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Cytomorphological features of atypical teratoid/rhabdoid tumor: An account of 12 years' experience
Author(s) -
Güner Güneş,
Önder Sevgen,
Söylemezoğlu Figen
Publication year - 2014
Publication title -
diagnostic cytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.417
H-Index - 65
eISSN - 1097-0339
pISSN - 8755-1039
DOI - 10.1002/dc.23140
Subject(s) - medulloblastoma , pathology , ependymoma , germinoma , medicine , atypical teratoid rhabdoid tumor , primitive neuroectodermal tumor , differential diagnosis , cd99 , immunohistochemistry , vimentin , radiology , radiation therapy
Atypical teratoid rhabdoid tumor (AT/RT), an aggressive neoplasm mostly affecting young children, is characterized by rhabdoid cells together with epithelial, mesenchymal and primitive differentiation. Diagnosing AT/RT in intraoperative consultation and cerebrospinal fluid (CSF) samples may therefore pose problems. Fourteen immunohistochemically proven AT/RTs diagnosed between 2000 and 2012 were collected. Material consisted of squash smears prepared during intraoperative consultation (thirteen) and CSF smears (three). MGG‐stained CSF smears and H&E stained squash smears were reviewed by a neuropathologist and a cytopathologist. The intraoperative diagnoses were based on squash preparations and 3 out of 13 were consistent with AT/RT, 4 were considered medulloblastoma/primitive neuroectodermal tumors (PNET), 3 were deferred to paraffin section for tumor typing, and another 3 were misdiagnosed as ependymoma, germinoma and malignant glioma. Morphological assessment of intraoperative squash preparations showed that AT/RTs can have a mixture of pseudopapillary and diffuse smearing patterns. Cytomorphologic features consisted of characteristic rhabdoid cells (8/9); primitive appearing cells with a high nuclear to cytoplasmic ratio (7/9); bi‐/multinucleated cells (3/9); rare necrosis/apoptosis and mitoses. Three CSF smears showed high cellularity and inclusion‐bearing large cells. These cells are characterized by reniform/oval, eccentrically placed nuclei with cytoplasmic perinuclear light stained areas which are not seen in intraoperative squash preparations. Differential diagnosis of AT/RT in cytology involves medulloblastoma/PNET, ependymoma, glioma and germinoma among all others. Overlapping features of AT/RT with entities in differential diagnosis are discussed with a special emphasis of rhabdoid cells being the strongest feature to aid in reaching the diagnosis of AT/RT. Diagn. Cytopathol. 2014;42:856–862. © 2014 Wiley Periodicals, Inc.