Atypical teratoid/rhabdoid tumor in adult: case series and an integrated survival analysis

Malignant Rhabdoid Tumor and Related Pediatric Tumors: Multimodality Imaging Review with Pathologic Correlation

Malignant rhabdoid tumors (MRTs) are rare but lethal solid neoplasms that overwhelmingly affect infants and young children. While the central nervous system is the most common site of occurrence, tumors can develop at other sites, including the kidneys and soft tissues throughout the body. The anatomic site of involvement dictates tumor nomenclature and nosology. While the clinical and imaging manifestations of MRTs and other more common entities may overlap, there are some site-specific distinctive imaging characteristics. Irrespective of the site of occurrence, somatic and germline mutations in SMARCB1, and rarely in SMARCA4, underlie the entire spectrum of rhabdoid tumors. MRTs have a simple and remarkably stable genome but can demonstrate considerable molecular and biologic heterogeneity. Related neoplasms encompass an expanding category of phenotypically dissimilar (nonrhabdoid tumors driven by SMARC-related alterations) entities. US, CT, MRI, and fluorodeoxyglucose PET/CT or PET/MRI facilitate diagnosis, initial staging, and follow-up, thus informing therapeutic decision making. Multifocal synchronous or metachronous rhabdoid tumors occur predominantly in the context of underlying rhabdoid tumor predisposition syndromes (RTPSs). These autosomal dominant disorders are driven in most cases by pathogenic variants in SMARCB1 (RTPS type 1) and rarely by pathogenic variants in SMARCA4 (RTPS type 2). Genetic testing and counseling are imperative in RTPS. Guidelines for imaging surveillance in cases of RTPS are based on age at diagnosis. ©RSNA, 2024 Supplemental material is available for this article.

An adult with recurrent atypical teratoid rhabdoid tumor of the spine

Atypical teratoid rhabdoid tumors (AT/RT) are rare and highly malignant CNS neoplasms primarily affecting children. Adult cases are extremely uncommon, with only approximately 92 reported. Spinal AT/RT in adults is particularly rare. Here, we present the case of a 50-year-old patient diagnosed with AT/RT of the spine. Initially, they were diagnosed and treated for a spinal ependymoma. However, after 10 years, a recurrence was detected through magnetic resonance imaging (MRI) and the tumor was reclassified as AT/RT. We discuss the significance of SMARCB1 gene mutations in diagnosing AT/RT and describe our unique treatment approach involving surgery, radiation and anti-PD1 therapy in this patient.

Atypical Teratoid Rhabdoid Tumor: Proposal of a Diagnostic Pathway Based on Clinical Features and Neuroimaging Findings

PURPOSE

To assess the main imaging and clinical features in adult- and pediatric-onset atypical teratoid rhabdoid tumor (ATRT) in order to build a predefined pathway useful for the diagnosis.

METHODS

We enrolled 11 ATRT patients (10 children, one adult) and we conducted a literature search on PubMed Central using the key terms "adult" or "pediatric" and "atypical teratoid/rhabdoid tumor". We collected clinical and neuroradiological data reported in previous studies and combined them with those from our case series. A three step process was built to reach diagnosis by identifying the main distinctive clinical and imaging features.

RESULTS

Clinical evaluation: neurological symptoms were nonspecific. ATRT was more frequent in children under 3 years of age (7 out of 10 children) and infratentorial localization was reported more frequently in children under the age of 24 months. Midline/off-midline localization was influenced by the age.

IMAGING FINDINGS

Preferential location near the ventricles and liquor spaces and the presence of eccentric cysts were hallmark for ATRT; higher frequency of peripheral cysts was detected in children and in the supratentorial compartment (five out of eight patients with solid-cystic ATRT). Leptomeningeal dissemination at diagnosis was common (5 out of 10 children), while intratumoral hemorrhage, calcifications, and high cellularity were non-specific findings. Histopathological analysis: specific immunohistochemical markers were essential to confirm the diagnosis.

