Malignant reninoma with pulmonary metastasis and ATRX mutation treated with olaparib: a case report of specialized treatment

We report a rare case of 32-year-old female with malignant reninoma complicated by pulmonary metastasis and ATRX mutation (p.G1964*, VAF 23.73%), initially misdiagnosed as renal pelvic carcinoma and treated with radical left nephrectomy and ureterectomy. The patient developed local recurrence and pancreatic head metastasis in January 2025, with stable disease achieved after radiotherapy, EP chemotherapy and toripalimab immunotherapy. Subsequent olaparib targeted therapy led to resolution of renal recurrent tumor, but progressive pancreatic lesion and persistent pulmonary metastasis were observed, suggesting tumor heterogeneity. This case demonstrates the value of NGS in screening actionable molecular targets for rare malignant reninoma; olaparib yields favorable local control for ATRX-mutated malignant reninoma based on synthetic lethality, while the differential response at metastatic sites underscores the need for exploring combination therapies to overcome tumor heterogeneity and drug resistance, providing a clinical reference for precision treatment of this rare disease.