Metastatic SMARCB1-Deficient Renal Medullary Carcinoma without Hemoglobinopathy with Durable and Dramatic Response to Pembrolizumab plus Lenvatinib: Case Report

Case Rep Oncol. 2024 Sep 17;17(1):1025-1033. doi: 10.1159/000540937. eCollection 2024 Jan-Dec.

Abstract

Introduction: Renal medullary carcinoma (RMC) is a rare form of renal cell carcinoma (RCC) that is typically associated with a loss of function in SMARCB1 and diagnosis of sickle cell or other hemoglobinopathy. In rare cases, this disease can be seen in patients without hemoglobinopathy and is classified as "SMARCB1-deficient RMC without hemoglobinopathy" or referred to as "RCC unclassified with medullary phenotype" in some of the literature. Platinum-based cytotoxic chemotherapy is currently the recommended first-line treatment for this rare disease.

Case presentation: Here we report a 53-year-old male who was diagnosed with metastatic SMARCB1-deficient RMC without hemoglobinopathy after presenting with left flank and abdominal pain. After initiating first-line pembrolizumab and lenvatinib systemic therapy, imaging showed regression at 6 weeks. To date, this patient continues to show a near complete response to this treatment regimen.

Conclusion: To our knowledge, this is the first documented case of SMARCB1-deficient RMC without hemoglobinopathy to receive this treatment regimen and show such a response.

Keywords: Renal medullary carcinoma; SMARCB1-deficient renal medullary carcinoma.

Publication types

  • Case Reports

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