Clinical and Pathological Features of Renal Cell Carcinoma in Young Adults

This study aimed to describe the clinicopathological characteristics of renal cell carcinoma (RCC) in young adults (≤ 40 years) and reclassify tumour subtypes in accordance with the 2022 World Health Organization (WHO) classification, with exploratory assessment of outcome-related associations.

Individuals aged 40 years or younger who had been diagnosed with RCC were retrospectively evaluated. All cases were re-evaluated using the current WHO 2022 classification criteria and immunohistochemical markers. Demographic data; histological subtypes; surgical treatment methods; and patient outcomes, including recurrence and mortality, were reviewed.

Clear-cell RCC was the most common subtype (65.8%), followed by chromophobe RCC (20%) and papillary RCC (11.4%). A rare case of mucinous tubular and spindle cell carcinoma was identified. Tumour size and pathological stage significantly influenced the surgical modality; partial nephrectomy was more frequently performed in smaller tumours. Recurrence and mortality were primarily observed in patients treated with radical nephrectomy and those with adverse histologic features such as tumour necrosis and lymphovascular invasion.

This study provides a clinicopathological overview of RCC in young adults on the basis of 2022 WHO classification. Despite the exploratory nature of survival analyses due to limited events, the findings highlight the histological diversity and clinical features of RCC in this population.