Background: Mesothelioma of the tunica vaginalis testis (MTVT) is an exceedingly rare tumor. We performed a registry-based study on MTVT patient management and survival in Italy. Methods: Cases were extracted from the dataset of the Italian National Mesothelioma Registry. A descriptive analysis of patient characteristics, including asbestos exposure, clinical presentation, diagnostic work-up and therapeutic management, was performed. Overall survival was evaluated. We calculated hazard ratios (HR) and 95% confidence intervals (CI) for selected variables by fitting univariate and multivariable Cox models. Results: Overall, 104 patients with MTVT were included. Median age was 72 years (range 17–92). Epithelioid histotype was the most frequent. Previous asbestos exposure was identified in two thirds of cases. Data on diagnostic and therapeutic management were available for 74 patients (71%). The most frequent presentations were scrotal swelling/mass, hydrocele and inguinal pain. All patients underwent surgery, mostly with orchi-funicolectomy. Adjuvant therapy was administered to 15 patients (20%). Overall median survival was 26.2 months (95% CI 22.1–52.1); 3-, 5- and 10-year survival was 49%, 30% and 18%. Older age at diagnosis and presence of distant metastasis (HR 1.91, CI: 0.85–4.26) were negative prognostic factors. Adjuvant therapy was associated with higher mortality (HR 2.54, CI: 1.25–5.15), indicating a more advanced stage at diagnosis. Conclusions: Surgery remains the mainstay of treatment for MTVT; adjuvant therapy in our study did not improve outcome. Data from cancer registries are essential for rare cancers, but they should be integrated routinely with additional diagnostic and therapeutic information.

Background: Pericardial mesothelioma (PM) is an extremely rare cancer with a poor prognosis and no consensus on diagnostic and therapeutic management. We conducted a registry-based study on PM cases in Italy diagnosed between 1993 and 2021. Methods: Based on data from the Italian National Mesothelioma Registry (ReNaM), we performed a descriptive analysis of PM cases including clinical presentation, diagnostic work-up, asbestos exposure, and therapeutic management. Overall survival was calculated. Hazard ratios (HRs) and 95% confidence intervals (CI) for selected variables were estimated with univariate and multivariate Cox models. Results: We identified 72 cases (46 men and 26 women). Median age was 66 years (range 22–89). The most frequent histological subtypes were epithelioid and unspecified mesothelioma. Almost two-thirds of cases had been exposed to asbestos. The most common clinical presentation was pericardial effusion. Overall median survival was 2.8 months (95% CI 1.2–6.6) and older age at diagnosis was a negative prognostic factor. Clinical and treatment data were available for 47 patients (65%). Approximately one out of two patients underwent surgery (palliative, in one-third of cases). Adjuvant therapy was administered to seven patients (15%). In cases with treatment information, sarcomatoid subtype (HR 2.74, 95% CI: 1.06–7.06) was a negative prognostic factor; adjuvant therapy was associated with better survival (HR 0.38, 95% CI 0.14–1.02), but confounding by indication cannot be excluded. Conclusions: We confirmed the very poor prognosis of PM. An international network collecting PM cases with treatment information is needed to improve patient quality of life and survival.