Atypical teratoid rhabdoid tumor (AT/RT) in adults: review of four cases

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

BACKGROUND

Atypical teratoid/rhabdoid tumor (AT/RT) is well documented in children but less so in adults because of its rarity.

METHOD

We report a series of five cases, a literature review and quantitative analysis of the survival outcome of adult AT/RT patients.

RESULTS

Seventy-four patients including our five cases (male: female = 16: 58) were evaluated, whose median age was 32.5 years (18-80 years). The commonest location was the sellar region. Median overall survival (OS) was 12.5 months (0.5-204.00 months). Chemotherapy was associated with OS (HR: 0.349, 95%CI: 0.176-0.694, p = 0.003), while other factors did not influence OS. From Kaplan-Meier analysis, surgery combining postoperative chemotherapy and radiotherapy was associated with better prognosis (Log Rank: χ2 = 14.662, p = 0.001).

CONCLUSIONS

Adult AT/RT is commoner in females and tends to recur rapidly after surgical resection. Chemotherapy may provide a survival benefit. Surgery combined with postoperative chemotherapy and radiotherapy was associated with better prognosis for adult AT/RT patients, though the overall prognosis was still poor.

Two Cases of Atypical Teratoid/Rhabdoid Tumor in the Spinal Cord: Loss of SMARCB1 in a Child and Loss of SMARCA4 in an Adult

We compare two cases of primary spinal atypical teratoid/rhabdoid tumor (AT/RT), which rarely occurs in adults marked by SMARCA4 inactivation, and SMARCB1 inactivation for pediatric cases. AT/RT represents a highly malignant neoplasm comprising poorly differentiated constituents and rhabdoid cells, with SMARCB1(INI1) or infrequently SMARCA4 (BRG1) inactivation. These tumors are predominantly found in children but are rare in adults. While AT/RT can arise anywhere in the central nervous system, spinal cord localization is comparatively scarce. Despite mutation or loss of SMARCB1 at the 22q11.2 locus serving as the genetic hallmark of AT/RTs, infrequent cases of SMARCA4 inactivation with intact SMARCB1 protein expression are significant. We present each case of primary spinal tumors in a child and an adult, showing loss of the SMARCB1 and SMARCA4 proteins, respectively. Both tumors met the AT/RT diagnostic criteria. The histopathology demonstrated the presence of rhabdoid cells in both cases. Diagnosing primary spinal AT/RT with SMARCB1 protein loss remains a challenge. Nevertheless, the presence of SMARCB1 positivity alone must be noted to be insufficient to exclude the possibility of AT/RT diagnosis. In cases in which the diagnosis of AT/RT is highly suspected clinically, additional testing is warranted, including SMARCA4 analysis.

Atypical Teratoid/Rhabdoid Tumor of the Nervous System in Adults: Location-Related Features and Outcome

BACKGROUND

Atypical teratoid/rhabdoid tumor (AT/RT) of the nervous system is a rare and highly malignant neoplasm, mainly affecting children, first recognized as a pathologic entity in 1996 and added to the World Health Organization Classification of the Tumors of the Central Nervous System in 2000. AT/RT is even rarer among adults and is associated with a worse prognosis. The aim of the present study was to analyze the different tumor features according to the location in adults.

METHODS

A comprehensive and detailed literature review of AT/RTs in adults was made. The demographic, management, and outcome data associated with tumor location were analyzed and compared; histopathologic and molecular features were also discussed. Furthermore, we added our personal case with brain hemispheric localization and reported a progression-free survival of 103 months after gross total resection and adjuvant radiotherapy showing a peculiar histopathologic pattern.

RESULTS

Female sex is mainly affected by AT/RT on median localizations, both intracranial and spinal, and by all sellar region cases. Gross total resection is mainly achieved among lateral compared with median localizations. Combined radiotherapy and chemotherapy is the most adopted adjuvant treatment in all tumor localizations and is related to better outcome. Postoperative death is reported only among sellar region localizations, whereas brain hemispheric cases show the best overall survival.

CONCLUSIONS

AT/RTs show different and peculiar features according to their location, which significantly affects the outcome; precise knowledge of them helps the neurosurgeon in planning the best strategy for treatment.

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 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%.

