Renal Medullary Carcinoma
A highly aggressive carcinoma centered on the renal medulla associated with sickle cell and related hemoglobinopathies (Davis et al. 1995).
Renal medullary carcinoma is a very uncommon tumor.
There is a predilection for young adults.
There is a remarkable male predominance.
By definition, it is centered on the renal medulla.
Radical nephrectomy is the standard treatment.
Renal medullary carcinoma is an aggressive tumor. All patients are symptomatic at diagnosis with flank or abdominal pain and gross hematuria, with metastatic disease at the time of diagnosis.
These tumors are poorly circumscribed medulla-centered and variable in size.
Tumors are consistently positive for PAX8 and CK7. Loss of INI1 (Fig. 1b) and acquisition of expression of OCT3/OCT4 are diagnostically helpful.
Molecular studies have shown loss of heterozygosity or hemizygous deletions at the SMARCB1 (INI1) locus and the involvement of genes related to hypoxia-induced signaling pathways.
There are overlapping features with collecting duct carcinoma (which is characterized by absence of hemoglobinopathy and normal expression of INI1) and with urothelial carcinoma of the renal pelvis (which is associated with the presence of urothelial carcinoma in situ) (Amin et al. 2014; Sirohi et al. 2017; Ohe et al. 2018).