Background: Renal transplant (RT) remains the optimal treatment for end-stage renal disease and early complications might be detected in the postoperative period to improve long-term outcomes. To this regard, contrast enhanced ultrasound (CEUS) could be utilized to evaluate RT functional recovery and potentially detect acute rejection (AR) and/or renal ischemia signs. Materials and methods: Observational study of 107 consecutive patients waitlisted for RT. Participants underwent conventional ultrasound (CUS) and color-doppler-ultrasound (CDUS) to evaluate resistive index of segmental and interlobar arteries and quantitative CEUS techniques recording the following perfusion parameters: peak intensity (PI-c), rising time (RT-c), area under (AUC-c) the time intensity curve (TIC), time to peak (TTP-c) and mean transit time (MTT-c). Results: CEUS parameters sensibility and specificity to predict AR in the early post-operative period resulted in: 90% and 69% for PI-c, 95% and 64% for RT-c, 85% and 65% for AUC-c. The overall diagnostic performance of these three CEUS parameters in comparison to the same in CUS and CDUS resulted in a sensitivity and specificity of 95% and 49%, versus 85% and 46%, respectively, therefore CEUS examination with the analysis of PI-c, RT-c and AUC-c values increases the diagnostic sensitivity in predicting AR by approximately 15–20% compared to CDUS and by 30–40% compared to CUS. Conclusion: CEUS could be routinely included in RT follow-up, as it shows to be a non-invasive helpful diagnostic tool for early detection of renal graft complications, selecting patients eventually in need of further confirmation.

A cancer of unknown primary site of origin (CUP) is a definition for neoplasms whose first—and unique—presentation is of a neck mass. The urgent need to identify and characterize the primary tumor imposes a precise, prompt, and individualized diagnostic pathway to best guide the treatment. For the aim of this work, 5323 patients were identified from case series ranging from the year 2016 to 2023, selecting, from the 605 total cases in 2019, the clinical cases that met the characteristics of a CUP, which concerned 28 individuals. The 5-year follow-up of the 28 patients examined in 2019 revealed that, in more than half of the patients, the site of onset of primary tumors could not be revealed. Of these, 9 patients were classified as being affected by a CUP, and 9 patients died of carcinoma of uncertain origin; in the remaining 10 patients, the investigations were able to reveal the primary tumor. The lack of identification of a primary tumor prevents the patient from being treated with a curative intent. The identification of the primary tumor is achieved through a pathway of investigations that involves several approaches from a multidisciplinary perspective. The contribution of imaging and its increasingly important role, along with the implementation of its techniques and technologies, help make certain diagnoses in less time.