The role of macrophages in the growth and the progression of tumors has been extensively studied in recent years. A large body of data demonstrates that macrophage polarization plays an essential role in the growth and progression of brain tumors, such as gliomas, meningiomas, and medulloblastomas. The brain neoplasm cells have the ability to influence the polarization state of the tumor associated macrophages. In turn, innate immunity cells have a decisive role through regulation of the acquired immune response, but also through humoral cross-talking with cancer cells in the tumor microenvironment. Neoangiogenesis, which is an essential element in glial tumor progression, is even regulated by the tumor associated macrophages, whose activity is linked to other factors, such as hypoxia. In addition, macrophages play a decisive role in establishing the entry into the bloodstream of cancer cells. As is well known, the latter phenomenon is also present in brain tumors, even if they only rarely metastasize. Looking ahead in the future, we can imagine that characterizing the relationships between tumor and tumor associated macrophage, as well as the study of circulating tumor cells, could give us useful tools in prognostic evaluation and therapy. More generally, the study of innate immunity in brain tumors can boost the development of new forms of immunotherapy.

The basement membrane collagen IV-degrading matrix metalloproteinases -2 and -9 (MMPs) are most often linked to the malignant phenotype of tumor cells by playing a critical role in invasion, metastasis, angiogenesis, and vasculogenesis. We verified the activity of these two MMPs in the sera of patients affected by brain tumors (20 gliomas, 28 meningiomas and 20 metastasis) by zymography. The sera of 25 healthy volunteers with no concomitant illnesses were used for controls. Zymography showed four dominant gelatinolytic bands of 240, 130, 92 (MMP-9) and 72 (MMP-2) kDa. No statistically significant variations of MMP-2 proteolytic activity between patients and healthy individuals were observed. On the contrary, MMP-9 (both monomeric and multimeric forms) lytic activities were significantly higher in tumors specimens compared to healthy controls (p < 0.001). Moreover, MMP-9 immunohistochemistry revealed: (1) a strong reactivity in neoplastic vessels of high-grade gliomas showing an inverse correlation with serum multimeric gelatinolytic activity; (2) a cytoplasmatic reactivity in meningiomas with a significantly increase in atypical meningioma compared with low-grade ones (p = 0.036); (3) a positive correlation between MMP-9 and Ki-67 (Sperman Rho coefficient r = 0.418 and p = 0.034). Our results suggest that serum and tissue MMP-9 might provide clinicians additional objective information in intracranial neoplasms. Finally, it should be possible to use MMP-9 as a target for new forms of therapy. Nevertheless, due to the small number of patients included in the study, the conclusion may not be transferable to the general population and therefore further evaluations are needed.

Patients suffering from Inflammatory Bowel Diseases (IBD) are at increased risk of developing cancers of the gastrointestinal tract (GI). Adenocarcinomas are the most commonly observed GI tumours in IBD, and occur through an in inflammation-driven pathway. A trend toward reduced risk of bowel cancers has been observed in IBD in recent years, presumably related to improved medical treatments. However, some cancers may be independent from active inflammation, probably originating from altered interactions between the extremely active immune system of IBD patients and environmental factors. Data concerning gastrointestinal stromal tumours (GIST) and carcinoids tumours (CaT) of the GI in IBD patients are scanty. We report our experience with these rare cancers, and provide the readers with an overview on the topic, focussing on distinguishing and peculiar features of GIST and CaT of the GI in IBD compared with other cancer types and with general population, and address the treatment of such challenging conditions. Available data do not support an increased risk of GIST in IBD patients, but GI CaT may be more commonly observed in Crohn's disease. However, the presentation of GIST and GI CaT is protean and does not seem to be associated with disease activity in the involved GI segment in IBD. Conversely, some evidences suggest a potential role of inflammation in sustaining GI CaT in IBD. Increased awareness, longer duration of disease, and improved diagnostic modalities should also be considered when evaluating the increasing trend of CaT in CD patients. Treatment of GIST and CaT is not dissimilar from that of non-IBD patients, but prompt suspicion and diagnosis are crucial to achieve optimal outcomes.

Extramedullary plasmacytoma is a rare neoplasm characterized by monoclonal proliferation of plasma cells outside bone marrow. It accounts for 4% of all non-epithelial sinonasal tumors. According to the literature, radiotherapy is the standard therapy for extramedullary plasmacytoma. However, the conversion rate of extramedullary plasmacytoma to multiple myeloma is reported to be between 11 and 33% over 10 years. The highest risk of conversion is reported during the first 2 years after diagnosis, but conversion has been noted up to 15 years after diagnosis. Once conversion to multiple myeloma is complete, less than 10% of patients will survive 10 years. We present three cases of sinonasal extramedullary plasmacytoma who underwent radiotherapy: a 61-year-old white man, a 60-year-old white man, and a 37-year-old white woman. We found long-term survival with stable disease in all three cases. The management of solitary extramedullary plasmacytomas of the sinonasal tract is not well established yet. However, the possibility of recurrence and progression to multiple myeloma requires a thorough follow-up protocol. Due to the absence of a standardized protocol for these tumors, we tried to design a tailored long-term follow-up scheme.