CONCLUSION

In younger children, a bulky, heterogeneous mass with eccentric cystic components and development near ventricles or cisternal spaces may be suggestive of ATRT. ATRT diagnosis is more challenging in adults and relies exclusively on neuropathological examination.

Atypical Teratoid Rhabdoid Tumor: A Possible Oriented Female Pathology?

Atypical teratoid rhabdoid tumor is a rare lesion that occurs mainly in children can be supratentorial or infratentorial and it accounts for 1-2% of pediatric brain tumors and over 10% of central nervous system (CNS) tumors in infants, with a male preponderance up to 3 years of age, more than 50% of these occur in the cerebellum. In this report we describe four new cases of sellar AT/RTs underwent endoscopic endonasal approach and different adjuvant therapies. Our aim is to report the clinical, radiological and pathological features of these rare lesions, focusing on the possibility to perform an early diagnosis and appropriate therapeutic strategy.

Atypical teratoid/rhabdoid tumor in adults: a systematic review of the literature with meta-analysis and additional reports of 4 cases

INTRODUCTION

Atypical teratoid/rhabdoid tumor (AT/RT) is a highly aggressive embryonal CNS neoplasm, characterized by inactivation of SMARCB1 (INI1) or rarely of SMARCA4 (BRG1). While it is predominantly a childhood tumor, AT/RT is rare in adults.

METHODS

We provide a comprehensive systematic review of literature with meta-analysis; 92 adult cases were found from 74 articles. We additionally present 4 cases of adult AT/RTs (age ranging from 19 to 29 years), located to cerebellum in 2 cases, to ponto-cerebellar angle in 1 case and to spinal cord in the remaining case.

RESULTS

Microscopic features of our 4 cases showed a highly cellular tumor with rhabdoid morphology and high mitotic activity. All tumor cells lacked nuclear SMARCB1/INI1 protein expression. In case no. 3 we also performed methylation profiling which clustered the tumor with pediatric AT/RT-MYC subgroup. Prognosis remains poor in both pediatric and adult population with a median overall survival of 11 months. Our review demonstrated median overall survival of 15 months among the adult populations. However, consistent with a recent review, adult AT/RT seems to have highly variable prognosis and some patients reach long term survival with 22.9% of 5-year survival without evidence of disease and mean follow up time of 35.9 months (SD = 36.5). 27.1% of dissemination was also reported among the adult population.

CONCLUSIONS

Adult AT/RTs predominantly arise in female patients and in supratentorial location. Midline structures, including the sellar region, are the most affected sites, especially among females aged > 40 years. Male gender is more prevalent between the age of 18 and 40 years and more frequently associated with non-midline tumors. Factors significantly associated with better prognosis are patient's age (< 40 years), combined radio-chemotherapy adjuvant approach and Ki-67 score < 40%.

Primary diffuse leptomeningeal atypical teratoid rhabdoid tumor (AT/RT) demonstrating atypical imaging findings in an adolescent patient

Atypical teratoid rhabdoid tumor (AT/RT) is a highly malignant central nervous system embryonal tumor, which typically affects the posterior fossa of young children. Primary diffuse leptomeningeal AT/RT, affecting the leptomeninges without any intraparenchymal mass in the brain and spinal cord, is an extremely rare form of AT/RT. Only 5 such cases have been reported previously, none of which underwent Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography (FDG-PET). We herein report a case of primary leptomeningeal AT/RT in an adolescent patient who underwent computed tomography, magnetic resonance imaging and FDG-PET. The computed tomography and magnetic resonance imaging indicated diffusely thickened leptomeninges without any intraparenchymal masses in the head and spine. Furthermore, there were multiple nodules on the thickened leptomeninges. On FDG-PET, the thickened leptomeninges and nodules demonstrated a lower standardized uptake value than that of the normal cerebral cortex. Biopsy and histopathological studies confirmed the diagnosis of AT/RT. Despite its rare occurrence, it is important to recognize primary diffuse leptomeningeal AT/RT for correct diagnosis and management of patients.