A rare right perirenal hemangioma mimicking a retroperitoneal "malignant lesion": Diagnostic and procedural challenges of an extra-renal vascular mass.

Perirenal hemangiomas are rare benign vascular tumors that can present as indeterminate retroperitoneal masses and mimic renal, adrenal, or soft-tissue malignancy. We report the case of a 60-year-old woman who was incidentally found to have a right perirenal mass adjacent to the kidney and adrenal gland. Due to concern for a possible sarcoma, core biopsy was performed and demonstrated a benign vascular neoplasm compatible with hemangioma. This case highlights the diagnostic challenge of rare perirenal hemangiomas and the importance of considering vascular lesions when planning biopsy of enhancing retroperitoneal masses.