The pivotal role of neurosurgeons in transitional care: A comprehensive tertiary healthcare institution's experience.

PURPOSE: Transitional care (TC) is increasingly crucial, particularly in neurosurgery, where optimal follow-through of patients' care is paramount. Challenges of transition are exacerbated by the complexity of neurosurgical conditions, with pediatric and adult neurosurgery often managed separately by different attending neurosurgeons or in different institutions. While numerous models for transitioning have been proposed, several barriers persist, impeding successful transfer from pediatric to adult settings. Our review focuses on important roles neurosurgeons can play in facilitating successful transition, exploring some existing TC models, with emphasis on the benefits of maintaining a single provider. METHODS: Clinic visits data between 2019 to 2023 of patients between the ages of 16 to 26 was compiled retrospectively. Successful transition was defined as continued follow-up moving from pediatric to adulthood with lost to follow-up being that of unsuccessful transition. Age, diagnosis and whether patients were successfully transitioned or lost to follow-up were documented. RESULTS: 1829 neurosurgical patients between the ages of 16 to 26 were identified over 5 years. A snapshot review identified 78 adolescent patients deemed to require follow-up into adulthood. 13 patients had epilepsy, 32 central nervous system (CNS) tumors, 17 congenital conditions, 14 neurovascular, and 2 patients had idiopathic intracranial hypertension. All 78 were noted to have successfully transited into their adulthood (age 21 and beyond). Having the same providers; having pediatric and adult neurosurgery within the same institution, was the single most important factor in facilitating successful transition. CONCLUSION: Neurosurgeons in institutions, particularly those with experience and competencies in both pediatric and adult care, can serve as crucial anchors during the transitional period. At our institution, the implementation of this continuity of care model has demonstrated remarkable success. Institutions with both pediatric and adult services would be uniquely positioned to develop and implement effective transitional care.

AB039. Malignant transformation of intracranial germinoma to non-germinomatous germ cell tumors-incidence, treatment strategy and outcome: a case report and literature review.

BACKGROUND: Intracranial germ cell tumors are rare neoplasms seen mainly in children and adolescents. Compared to non-germinomatous germ cell tumors (NGGCTs), germinomas typically respond well to chemo-radiotherapy and portend a better prognosis. We report here a patient with intracranial germinoma which showed complete remission following chemo-radiotherapy but re-presented with malignant transformation to NGGCT thirteen years later. We then performed a literature review to understand the treatment strategy and outcome of this rare phenomenon. METHODS: Review of the patient's case note, followed by a literature review of the topic. RESULTS: A 13-year-old male presented with 6 weeks of polyuria and polydipsia. Imaging showed bifocal (suprasellar and pineal) lesions. Histology from an open biopsy diagnosed a germinoma. He underwent extended whole ventricular irradiation with local boost and chemotherapy, which led to complete resolution on imaging. Thirteen years later, he re-presented with headaches and diabetes insipidus. Imaging showed a new right frontal lesion with elevated serum beta-human chorionic gonadotropin (ß-hCG) and alpha-fetoprotein (AFP). The tumor was excised with histology confirming a mixed tumor comprising germinoma, yolk sac, and choriocarcinoma. A literature review returned eight case reports of malignant transformation of intracranial germinoma to NGGCTs, covering eight patients (seven males, and one female; aged 5-23 years old). Four had the primary tumor located in the pineal region, three in the suprasellar region, and one at both sites. Recurrence with malignant transformation occurred at a median of 24.5 months after initial diagnosis (range, 5 months to 14 years). Five patients had recurrences intra-abdominally, all of whom had a ventriculoperitoneal shunt (VPS) inserted during the treatment of the initial tumor. Of the remaining three intracranial recurrences, two were at the same site while one at a distant site. The most common histology was yolk sac tumor (five patients), followed by two each of immature teratoma, choriocarcinoma, and embryonal carcinoma (some were mixed germ cell tumors). Of those with intra-abdominal recurrence, four died within 2 months of diagnosis. Those with intracranial recurrences survived longer, with a median survival of 15 months, and one longer than 27 months. CONCLUSIONS: Malignant transformation to NGGCTs is rare. Relapse can occur intracranially, or in cases where VPS was present, intraabdominally. Outcomes following transformation were poor despite aggressive treatment, with those intra-abdominal recurrences faring much worse.

