Decreasing trend in thyroid cancer incidence: a study from central Italy (2007-2019).

PURPOSE: Due to overdiagnosis, the incidence of thyroid cancer (TC) has increased in high-income countries, including Italy. Efforts have been made to address this issue since the mid-2010s, but more information is needed about how TC incidence has changed. We aim to examine the trend in TC incidence in the Lazio Region (central Italy) and assess the impact of the 2014 Italian Consensus for the Classification and Reporting of Thyroid Cytology (ICCRTC) to identify potential changes in TC diagnosis. METHODS: To identify TC cases, we conducted a population-based study (period 2007-2019) using the data from the Lazio Region Cancer Registry (5.8 million residents). We calculated the annual age-standardized incidence rates of TC for both sexes and analyzed the impact of ICCRTC on monthly incidence rates using segmented linear regression applied to interrupted time-series (ITS). RESULTS: Throughout the 13 years, there was a significant decline in TC annual incidence rates, more pronounced in females. Our results are consistent with reports from outside Europe (United States and South Korea). Following ICCRTC implementation in 2014, a step-change reduction in both sexes was revealed. CONCLUSIONS: Our study indicates a significant decrease in the incidence of TC, particularly among females. The ITS analysis highlights the possible role of ICCRTC in reducing overdiagnosis. As the Lazio Region reflects the Italian population in terms of various demographic, health, and lifestyle indicators, our findings can be applicable at the national level.

Metastatic upper tract urothelial carcinoma with nest-like features presenting as malignant pleural effusion.

Metastatic urothelial carcinoma is a rare cause of pleural effusions. We report a case of urothelial carcinoma of the upper urinary tract in an oldest-old male patient, a smoker, with situs inversus totalis, that presented uniquely with malignant pleural effusion at presentation without evidence of a primary tumor on imaging. Cytological smears of the massive left pleural effusion revealed epithelioid neoplastic cells arranged in short cords, small-to-large clusters, and raspberry-like morules, mimicking mesothelioma; cell block preparations highlighted the presence of tubules and nest-like structures. The tumor cells showed a high nuclear-to-cytoplasmic ratio, nuclear grooves, and mitotic figures. Cytomorphologic features coupled with the immunophenotype of neoplastic cells (p63, GATA3, and uroplakin II positive) allowed the diagnosis of metastatic urothelial carcinoma and a possible nested subtype. These findings were supported by a total body computed tomography (CT) showing no evidence of a mass in the bladder or elsewhere in the urinary tract but a concentric parietal thickening of the proximal left ureter, suggesting malignancy. To our knowledge, a malignant effusion as a primary manifestation of urothelial carcinoma with nest-like features originating in the upper urinary tract has never been described previously. Our case focuses on the value of cell block in the working-up of neoplastic effusions by revealing the architectural pattern of an uncommon malignancy and the correlation between cytopathology and imaging gross findings to reach an accurate diagnosis.