TFE3-Rearranged Renal Cell Carcinoma With Osseous Metaplasia: A Case Report of a Rare Entity With an Unusual Finding

<i>TFE3</i>-rearranged renal cell carcinoma (RCC) is a rare subtype of renal tumor that typically affects the pediatric age group. Previous exposure to chemotherapy agents increases the possibility of having this subtype. Morphologically, it displays a broad spectrum of growth patterns, but it can be distinguished by the presence of melanin pigment or psammoma bodies. Osseous metaplasia is an uncommon morphological finding in this particular subtype, and it has been reported in two cases in the literature. We describe the third case of <i>TFE3</i>-rearranged renal cell carcinoma with osseous metaplasia in a healthy 13-year-old male, presenting with worsening abdominal pain and hematuria.