Extrarenal Rhabdoid Tumor



Extrarenal Rhabdoid Tumor


Cyril Fisher, MD, DSc, FRCPath









Hematoxylin & eosin shows sheets of rhabdoid cells without architecture. The cells have amphophilic cytoplasm and eccentric rounded nuclei with large nucleoli and are often discohesive, as seen here.






Hematoxylin & eosin shows cell detail, with abundant cytoplasm containing pale-staining inclusions image. These are composed of cytokeratin- and vimentin-intermediate filaments. Note the prominent nucleoli.


TERMINOLOGY


Abbreviations



  • Extrarenal rhabdoid tumor (ERT)


Synonyms



  • Malignant rhabdoid tumor


  • Atypical teratoid/rhabdoid tumor: Term for similar neoplasm in central nervous system


Definitions



  • Rare malignant neoplasm of characteristic polygonal cells



    • Large nuclei with prominent nucleoli


    • Abundant eosinophilic cytoplasm, which displaces nucleus to 1 side


  • Requires exclusion of specific tumor types with occasional rhabdoid cytomorphology



    • Extraskeletal myxoid chondrosarcoma


    • Leiomyosarcoma


    • Myoepithelial tumor


    • Gastrointestinal stromal tumor


    • Endometrial stromal sarcoma


    • Synovial sarcoma


    • Mesothelioma


    • Carcinoma


    • Melanoma


  • Can be pure or form part of specific tumor type (composite ERT)


ETIOLOGY/PATHOGENESIS


Genetic Factors



  • Some have abnormalities of chromosome 22q11.2


  • Some patients have germline mutations of hSNF5/SMARCB1 gene


  • Some associated with myofibroma- or hamartoma-like cutaneous lesions


  • Rarely multiple


CLINICAL ISSUES


Epidemiology



  • Incidence



    • Rare


  • Age



    • Majority in childhood, including congenitally


    • Rare examples in adults after all mimics excluded


Site



  • Deep soft tissue or skin



    • Axial and paraxial, cervical or paravertebral regions, vulva, perineum


    • Thigh, limb girdles


  • Viscera



    • GI tract, liver, heart, bladder, brain


Presentation



  • Rapidly growing mass, occasionally ulcerates


Natural History



  • Aggressive with frequent local recurrence and metastasis


Treatment



  • Surgical approaches



    • Excision where feasible


  • Drugs



    • Chemotherapy



      • Rarely effective


Prognosis



  • Very poor


MACROSCOPIC FEATURES


General Features



  • Multinodular, nonencapsulated, poorly circumscribed


  • Pale or tan, with hemorrhage and necrosis



Size



  • Up to 5 cm or more at presentation

Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Extrarenal Rhabdoid Tumor
Premium Wordpress Themes by UFO Themes
%d bloggers like this: