males (p = 0.556). There was no difference in academic position, fellowship training, or scholarly output between genders. Residencies with a female PD had a greater percentage of female residents (p = 0.04). CONCLUSION: General surgery PDs are predominately male with fellowship training; however the percentage of female PDs is similar to the percentage of practicing female general surgeons in the US. Gaining a better understanding of the characteristics of general surgery PDs can aid female surgeons in attaining academic leadership positions.

An Introduction to Hardware, Software, and Other Information Technology Needs of Biomedical Biobanks.

Biobanks support medical research by facilitating access to biospecimens. Biospecimens that are linked to clinical and molecular information are particularly useful for translational biomedical research. Tracking and managing the biospecimens and their associated data are therefore crucial tasks in the functioning of a biobank. Adequate computing hardware, efficient and comprehensive biobanking software, and cost-effective data storage are needed for proper management of biospecimens. As biobanks build up extensive stores of specimens and patient data, ethical considerations also inevitably arise. Herein, we describe some basic considerations for establishing a biobanking information technology infrastructure that a beginning biobanker needs. Finally, we also discuss trends and future needs in biobanking informatics.

An Introduction to Performing Immunofluorescence Staining.

Immunofluorescence (IF) is an important immunochemical technique that allows for detection and localization of a wide variety of antigens in different types of tissues of various cell preparations. IF allows for excellent sensitivity and amplification of signal in comparison to immunohistochemistry, employing various microscopy techniques. There are two methods available, depending on the scope of the experiment or the specific antibodies in use: direct (primary) or indirect (secondary). Here, we describe preparation of specimens preserved in different types of media and step-by-step methods for both direct and indirect immunofluorescence staining.