Renal medullary carcinoma: a systematic review of clinical and radiological findings

BACKGROUND AND AIMS: Renal medullary carcinoma (RMC) is a rare subtype of renal cell carcinoma, typically described in young patients with sickle cell trait, which follows an aggressive course. We aimed to perform a systematic review of all published cases of RMC from 1995 to 2024, to summarise the clinico-pathological and radiological features. METHODS: A systematic review of all published cases of RMC from 1995 to 2024 was performed. Patient demographics, clinical presentation, radiological features, metastatic profile, management, and overall survival were recorded. Sub-analysis was performed, grouped by sickle cell status. RESULTS: 219 cases from 103 articles were included, in addition to 5 previously unreported cases from our institution. 88% of patients had sickle cell haemoglobinopathy (SCH) (n = 168/192), with presentation at a younger age in patients with SCH (27.3 ± 13.7 versus 34.1 ± 19.1 years, p = 0.001). RMC was more frequently observed in the right kidney (64.6%, n = 122/189) than the left kidney (35.4%, n = 67/189) (p = < 0.001). Radiologically, the most common features were a central/endophytic location, hypo-enhancement relative to the adjacent cortex, and infiltrative margins. 20.7% (n = 42/203) were stage III at presentation and 70.9% (n = 144/203) of patients were Stage IV. Overall survival at 3 years was 74% for Stage I-II disease, 23% for Stage III disease, and 9% for Stage IV disease. CONCLUSIONS: Regardless of sickle cell status, RMC was shown to present at a relatively young age. It was classically seen as an infiltrative, poorly defined, endophytic tumour, centred on the renal medulla. RMC was found to be more commonly advanced at presentation and the overall survival in patients with nodal or distant metastases was poor.