Karen S. SantaCruz

Vaccination for Invasive Canine Meningioma Induces in Situ Production of Antibodies Capable of Antibody-Dependent Cell-Mediated Cytotoxicity

Malignant and atypical meningiomas are resistant to standard therapies and associated with poor prognosis. Despite progress in the treatment of other tumors with therapeutic vaccines, this approach has not been tested preclinically or clinically in these tumors. Spontaneous canine meningioma is a clinically meaningful but underutilized model for preclinical testing of novel strategies for aggressive human meningioma. We treated 11 meningioma-bearing dogs with surgery and vaccine immunotherapy consisting of autologous tumor cell lysate combined with toll-like receptor ligands. Therapy was well tolerated, and only one dog had tumor growth that required intervention, with a mean follow up of 585 days. IFN-γ-elaborating T cells were detected in the peripheral blood of 2 cases, but vaccine-induced tumor-reactive antibody responses developed in all dogs. Antibody responses were polyclonal, recognizing both intracellular and cell surface antigens, and HSP60 was identified as one common antigen. Tumor-reactive antibodies bound allogeneic canine and human meningiomas, showing common antigens across breed and species. Histologic analysis revealed robust infiltration of antibody-secreting plasma cells into the brain around the tumor in posttreatment compared with pretreatment samples. Tumor-reactive antibodies were capable of inducing antibody-dependent cell-mediated cytotoxicity to autologous and allogeneic tumor cells. These data show the feasibility and immunologic efficacy of vaccine immunotherapy for a large animal model of human meningioma and warrant further development toward human trials.

Occurrence of DNET and other brain tumors in Noonan syndrome warrants caution with growth hormone therapy

Noonan syndrome (NS) is an autosomal dominant developmental disorder caused by mutations in the RAS‐MAPK signaling pathway that is well known for its relationship with oncogenesis. An 8.1‐fold increased risk of cancer in Noonan syndrome has been reported, including childhood leukemia and solid tumors. The same study found a patient with a dysembryoplastic neuroepithelial tumor (DNET) and suggested that DNET tumors are associated with NS. Herein we report an 8‐year‐old boy with genetically confirmed NS and a DNET. Literature review identified eight other reports, supporting the association between NS and DNETs. The review also ascertained 13 non‐DNET brain tumors in individuals with NS, bringing to 22 the total number of NS patients with brain tumors. Tumor growth while receiving growth hormone (GH) occurred in our patient and one other patient. It is unknown whether the development or progression of tumors is augmented by GH therapy, however there is concern based on epidemiological, animal and in vitro studies. This issue was addressed in a 2015 Pediatric Endocrine Society report noting there is not enough data available to assess the safety of GH therapy in children with neoplasia‐predisposition syndromes. The authors recommend that GH use in children with such disorders, including NS, be undertaken with appropriate surveillance for malignancies. Our case report and literature review underscore the association of NS with CNS tumors, particularly DNET, and call attention to the recommendation that clinicians treating NS patients with GH do so with awareness of the possibility of increased neoplasia risk.

Successful treatment of pituitary carcinoma with concurrent radiation, temozolomide, and bevacizumab after resection

The optimal treatment of pituitary carcinomas (PC) is unknown. Treatment includes surgical resection, radiation, and more recently, temozolomide (TMZ). Pituitary adenomas have relatively high expression of vascular endothelial growth factor; therefore, bevacizumab, an antiangiogenic agent, has been used in a small number of aggressive or malignant pituitary tumors after recurrence. However, it has not been administered concurrently with other chemotherapeutic agents or combined with radiation therapy in PC. We present a 63-year-old man with an adrenocorticotropic hormone (ACTH)-secreting PC, causing visual loss. It was resected transsphenoidally. There were several notable factors placing the patient at high risk for recurrence including distant metastasis in the form of a pulmonary nodule. Morphologically, his tumor was a pituitary neoplasm with malignant histopathologic features. It had abundant mitotic figures and zones of necrosis. Six weeks post-surgery, the patient started concurrent chemoradiation, using combination therapy with TMZ and bevacizumab. TMZ was continued for 12 cycles in the adjuvant setting. The ACTH was effective as a serum-based tumor marker and normalized during treatment. The patient is alive, five years after diagnosis, with no recurrence to date. This is the first case of pituitary carcinoma treated successfully with concurrent chemoradiation therapy that combined TMZ and bevacizumab with a long-term follow up.

Changes in [18F]Fluorodeoxyglucose Activities in a Shockwave-Induced Traumatic Brain Injury Model Using Lithotripsy

We present a longitudinal study of cerebral metabolism using [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) in a rat model of shockwave-induced traumatic brain injury (SW-TBI). Anesthetized rats received 5 or 10 SW pulses to the right anterior lateral or dorsal frontal regions using SW lithotripsy. Animals were scanned for FDG uptake at baseline, 3 h post-injury, and 3 days post-injury, using a small animal PET/computed tomography (CT) scanner. FDG uptake at all time-points was quantified as the ratio of brain activity relative to peripheral activity in the left ventricle (LV) in the heart (Abrain/ALV) for the entire brain, each hemisphere, and four cortices (motor, cingulate, somatosensory, and retrosplenial). The mixed-designed models analysis of variance (ANOVA) for the hemispheric and global FDG uptake ratio showed a significant effect of the time-of-scan (p = 0.038) and measured region (p = 6.12e-09). We also observed a significant effect of the time-of-scan (p = 0.046) and measured region (p = 2.28e-09) for the FDG uptake ratio in four cortical regions. None of the measurements (global or local) showed a significant effect for the number of SW pulses (5 or 10) or SW location (lateral or dorsal frontal regions). Our data suggest that SW-TBI causes hypermetabolism on the impact side of the rat brain at 3 h post-injury compared with the baseline measurements. However, the increase in FDG uptake by day 3 post-injury was not significant. Further studies on post-TBI metabolic changes are needed to understand better the pathophysiology of the injury.

Fatal Granulomatous Amebic Encephalitis Due to Balamuthia mandrillaris in New Mexico: A Case Report

Balamuthia mandrillaris is a free-living amoeba that can cause granulomatous amebic encephalitis (GAE). We report a case in an individual with a history of alcohol abuse, cocaine use, and ditch water exposure. This is the first reported case of GAE due to B mandrillaris in New Mexico.

Inducing Different Brain Injury Levels Using Shock Wave Lithotripsy: Severity Model in Shock Wave-Induced Traumatic Brain Injury

To assess the feasibility of inducing different severities of shock wave (SW)‐induced traumatic brain injury (TBI) using lithotripsy.

Sellar Region Atypical Teratoid/Rhabdoid Tumors in Adults: Clinicopathological Characterization of Five Cases and Review of the Literature

Atypical teratoid/rhabdoid tumors (AT/RTs) are highly malignant CNS neoplasms that typically occur in children <2 years of age. These are characterized by high-grade histologic features and mutations of the INI1/SMARCB1 gene readily detected by loss of expression by immunohistochemistry. Among adults, the majority of AT/RTs occurs in the cerebral hemispheres. A small number of adult AT/RTs involving the sellar and suprasellar region reported in the literature suggest a distinct clinical course for this group. Here, we describe detailed clinical and genetic characterization of 5 adult patients with AT/RTs involving the sellar and suprasellar region, and provide a review of the available clinical and genetic features of 22 previously reported cases in order to help increase our understanding of this unusual entity.