<unk>  and rhabdoid tumor share the term "rhabdoid" because under a microscope, both tumors resemble rhabdomyosarcoma.AT/RT Histology with numerous rhabdoid tumor cells Rhabdoid Tumor Cell - 400X Magnification Histology The tumor histopathology is jumbled small and large cells. The tissue of this tumor contains many different types of cells including the rhabdoid cells, large spindled cells, epithelial and mesenchymal cells, and areas resembling primitive neuroectodermal tumor (PNET). As much as 70% of the tumor may be made up of PNET-like cells. Ultrastructure characteristic whorls of intermediate filaments are seen in the rhabdoid tumors (as with rhabdoid tumors in any area of the body). Ho and associates found sickle-shaped embracing cells, previously unreported, in all of 11 cases of<unk> . Immunohistochemistry Immunohistochemistry for INI1, the product of the SMARCB1 gene<unk> ly defective in<unk> : Note the loss of brown staining in the nuclei of tumor cells with defective SMARCB1 as compared to retained staining of nuclei of vascular cells (internal positive control). Immunohistochemical staining is widely used in the diagnosis and treatment of cancer. Specific molecular markers are characteristic of particular cancer types. Immunohistochemistry is also widely used in basic research to understand the distribution and localization of biomarkers in different parts of a tissue. Proteins found in an<unk> /RT are: * Vimentin-positive * Cytokeratin-positive * Neuron specific enolase-positive * Epitelial membrane antigen-positive * Glial fibrillary acidic protein- positive * Synaptophysin * Chromogranin * Smooth muscle actin * Desmin * Carcinoembrionary antigen * CD99 antigen; * S-100 * neurofilaments * AFP – not found * HCG – negative Cytogenetic studies Cytogenetics is the study of a tumor’s genetic make-up. Fluorescent in situ hybridization may be able to help locate a mutation or abnormality that may be allowing tumor growth. This technique has been shown to be useful in identifying some tumors and distinguishing two histologically similar tumors from each other (such as<unk> s and PNETs). In particular, medulloblastmas/PNETs may possibly be differentiated cytogenetically from<unk> s, as chromosomal deletions of 17p are relatively common with medulloblastoma and abnormalities of 22q11.2 are not seen. However, chromosomal 22 deletions are very common in<unk> s. In importance of the hSNF5/INI1 gene located on chromosomal band 22q11.2 is highlighted, as the mutation’s presence is sufficient to change the diagnosis from a medulloblastoma or PNET to the more aggressive<unk>  classification. However, this mutation is not present in 100% of cases. Therefore, if the mutation is not present in an otherwise classic<unk>  immunohistochemical and morphologic pattern then the diagnosis remains an<unk> .
Atypical teratoid rhabdoid tumor
Malignant rhabdoid tumour
Pediatric ependymoma
Neurothekeoma
Endodermal sinus tumor
Sialoblastoma
Ameloblastoma
Primitive neuroectodermal tumor