Rhabdoid tumor of the kidney is a highly invasive and highly lethal neoplasm of young children with genetic abnormalities of SMARCB1/INI1 tumor suppressor gene.
It comprises 2% of pediatric renal neoplasms.
Ninety percent of the cases occurs in patients before 3 years of age.
ts male-to-female ratio is 1.5:1.
There is no site predilection.
There is no standard treatment option for rhabdoid tumor of the kidney.
The patients frequently die within 1 year of diagnosis. Hematuria and abdominal mass are the most common presentations.
Tumors are typically large, hemorrhagic, and necrotic, with ill-defined borders (Weeks et al. 1989).
It is an infiltrative, necrotic hemorrhagic tumor composed of sheets of large discohesive polygonal cells with large vesicular nuclei showing prominent central nucleoli and hyaline pink cytoplasmic inclusions (Weeks et al. 1989).
Loss of INI1 protein by immunohistochemistry is a sensitive and specific marker of these neoplasms.
The molecular hallmark is the biallelic inactivation of the SMARCB1 tumor suppressor gene, which resides on the long arm of chromosome 22. Inactivation of this gene is also seen in morphologically similar rhabdoid tumors which occur in the soft tissue and brain (atypical teratoid/rhabdoid tumor) (Eaton et al. 2011).
The differential diagnosis includes renal medullary carcinoma (sickle cell trait, older age), cellular mesoblastic nephroma (spindle cell), and clear cell sarcoma of the kidney (lack the prominent nucleoli).