Malignant rhabdoid tumor of kidney in an adult patient with positive family history of rhabdoid tumor: A case report and review of literature.

Introduction And Importance: Malignant rhabdoid tumor of kidney (MRTK) is almost exclusive to children. Only 10 cases of adult MRTK have been reported. Here, we present a case of MRTK in an adult patient and discuss its clinical findings, diagnostic challenges, and treatment outcome. We also perform literature review on this issue.

Case Presentation: Our patient was a 29-year-old woman presented with fever and hematuria. She also mentioned atypical teratoid/rhabdoid tumor of cerebellum in her deceased child. Initial diagnostic work up led to left partial nephrectomy with the pathology report of high grade undifferentiated tumor. Early tumor recurrence necessitated left radical nephrectomy with extensive excision of adjacent tissues. Pathology for second specimen considering disease course and family history was MRTK. Even though chemotherapy was administered, she died few months later due to multiple metastases.

Clinical Discussion: Although diagnosis is challenging in all 11 reported cases -including our case- of adult MRTK, immunohistochemistry (i.e., negative reaction for INI-1) in conjunction with clinical and radiological findings are the main tool to reach diagnosis. Treatment options are much more diverse, ranging from surgery to immunotherapy, tyrosine kinase inhibitors, chemotherapy, and combination of these modalities. Prognosis remains dismal with the mean survival period of 7 months.

Conclusion: Although extremely rare, MRTK might happen in adults. We report the first case of adult MRTK with positive family history of rhabdoid tumor of CNS, underscoring the importance of family history in reaching the diagnosis and highlighting the role of genetics in this rare disease.