Dynamic Occlusion of Distal Ventriculoperitoneal Shunt Catheter after Infusion Port Placement: A New Shunt Malfunction

Shunt failure requiring reintervention remains a common complication of hydrocephalus treatment. Here, we report a novel cause of mechanical shunt obstruction in an adult patient: position-dependent intermittent occlusion via an infusion port catheter. A 51-year-old woman with a grade II oligodendroglioma presented in a delayed fashion following surgery with a pseudomeningocele. She underwent ventriculoperitoneal shunt placement due to communicating hydrocephalus, resolving her pseudomeningocele. Shortly thereafter, she underwent placement of a subclavian infusion port at an outside institution. Her pseudomeningocele returned. Imaging demonstrated close proximity of her port catheter to the shunt catheter overlying the clavicle. Her shunt was tapped demonstrating a patent ventricular catheter with normal pressure. She underwent shunt exploration after her pseudomeningocele did not respond to valve adjustment. Intraoperative manometry demonstrated head position-dependent distal catheter obstruction. Repeat manometry following distal catheter revision demonstrated normal runoff independent of position. Her pseudomeningocele was resolved on follow-up. To our knowledge, this is the only reported case of intermittent, position-dependent distal catheter obstruction. Shunted patients with concern for malfunction following subclavian infusion port placement should be evaluated for possible dynamic obstruction of their distal catheter when the two catheters are in close proximity along the clavicle

A rare giant mixed germ cell tumor of the pineal region with immature elements: Case report and review of the literature

The diagnosis and management of mixed intracranial germ cell tumors may be complicated by the diversity present within this tumor category. Mixed germ cell tumors demonstrate variable natural histories which may be altered by the inclusion of even the most minute immature histological components. We report the case of an 18-year-old male who presented with a 3-month history of progressive headache and nausea leading to lethargy. Imaging revealed a giant pineal region mass extending superiorly from the roof of the fourth ventricle into the lateral ventricle, with resultant obstructive hydrocephalus. No spinal lesions were noted. Following gross total resection, the patient experienced marked improvement. Pathologic analysis identified an uncommon tumor composition: mature teratoma (96%), immature teratoma (2%), and germinoma (2%). Guided by the immature component, chemotherapy and radiation were added post-operatively to provide this patient with the greatest chance of long-term survival. Intracranial pathology, including germ cell tumors, should be included in the differential for any young patient presenting with new and progressive headache and nausea. This case emphasizes the benefit of a multimodal approach to mixed germ cell tumors of the pineal region and the importance of careful pathologic review of all submitted material

Laser Interstitial Thermal Therapy Case Series: Choosing the Correct Number of Fibers Depending on Lesion Size

BACKGROUND: Laser interstitial thermal therapy (LITT) is being used for the treatment of recurrent glioblastoma multiforme (GBM). Lesions can be treated using 1 or multiple LITT fibers depending on the preference of surgeons. Usually, more fibers are needed for coverage of larger tumors. OBJECTIVE: To investigate and analyze how tumor size affected the number of LITT fibers used. METHODS: This is a retrospective review of patients undergoing treatment of recurrent GBM. Patients were treated with up to 4 LITT fibers for adequate tumor coverage. Patient demographics, tumor characteristics, length of stay, complications, and biopsy results were recorded. RESULTS: A total of 43 cases were treated using LITT, and of these cases, 31 consisted of contiguous lesions. We used more fibers to treat larger tumor volumes. On average, for each 5 cc of tumor volume, a fiber was added for proper coverage (P=.554). Complications and length of stay were similar across the groups (P=.378, P=.941). CONCLUSION: LITT can be used for the treatment of recurrent GBM. For each 5 cc of tumor volume, a LITT fiber can be added to the treatment plan

\u3ci\u3eDrosophila\u3c/i\u3e Muller F Elements Maintain a Distinct Set of Genomic Properties Over 40 Million Years of Evolution

The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D. erecta, D. mojavensis, and D. grimshawi F elements and euchromatic domains from the Muller D element. We find that F elements have greater transposon density (25–50%) than euchromatic reference regions (3–11%). Among the F elements, D. grimshawi has the lowest transposon density (particularly DINE-1: 2% vs. 11–27%). F element genes have larger coding spans, more coding exons, larger introns, and lower codon bias. Comparison of the Effective Number of Codons with the Codon Adaptation Index shows that, in contrast to the other species, codon bias in D. grimshawi F element genes can be attributed primarily to selection instead of mutational biases, suggesting that density and types of transposons affect the degree of local heterochromatin formation. F element genes have lower estimated DNA melting temperatures than D element genes, potentially facilitating transcription through heterochromatin. Most F element genes (~90%) have remained on that element, but the F element has smaller syntenic blocks than genome averages (3.4–3.6 vs. 8.4–8.8 genes per block), indicating greater rates of inversion despite lower rates of recombination. Overall, the F element has maintained characteristics that are distinct from other autosomes in the Drosophila lineage, illuminating the constraints imposed by a heterochromatic milieu

Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356

non present