Maternal embryonal leucine zipper kinase immunoreactivity in atypical teratoid/rhabdoid tumors: a study of 50 cases

Atypical teratoid/rhabdoid tumors (AT/RTs) are aggressive embryonal neoplasms of the central nervous system that correspond to WHO grade IV and have a dismal prognosis. The latest Central Brain Tumor Registry of the United States data shows that AT/RT constitutes 16.6% of all embryonal tumors in children. The molecular hallmark of this tumor is pathogenic SMARCB1 genetic alterations resulting in the loss of INI-1 immunopositivity, with fewer tumors harboring SMARCA4 (BRG1) variants. Maternal embryonal leucine zipper kinase (MELK) is a member of the Snf1/AMPK family of serine/threonine-protein kinases involved in various processes such as cell cycle regulation, self-renewal of stem cells, apoptosis, and splicing regulation. Recent studies have highlighted the involvement of MELK in AT/RT and its possible therapeutic role. The purpose of this study was to review the histological and immunohistochemical profile of AT/RT with special reference to MELK  staining. In this retrospective study conducted over 6 years, all diagnosed cases of AT/RT, defined by loss of INI-1 immunopositivity, were retrieved and studied. Demographic details of patients and microscopic findings were analyzed, with special attention to histological patterns and immunohistochemistry profile including MELK immunoreactivity. There were 50 cases of AT/RT diagnosed in the specified period. Of the cases operated at our institute during this period, embryonal tumors constituted 20.6% of all pediatric brain tumors with AT/RT representing 12.6% of this subset. The median age at presentation was 3.5 years (range: 8 months-22 years) and there were three adult cases. Males outnumbered females by a ratio of 1.94:1. Tumor location was distributed equally between the supratentorial and infratentorial compartments. Characteristic rhabdoid cells were identified in 70% of cases. Areas with epithelial, mesenchymal, and undifferentiated tumor cells were seen in 8%, 20%, and 52% of cases, respectively. Cells with vacuolated cytoplasm were noted in 28% of cases. Immunohistochemistry (IHC) showed a polyimmunophenotypic profile with immunopositivity for GFAP in 70%, Vimentin in 100%, SMA in 68%, and EMA in 88% of cases, indicating the remarkable heterogeneity of the tumor cells. MELK immunopositivity was noted in 83.33% of cases. Thus, atypical teratoid/rhabdoid tumors are rare neoplasms. In line with other studies, we show that these tumors occur predominantly in very young children and display marked variability on histology and IHC with loss of INI-1. MELK is presumed to be an important molecule involved in cell cycle regulation, proliferation, and other critical functions. High expression of MELK in AT/RT may suggest its plausible role in neoplastic transformation of embryonic and postnatal multipotent neural progenitors which in turn could explain the diverse morphological and immunohistochemical characteristics observed in these tumors.

A case of desmoplastic myxoid tumor, SMARCB1 mutant, in the pineal region

Desmoplastic myxoid tumor (DMT), SMARCB1 mutant is a recently proposed new entity that mainly occurs in the pineal region and has epigenetic features similar to those of atypical teratoid/rhabdoid tumors (AT/RT)-MYC and poorly differentiated chordomas. Herein, we present a new case of a 33-year-old man with headaches, dizziness, nausea, vomiting, and blurred vision, who was initially found to have a suspicious germinoma on imaging. After surgical removal of the lesion, the postoperative pathological diagnosis was DMT, SMARCB1 mutant. To the best of our knowledge, this is the first case reported in China. Our findings also extend the range of the immunohistochemical phenotype of this rare tumor.

Atypical Teratoid/Rhabdoid Tumor of the Cerebellum in an Adult: Case Report and Literature Review

BACKGROUND

Atypical teratoid/rhabdoid tumor (AT/RT) is a rare tumor that is most frequently encountered in the pediatric patient population. AT/RT accounts for approximately 1%-2% of all pediatric central nervous system tumors and roughly 10%-20% of tumors in patients younger than 3 years of age. While AT/RT has been encountered in the adult population, the vast majority of the cases reported occur in the supratentorial space. In the existing literature, only 3 adult cases that arise from the cerebellum have ever been reported.

CASE DESCRIPTION

A 38-year-old female presented with 6 months of worsening nausea, emesis, vertigo, diplopia, and coordination difficulty. Magnetic resonance imaging revealed a T1 avidly contrast-enhancing mass, composed of both cystic and solid areas, extending from the cerebellum into the fourth ventricle. Following a gross total resection, surgical pathology was consistent with AT/RT, with tumor cell loss of integrase interactor-1 (INI-1) observed via immunohistochemical staining.

