Case Presentation: We present a case of new-onset heart failure in a 31-year-old African American woman in the context of metastatic RMC. The patient was presented with a shortness of breath, swelling and discomfort of left forearm. The patient’s clinical evaluation involved a chest CT scan, which showed a concerning 11.5 x 8.0 x 9.0 cm right renal mass on the upper pole of the right kidney and nodular and patchy densities in the lungs. Echo revealed a reduced left ventricular ejection fraction of 15-20%, elevated B-type Natriuretic Peptide. A right lung nodule biopsy did not confirm metastasis, prompting consideration of other potential diagnoses, including pheochromocytoma/paraganglioma. Patient’s metanephrines showed to be high. Further investigation of kidney biopsy identified SMARCB1 (INI1)-deficient renal cell carcinoma with positive OCT3/4 and negative ALK, favoring a medullary-like RCC.A subsequent biopsy of a painful left forearm mass confirmed metastatic SMARCB1/INI1-deficient renal cell carcinoma, ruling out pheochromocytoma. Experts in the field and tumor board were involved in this case, and CT scans and immunohistopathologies were discussed leading to the diagnosis of Renal Medullary Carcinoma. Repeat metanephrines and Chromogranin A were within normal limits. Patient hemoglobinopathy analysis was positive for sickle cell trait.
Discussion: This case highlights the complex and atypical presentation of RMC, a rare and aggressive renal malignancy often associated with sickle cell trait in young African American individuals. Three main mechanisms have been proposed to explain heart failure in patients with renal cell carcinoma: the development of an arteriovenous shunt, involvement of the renal vein, and subsequent IVC involvement, along with the secretion of angiogenic factors. RCCs are known to release high levels of pro-angiogenic factors, such as vascular endothelial growth factors (VEGFs), platelet-derived growth factors (PDGFs), and insulin-like growth factor (IGF-1), which may contribute to heart failure symptoms.The increased plasma metanephrines in our patient could be attributed to emotional stress after discovering the diagnosis, medical procedures, or the paraneoplastic effects of the tumor. The latter should be kept in mind since RCC can secrete or stimulate neuroendocrine hormones, and the renin-angiotensin-aldosterone system could also be affected.Unlike the typical triad of RCC—gross hematuria, flank pain, and a palpable abdominal mass—our patient did not present with these classic signs. Notably, there are few documented cases of RCC-related heart failure associated with IVC thrombosis. Given the young age, African American ethnicity, and sickle cell trait, this case underscores the importance of considering RMC in differential diagnoses for young patients presenting with new-onset heart failure.
Conclusions: We report this case to provide guidance to providers who may encounter renal cell malignancies with atypical presentation, specifically with heart failure. High-output heart failure due to renal medullary cancer in adults is uncommon, but its occurrence may not be insignificant.The significance of thorough diagnostic evaluation and multidisciplinary team involvement in rare malignancies showed to be important. Elevated CA-125 levels, as suggested by prior studies may be a useful marker for RMC diagnosis. Our case contributes valuable insights into the clinical presentation of RMC, given its unusual course.
