Atypical Teratoid/Rhabdoid Tumors in Adult Patients: CT and MR Imaging Features

Abstract

SUMMARY:Primary AT/RT is a rare highly malignant tumor of the CNS, usually occurring in children younger than 5 years of age. The objective of this study was to characterize the CT and MR imaging findings in a series of 5 adult patients with pathologically proved AT/RT. All 5 AT/RTs were supratentorial. In 2 patients who underwent nonenhanced CT, the tumors appeared isoattenuated, and 1 of the 2 tumors contained calcifications. Solid portions of the tumors on MR imaging were isointense on T1-weighted, T2-weighted, and FLAIR images, and 1 case showed restricted diffusion on DWI. The tumors also demonstrated a bandlike rim of strong enhancement surrounding a central cystic area on contrast-enhanced T1-weighted imaging. One tumor was associated with destruction of the calvaria. Although AT/RTs can have nonspecific findings, the tumors in our series were large and isointense on T1-weighted, T2-weighted, and FLAIR images with central necrosis and prominent rim enhancement.ABBREVIATIONS: ADC ϭ apparent diffusion coefficient; AT/RT ϭ atypical teratoid/rhabdoid tumor; CNS ϭ central nervous system; DWI ϭ diffusion-weighted imaging; FLAIR ϭ fluid-attenuated inversion recovery; L ϭ left; mRNA ϭ messenger ribonucleic acid; N/A ϭ not available, ND ϭ not depicted; OS ϭ overall survival; PNET ϭ primitive neuroectodermal tumor; PR ϭ partial resection; R ϭ right; TR ϭ total resection A lthough AT/RT was first described as a rare, highly malignant childhood neoplasm of the kidney, it has also been reported at several extrarenal sites including the skin, chest wall, liver, thymus, optic nerve, and the CNS. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] When found in the CNS, it usually arises from the posterior fossa and is most commonly found in children younger than 5 years of age.17 To our knowledge, only 29 cases of primary AT/RT of the CNS in adults have been reported (On-line Table). 18-30The On-line Table summarizes the clinical and imaging data from our patients and from those in the literature.The prognosis of patients with an AT/RT is poor, especially in patients younger than 3 years of age, with a survival time that averages 15 months in children and 38 months in adults. 10,18,19,24 To our knowledge, there are only limited case reports describing the imaging features of this entity in adults. 8,9,18,19,[21][22][23][24][25][26][27][28][29][30][31] The goal of this study was to characterize the CT and MR imaging features of CNS AT/RT in 5 adults. Materials and Methods PatientsThis study was approved by our institutional review board in accordance with standards of the National Institutes of Health. Five consecutive adult patients who received a diagnosis of AT/RT from January 2001 to October 2009 were included in the study. All patients had undergone surgical resection of their tumor and had received postoperative radiation therapy and chemotherapy. The resection specimens were collected and analyzed at 1 central pathology laboratory. Definitive diagnosis was based on histologic and immunohistochemical evaluation...

Atypical teratoid/rhabdoid tumor in sellar turcica in an adult: A case report and review of the literature

“…[3238] Adult cases are rare and, as far as we are aware, only 42 cases have been reported to date [Table 1]. [2345910111213141516171821232425262729303133343536373941] Furthermore, there are only seven adult cases arising in the sellar turcica described in the literature. [224253034]…”

A 47‐year old female with a destructive sellar mass

“…The neoplasm is rare, accounting for approximately 2% of childhood CNS tumors. Even more unusual is the adult‐onset variant, which typically involves the supratentorial region . Based on the location of the lesion seen in this case, the differential diagnosis includes pituitary adenoma, meningioma, lymphoma, germ cell tumor, chordoid glioma or a metastasis.…”

“…Imaging features, however, can be helpful in narrowing the list of possible diagnoses. On imaging, AT/RT in adults usually appears as a well‐demarcated mass with heterogeneous enhancement on T1‐weighted images , features that make a pituitary etiology less likely. Also described, but not seen in this case, is a band‐like wavy rim of enhancement surrounding a cystic or necrotic focus.…”

Bone Involvement in Atypical Teratoid/Rhabdoid Tumors of the CNS

“…[11][12][13]21 Rare reports of patients affected by AT/RT demonstrating involvement of the skull in children and adults exist. 11,19 Two children with AT/RT of clival location (similar to our patient 5) have been described, whose radiologic appearance also led to the suspicion of chordoma despite very low signal on T2-weighted images. 22,23 Indeed, in our patient, the possibility of "poorly differentiated chordoma" 24,25 was also discussed during neuropathologic evaluation but rejected in favor of AT/RT, because the tumor lacked any convincing chordoid differentiation.…”

“…7,18 Rarely, adults are diagnosed with AT/RT, which in this age group are mainly supratentorial, in contrast to young children, in whom infratentorial tumor location predominates. 18,19 In addition to the high cellularity of the tumor reflected by low signal on T2-weighted and ADC images, 20 bleeding residues, peripheral cysts, and a distinct pattern of contrast enhancement have been described as frequent findings. [11][12][13]21 Rare reports of patients affected by AT/RT demonstrating involvement of the skull in children and adults exist.…”