CONCLUSIONS

This case represents just the fourth ever reported case of AT/RT arising from the cerebellum in an adult and the oldest reported age to date of a cerebellar AT/RT occurring in a female. Due to the paucity of reported adult AT/RT cases, little is known about adults with AT/RT. Further reports will function to improve the general understanding of AT/RT in the adult population.

Fulminant presentation of a SMARCB1-deficient, anterior cranial fossa tumor in adult

Background:

Malignant atypical teratoid rhabdoid tumor (ATRT) usually develops in children. ATRTs are rare in adults, with only one case in the literature describing involvement of the anterior skull base. These primary intracranial tumors are characterized molecularly as SMARCB1 (INI1) deficient. Different types of such SMARCB1-deficient tumors exist in adulthood, usually in the form of extracranial tumors. Very few cases of such a new entity, named SMARCB1-deficient sinonasal carcinoma have been described with intracranial penetration and involvement of the anterior cranial fossa.

Case Description:

A 36-year-old male presented with acute cognitive deterioration. Over few hours, he developed a fulminant herniation syndrome. Imaging showed a tumor in the anterior cranial fossa surrounded by massive brain edema. The tumor has destroyed the frontal bone with involvement of the nasal cavities and paranasal sinuses. The patient underwent emergent decompressive craniectomy and tumor debulking but could not be saved. Pathological analysis revealed a highly cellular tumor without rhabdoid cells but with areas of necrosis. Further immunohistochemical stains revealed that neoplastic cells were diffusely and strongly positive for epithelial membrane antigen and P63 and negative for SMARCB1 (i.e., loss of expression), confirming the diagnosis of sinonasal carcinoma.

Conclusion:

To the best of our knowledge, this is the first report of a fulminant presentation of a SMARCB1- deficient tumor in young adult, involving the anterior cranial fossa and the paranasal sinuses. The main differential diagnosis of aggressive, primary, intracranial SMARCB1-deficient tumors in adults includes ATRT, SMARCB1- deficient sinonasal carcinoma, rhabdoid meningioma, and rhabdoid glioblastoma. Atypical tumors involving the anterior skull base without a clear histopathological pattern should therefore be checked for SMARCB1 expression.

Adult Pineal Region Atypical Teratoid Rhabdoid Tumor: A Case for Aggressive Surgical and Chemoradiation Management with Comprehensive Literature Review

BACKGROUND

Atypical teratoid rhabdoid tumor (ATRT) is a rare, highly malignant central nervous system neoplasm classified as an embryonal grade IV neoplasm by the World Health Organization. ATRT generally occurs in children younger than 3 years, with 85 pathologically confirmed cases reported in adults. It is most commonly supratentorial, with only 9 confirmed adult cases localized to the pineal region.

CASE DESCRIPTION

The case is described of a 29-year-old man with a history of chronic migraines and a previously negative computed tomography scan of the head presenting with worsening headaches and new-onset diplopia with upward gaze palsy. Computed tomography and magnetic resonance imaging showed a hemorrhagic pineal mass with extension into the right thalamus. After resection, the immunohistochemical staining and cytogenetic profile proved consistent with ATRT, making it the ninth reported case of pineal ATRT in an adult, which was treated aggressively with good outcome.

CONCLUSIONS

Adult ATRT is rare, especially in the pineal region, with only 9 cases reported. Because of the aggressiveness, ATRT must be considered in the differential diagnosis of pineal region lesions because early diagnosis and aggressive treatment are key to prolonged survival.

Dural-based atypical teratoid/rhabdoid tumor in an adult: DNA methylation profiling as a tool for the diagnosis

Atypical teratoid/rhabdoid tumor (ATRT) is a malignant CNS embryonal tumor that mostly occurs in childhood, adult cases are rare. We report a case of a 23-year-old male with an extra-axial dura-based lesion in the left frontal area, previously diagnosed as gliosarcoma. After 6 years, the patient had a recurrence and the previous slides were reviewed. Tumor was positive for vimentin and negative for INI1. The differential diagnosis for this extra-axial tumor with long survival was rhabdoid meningioma with INI1 loss or ATRT. DNA methylation profiling was performed to reach the final and the most definitive diagnosis; the result was ATRT. Our case suggests the usefulness of DNA methylation profiling for diagnosing challenging CNS tumors.

