Abstract

Renal angioleiomyoma is an exceptionally rare benign mesenchymal tumor, with fewer than five cases documented in the literature. Histologically, it is composed of proliferating smooth muscle cells intersected by branching, slit-like vascular channels and typically lacks significant epithelial components. Despite its benign nature, its morphological overlap with certain renal malignancies presents a diagnostic challenge. Notably, renal cell carcinoma with angioleiomyomalike stroma, a recently recognized variant of renal cell carcinoma, demonstrates a histologically and immunohistochemically similar stromal component. Although it generally exhibits a more indolent clinical course, there have been reports of lymph node involvement, underscoring its malignant potential. In this report, we present a case of renal angioleiomyoma and discuss the importance of distinguishing it from its malignant counterpart. Histopathological evaluation, supplemented by immunohistochemistry, plays a vital role in achieving a definitive diagnosis. Accurate differentiation is crucial to avoid overtreatment and to ensure appropriate clinical management. The overall prognosis is excellent, reflecting the inherent benign nature of renal angioleiomyoma. No routine long-term surveillance is required once a diagnosis is accurately confirmed. However, pathological overlap with renal cell carcinoma with angioleiomyoma-like stroma may necessitate selective follow-up in cases of diagnostic ambiguity. Improved awareness of renal angioleiomyoma helps ensure correct diagnosis and prevents confusion with malignant or other benign mesenchymal tumors that involve the kidney.