Malignant rhabdoid tumor

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Sujit Routray, M.D. [2]

Synonyms and keywords: Malignant rhabdoid tumor; Malignant rhabdoid neoplasm; Atypical teratoid rhabdoid tumor

Overview

• Malignant rhabdoid tumor is one of the aggressive tumors in the pediatric population. It was originally described as a rhabdomyosarcomatoid variant of Wilms' tumor, which is primarily a renal tumor.
• Malignant rhabdoid tumor was first described as a variant of Wilms' tumor of the kidney, in 1978.
• Malignant rhabdoid tumor is comprised of rhabdoid tumor cells and varying amounts of small undifferentiated primitive neuroectodermal tumor (PNET)-like, mesenchymally, and/or epithelially differentiated tumor cells.
• Gene involved in the pathogenesis of malignant rhabdoid tumor include SMARCB1 (hSNF5/INI-1), a tumor suppressor gene.
• Malignant rhabdoid tumor is characterized by loss of the long arm of chromosome 22, which results in loss of the hSNF5/INI-1 gene.
• INI1, a member of the SWI/SNF chromatin remodeling complex, is important in maintenance of the mitotic spindle and cell cycle control.
• Malignant rhabdoid tumor may be associated with rhabdoid predisposition syndrome.
• Common locations associated with malignant rhabdoid tumor include:

• Kidney: malignant rhabdoid tumor of the kidney (most common)
• Intracranial: atypical teratoid rhabdoid tumor
• Soft tissues: breast, skin, orbit, liver, etc

• Almost all reported cases of malignant rhabdoid tumor, regardless of site of origin, occur in young children between birth and 2 years of age.
• In approximately 10% of cases of renal malignant rhabdoid tumor, the patients subsequently develop intracranial atypical teratoid rhabdoid tumor.
• Symptoms of malignant rhabdoid tumor of kidney include:

• Hematuria
• Loin/flank mass