renal medullary carcinoma
Renal medullary carcinoma is a rare and highly aggressive variant of renal cell cancer centered in the renal medulla.
Renal medullary carcinoma occurs almost exclusively in adolescent and young adult blacks with sickle cell trait or hemoglobin SC disease but not with homozygous hemoglobin SS sickle cell disease. Typically it affects patients around the age of 20 years with a range of 10-39 years .
Presenting symptoms include gross hematuria, abdominal or flank pain, and, less commonly, weight loss, palpable mass, or fever.
Renal medullary carcinoma is of epithelial origin and is thought to arise at the renal pelvic-mucosal interface .
The tumor quickly grows to fill the renal pelvis and invade vascular and lymphatic structures. Intraparenchymal satellite nodules are frequently present.
Imaging demonstrates a centrally located infiltrative lesion invading the renal sinus with peripheral caliectasis, reniform enlargement, and smaller peripheral satellite nodules.
There is heterogeneous enhancement at CT, and US shows heterogeneous echotexture.
The differential diagnosis of renal medullary carcinoma includes:
- transitional cell carcinoma: very rare in this age group
- rhabdoid tumor