Sellar Atypical Teratoid/Rhabdoid Tumor (AT/RT): A Clinicopathologically and Genetically Distinct Variant of AT/RT.
Atypical teratoid/rhabdoid tumors (AT/RTs) are rare aggressive tumors of the central nervous system that predominantly affect infants. Although adult AT/RT are rare, accumulated cases have revealed adult-specific AT/RT in the sellar region. Twelve previously reported cases of sellar AT/RT exclusively occurred in adult females, suggesting biological differences from conventional infant AT/RT. We herein investigated a series of 6 sellar AT/RT for histopathologic features, the molecular status of the INI1/SMARCB1 gene, and clinical courses. All 6 cases were adult females, ranging in age from 21 to 69 years old. Tumors were histologically characterized by a hemangiopericytoma-like stag-horn vasculature within a dense, diffuse proliferation of jumbled cells and a small number of scattered rhabdoid cells. This vascular pattern is not a common finding in AT/RT and appears to be a characteristic histology of sellar AT/RT. Biallelic alterations in the INI1 gene were identified by fluorescence in situ hybridization, direct sequencing, and multiple ligation-dependent probe amplification analyses in 4 of the 5 cases analyzed. Three of the 4 cases harbored 2 different mutations, presumably on different alleles (compound heterozygous mutations), and 1 case of which had a splice-site mutation. Combined with previous findings, the prevalence of compound heterozygous mutations and splice-site mutations was significantly higher in sellar AT/RT than in pediatric AT/RT. Sellar AT/RT represent a clinicopathologically and possibly genetically distinct variant of AT/RT showing a characteristic demography, different patterns of INI1 alterations, and a histology featured by a unique vasculature.
*Department of Human Pathology, Gunma University Graduate School of Medicine ††Department of Pathology, Gunma University Hospital, Maebashi †Department of Diagnostic Pathology, Hyogo Cancer Center, Akashi ‡Department of Pathology, Toranomon Hospital §Department of Neurosurgery, Japanese Red Cross Medical Center, Tokyo ∥Department of Pathology, Institute of Biomedical and Health Sciences, Hiroshima University ¶Department of Clinical Oncology and Neuro-oncology Program, Hiroshima University Hospital, Hiroshima #Department of Neurosurgery, Yamagata University School of Medicine, Yamagata **Department of Pathology, Kyoto University Hospital, Kyoto ‡‡Department of Pathology, Hidaka Hospital, Takasaki, Japan.
Satoshi
S
Nakata
Sumihito
S
Nobusawa
Takanori
T
Hirose
Shinji
S
Ito
Naoko
N
Inoshita
Shunsuke
S
Ichi
Vishwa J
VJ
Amatya
Yukio
Y
Takeshima
Kazuhiko
K
Sugiyama
Yukihiko
Y
Sonoda
Hironori
H
Haga
Junko
J
Hirato
Yoichi
Y
Nakazato
Hideaki
H
Yokoo
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D009154:Mutation; D010911:Pituitary Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology*; D018335:Rhabdoid Tumor / Q000235:genetics* / Q000401:mortality / Q000473:pathology*; D000071796:SMARCB1 Protein / Q000235:genetics*; D012658:Sella Turcica / Q000473:pathology*; D013724:Teratoma / Q000235:genetics* / Q000401:mortality / Q000473:pathology*
D014408:Biomarkers, Tumor; D000071796:SMARCB1 Protein; C513266:SMARCB1 protein, human