ASPSCR1::TFE3-rearranged renal cell carcinomas: clinicopathologic, molecular, and survival analysis of 30 cases.

The cohort demonstrated an overwhelming female predominance, with a median age of 23.6 years.

Immunohistochemically, all tested tumors showed nuclear TFE3 positivity, with variable PAX8 expression, weak or absent staining for epithelial markers (CK7 and EMA), and negativity for melanocytic markers (HMB45 and Melan-A).

PD-L1 was positive in 4 of 18 cases.

Univariate analysis linked larger tumor size (> 4 cm), grossly solid appearance, tumor necrosis, psammoma bodies, microvascular tumor thrombi, high Ki-67 (≥ 5%), advanced stage (≥ III), and synchronous metastasis to worse prognosis.