AB064. Two case reports & review of literature: perioperative surgical management of symptomatic large non-functioning pituitary masses in early pregnancy.

BACKGROUND: Pituitary masses during pregnancy pose many challenges, requiring inputs from multidisciplinary teams. Where surgery is required, such as in cases of impending pituitary apoplexy, timing must be carefully selected. Several case reports have suggested good outcome with surgery in later trimesters or postpartum. However, insufficient data exists on surgical strategies for such patients with severe visual symptoms in early pregnancy. We report two patients with pituitary masses requiring surgical excision. METHODS: Review of patients' notes and imaging, with literature review. RESULTS: A 35-year-old gravida 2 para 1 female at 9 weeks gestational age (GA) presented with chronic bitemporal hemianopia, with acute left eye blurring of vision, identified during a pre-employment screening test. Imaging revealed a 38 mm × 29 mm × 33 mm sellar mass with compression onto the optic chiasm. She had no significant hormonal imbalances other than hyperprolactinemia and newly diagnosed Hashimoto's thyroiditis. She underwent transsphenoidal resection, with histology showing pituitary adenoma with blood clots. Similarly, our second patient was a 37-year-old gravida 4 para 2 female at 12 weeks GA with worsening bitemporal hemianopia with a 25 mm × 21 mm × 18 mm sellar mass displacing and compressing the optic chiasm. After resection she had marked objective improvement in her vision, but developed diabetes insipidus, and final histology revealed pituicytoma. Preoperative considerations for timing of surgery include pituitary apoplexy or acutely worsening visual field deficit. The pituitary physiologically increases in size during pregnancy, which can compress the optic chiasm and worsen visual deficit. In the case of apoplexy, delayed identification can have devastating consequences. However, major surgery in the first trimester may increase spontaneous miscarriage. The effects of imaging investigations from radiation, or gadolinium contrast administration, are also uncertain. While surgical positioning remains unaffected, other intraoperative considerations include strictly avoiding hypotension and using pregnancy-safe agents. Postoperative considerations include correcting hormonal deficiencies of hypopituitarism, including acute central hypocortisolism, diabetes insipidus and interruption of gonadotrophin production which could negatively affect pregnancy. Fetal heart rate must also be assessed. CONCLUSIONS: Determining timing of surgery to ensure well-being of both mother and fetus involves a difficult balance of risks. In our two cases, a thorough discussion with multidisciplinary input was required to achieve good outcomes.

A Mouse Model to Study the Pathogenesis of γ-herpesviral Infections in Germinal Center B Cells.

CD30-positive germinal center (GC)-derived B cell lymphomas are frequently linked to Epstein-Barr Virus (EBV) infection. However, a suitable animal model for the investigation of the interplay between γ-herpesvirus and host cells in B cell pathogenesis is currently lacking. Here, we present a novel in vivo model enabling the analysis of genetically modified viruses in combination with genetically modified GC B cells. As a murine γ-herpesvirus, we used MHV-68 closely mirroring the biology of EBV. Our key finding was that Cre-mediated recombination can be successfully induced by an MHV-68 infection in GC B cells from Cγ1-Cre mice allowing for deletion or activation of loxP-flanked cellular genes. The implementation of PrimeFlow RNA assay for MHV-68 demonstrated the enrichment of MHV-68 in GC and isotype-switched B cells. As illustrations of virus and cellular modifications, we inserted the EBV gene LMP2A into the MHV-68 genome and induced constitutively active CD30-signaling in GC B cells through MHV-68 infections, respectively. While the LMP2A-expressing MHV-68 behaved similarly to wildtype MHV-68, virally induced constitutively active CD30-signaling in GC B cells led to the expansion of a pre-plasmablastic population. The findings underscore the potential of our novel tools to address crucial questions about the interaction between herpesviral infections and deregulated cellular gene-expression in future studies.