Browsing by Author "Monaco, Gina N."

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    The role of the immune system in brain metastasis
    (Current Neurobiology, 2019-07) Leibold, Adam T.; Monaco, Gina N.; Dey, Mahua; Neurosurgery, IU School of Medicine
    Metastatic brain tumors are the most common brain tumors in adults. With numerous successful advancements in systemic treatment of most common cancer types, brain metastasis is becoming increasingly important in the overall prognosis of cancer patients. Brain metastasis of peripheral tumor is the result of complex interplay of primary tumor, immune system and central nervous system microenvironment. Once formed, brain metastases hide behind the blood brain barrier and become inaccessible to chemotherapies that are otherwise successful in targeting systemic cancer. The approval of immune checkpoint inhibitors for several common cancers such as advanced melanoma and lung cancers brings with it the opportunity and obligation to further understand the mechanisms of immunosuppression by tumors that spread to the brain as well as the interaction between the brain environment and tumor microenvironment. In this review paper we define the central role of the immune system in the development of brain metastases. We performed a comprehensive review of the literature to outline the molecular mechanisms of immunosuppression used by tumors and how the immune system interacts with the central nervous system to facilitate brain metastasis. In particular we discuss the tumor-type-specific mechanisms of metastasis of cancers that preferentially metastasize to the brain as well as the therapies that effectively modulate the immune response, such as immune checkpoint inhibitors and vaccines.
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    A Systematic Review of Sellar and Parasellar Brown Tumors: An Analysis of Clinical, Diagnostic, and Management Profiles
    (Elsevier, 2019-12) Alwani, Mohamedkazim M.; Monaco, Gina N.; Harmon, Sydney M.; Nwosu, Obi I.; Vortmeyer, Alexander O.; Payner, Troy D.; Ting, Jonathan; Otolaryngology -- Head and Neck Surgery, School of Medicine
    Objective To systematically review and analyze clinical, diagnostic, and management trends in sellar and parasellar brown tumors reported in existing literature. Methods In this systematic review, PubMed, Ovid MEDLINE, Scopus, and Google Scholar databases were searched for reported cases of sellar/parasellar brown tumors. Relevant titles and abstracts were screened in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. Articles meeting inclusion criteria were subjected to data extraction, summarization, and analysis. A rare case of parasellar brown tumor was also presented. Results Eight reports (including the current report) were eligible for inclusion. Mean patient age was 42.75 years. Reported symptoms included visual disturbances (n = 6), headache (n = 5), fatigue (n = 3), nausea/vomiting (n = 2), chest pain (n = 1), neck pain (n = 1), and dysphagia (n = 1). In cases where computed tomography findings were provided (n = 6), lesions were noted to be expansile and lytic. Lesions were hyperintense on T2-weighted magnetic resonance imaging (66.7%) and demonstrated contrast enhancement (83.3%). Histology unanimously showed multinucleated giant cells in a fibrovascular connective tissue stroma. Dramatic symptom resolution was noted in all patients who underwent resection of the sellar/parasellar brown tumor (n = 4; 50%). Conclusions Sellar/parasellar brown tumors are a rare, tertiary manifestation of hyperparathyroidism and can be elusive to diagnose. Diagnosis requires a high index of clinical suspicion in addition to comprehensive biochemical testing, imaging, and histopathologic analysis. Surgical extirpation is favored in cases where the lesion is causing compressive symptoms, or if it is unresponsive to management of hyperparathyroidism.