Eosinophilic solid and cystic renal cell carcinoma (ESC-RCC) is a novel and uncommon type of renal cell carcinoma, which has been recently recognized and introduced as a distinct entity in the WHO 2022 kidney tumor classification. Previously known as “unclassified RCC”, followed by “tuberous sclerosis complex (TSC)-associated RCC”, ESC-RCC is now a distinct category of kidney tumor, with its own name, with specific clinical manifestations, and a unique morphological, immunohistochemical and molecular profile. Due to its recent introduction and the limited available data, the diagnosis of ESC-RCC is still a complex challenge, and it is probably frequently misdiagnosed. The secret of diagnosing this tumor lies in the pathologists’ knowledge, and keeping it up to date through research, thereby limiting the use of outdated nomenclature. The aim of our case-based review is to provide a better understanding of this pathology and to enrich the literature with a new case report, which has some particularities compared to the existing cases.

In the present study, we analyzed Programmed Death Ligand-1 (PD-L1) expression in radical cystectomy (RC) specimens from patients with muscle-invasive urothelial carcinoma (UC), in order to assess any correlations with specific clinicopathological features and its potential prognostic value. A multi-institutional study was performed within the departments of urology and pathology at the Mureș County Hospital, Romania, and Centre Hospitalier Lyon Sud, France. Sixty-nine patients with MIBC were included, for whom tumor histology (conventional versus histological variant/differentiation), tumor extension (T), lymph node involvement (N), and distant metastases (M) were recorded. PD-L1 immunostaining was performed using the 22C3 clone and was interpreted using the combined positive score (CPS) as recommended (Dako Agilent, Santa Clara, CA, USA). Positive PD-L1 immunostaining was more prevalent among UCs with squamous differentiation compared to conventional UCs and trended towards an improved OS (p = 0.366). We found the T stage to be a risk factor for poor survival in PD-L1-positive patients (HR 2.9, p = 0.021), along with the N stage in PD-L1-negative patients (HR 1.98, p = 0.007). No other clinicopathological factor was found to be significantly associated with PD-L1 positivity. Thus, we confirm the need for PD-L1 immunostaining prior to initiating immune checkpoint inhibitor therapy for a more accurate assessment of the patients’ chances of responding to treatment.

Background/Objectives: UBC demonstrates a relatively low prevalence in patients under 50 years old. Our study aimed to compare the pathological characteristics of UBC in young and elderly patients and to assess the age-related variations in these characteristics. Methods: This retrospective study from January 2018 to December 2022 encompassed 762 patients with an initial diagnosis of UBC. To evaluate the pathological characteristics of UBC in young patients, compared to elderly patients, we divided our cohort using a cut-off age of 50 years. Additionally, to evaluate the age-dependent variations in these characteristics, we further stratified our patients into three age groups (≤50, 51–70, and >70 years old). Results: Of the 762 patients included in our study, 37 (4.86%) were young (≤50 years old), with a median age of 44 and a M:F ratio of 3.11:1. Conventional UC was the most common histology (86.5%). Regarding tumour grade, we noticed a higher prevalence of PUNLMP (10.8% versus 2.3%) and LGPUC (45.9% versus 37.1%) and a lower prevalence of HGPUC (43.2% versus 60%) and CIS (0% versus 0.6%) in young patients (p = 0.008). In this group, the pTa stage revealed a higher prevalence (64.9% versus 46.8%), while pT1 and pT2 showed a lower prevalence (32.1% versus 18.9% and 20.6% versus 16.2%) (p = 0.179). All results remained consistent when the cohort was stratified into three age groups, showing age-related variations (p = 0.001 and p = 0.089, respectively). Conclusions: In young patients, UBC tends to be of a lower grade and stage compared to elderly patients, and these characteristics demonstrate a gradual age-related stratification.