Malignant rhabdoid tumour pathophysiology

Genetics
It should be noted that there have been reported cases of a child having both atypical teratoid rhaboid tumors in the brain as well as rhabdoid tumors of the kidney. Weeks and associates reported on 111 renal rhabdoid cases of which 13.5% also had a central nervous system malignancy. It has been hypothesized that a germline INI mutation may predispose a child to these tumors. There have been some references in the literature alluding to a new diagnosis called rhabdoid predispostion syndrome related to the gene hSNF5/INI1.

Pathophysiology
Malignant rhabdoid tumors (MRT) are a rare and highly malignant childhood neoplasm. Later rhabdoid tumors outside the kidney were reported in many tissues including the liver, soft tissue, and the central nervous system. Several cases of primary intracranial MRT have been reported since its recognition as a separate entity in 1978. The term "rhabdoid" was used due to its similarity with rhabdomyosarcoma under the light microscope. The exact pathogenesis of MRT is unknown.

The cerebellum is the most common location for primary intracerebral MRT (i.e., AT/RT). Biggs et al were first to report a primary intracranial MRT around 1987.

Although the cell of origin is not know, cytogenetic studies have suggested a common genetic basis for rhabdoid tumors regardless of location with abnormalities in chromosome 22 commonly occurring.

Rhabdoid tumors in kidney and brain
Considerable debate has been focused on whether AT/RTs are the same as rhabdoid tumors of the kidney (i.e., just extra-renal MRTs (Maligant Rhaboid Tumors). The recent recognition that both CNS atypical teratoid/rhabdoid tumors (AT/RTs) and MRTs have deletions of the INI1 gene in chromosome 22 indicates that rhabdoid tumors of the kidney and brain are identical or closely related entities.  Although, the CNS variant tends to have its mutations on Taxon 9 and MRTs elsewhere.  This observation is not surprising because rhabdoid tumors at both locations possess similar histologic, clinical, and demographic features. Moreover, 10-15% of patients with MRTs have synchronous or metachronous brain tumors, many of which are second primary malignant rhabdoid tumors.   This similarity excludes composite Rhabdoid tumors, which occur mainly in adults.