Embryonal Tumors of the Central Nervous System: An Update

Embryonal tumors of the central nervous system (CNS) are rare, high-grade neoplasms predominantly affecting the pediatric population. Well-defined embryonal tumors include medulloblastoma, atypical teratoid/rhabdoid tumor, embryonal tumor with multilayered rosettes, C19MC-altered and embryonal tumor with multilayered rosettes, not otherwise specified, pineoblastoma, pituitary blastoma, CNS neuroblastoma, and ganglioneuroblastoma. Although their prognosis is nearly uniformly poor, the rapidly evolving understanding of their molecular biology contributes to diagnosis, prognosis, treatment, and clinical trial participation. Knowledge of current tumor stratification and diagnostic techniques will help pathologists guide care and preserve tissue for necessary or desired additional testing.

Biomarkers in tumors of the central nervous system - a review

Until recently, diagnostics of brain tumors were almost solely based on morphology and immunohistochemical stainings for relatively unspecific lineage markers. Although certain molecular markers have been known for longer than a decade (combined loss of chromosome 1p and 19q in oligodendrogliomas), molecular biomarkers were not included in the WHO scheme until 2016. Now, the classification of diffuse gliomas rests on an integration of morphology and molecular results. Also, for many other central nervous system tumor entities, specific diagnostic, prognostic and predictive biomarkers have been detected and continue to emerge. Previously, we considered brain tumors with similar histology to represent a single disease entity. We now realize that histologically identical tumors might show alterations in different molecular pathways, and often represent separate diseases with different natural history and response to treatment. Hence, knowledge about specific biomarkers is of great importance for individualized treatment and follow-up. In this paper we review the biomarkers that we currently use in the diagnostic work-up of brain tumors.

A Systematic Review of Atypical Teratoid Rhabdoid Tumor in Adults

Background: Atypical teratoid/rhabdoid tumor in adults is a relatively rare malignant neoplasm. It is characterized by the presence of rhabdoid cells in combination with loss of either the INI1 or BRG1protein from the tumor cells.

Methods: A systematic review was conducted using MEDLINE using the terms “atypical teratoid rhabdoid tumor” AND “adult.” The systematic review was supplemented with relevant articles from the references. Cases were included if the pathology was confirmed by loss of INI1 or BRG1. We included a case from our institution. The dataset was analyzed using descriptive statistics and log-rank test.

Results: A total of 50 cases from 29 articles were included in this study. The average age at diagnosis was 36.7 years. The most common locations reported are the sellar region and cerebral hemispheres (without deep gray matter involvement). Of the 50 cases, 14 were reported to show evidence of dissemination. The average overall survival was 20 months. There was a significant difference in survival between the adjuvant therapy groups (p = < 0.0001).

Conclusion: Atypical teratoid rhabdoid tumor of the central nervous system in adults is a rare neoplasm associated with a poor prognosis in a majority of patients. The treatment and clinical course are highly variable, and it remains unclear which factors impact prognosis.

Primary intracerebral INI1-deficient rhabdoid tumor with CD34 immunopositivity in a young adult

Background:

Primary CNS malignant rhabdoid tumors are very rare in adults and much less is known about their biological behavior than in children. Recently, two adult cases of SMARCB1 (also known as INI1)-deficient tumor with rhabdoid cells have been described, suggesting an emerging group of primary meningeal SMARCB1-deficient tumors. We have recently encountered a case of INI1-deficient tumor with similar histology and immunophenotype to the above cases, but with a superficial cerebral, yet apparent intra-axial origin.

Case Description:

A 22-year-old woman presented with approximately one year history of focal sensorimotor right upper limb seizures and recently developed a slowly progressive weakness in her right hand. An MRI of the brain demonstrated an avidly enhancing lesion centered on the left perirolandic region with no definite dural involvement. The patient underwent a complete surgical excision. Histology revealed a tumor with monotonous epithelioid and spindle-shaped cells in a mucoid/myxoid background. There was focal mitotic activity and a few necrotic areas, in addition to many rhabdoid cells. The immunohistochemistry was negative for INI1 and there was strong positivity with CD34, while focal smooth muscle actin (SMA) and epithelial membrane antigen (EMA) immunoreactivity were also noted.

Conclusions:

As an addition to the two cases of adult SMARCB1-deficient tumors recently described, we present a further adult case with a similar immunohistochemical profile but with an apparent intra-axial origin, questioning the necessary meningeal origin of this type of tumor. The prognosis of this adult INI1/SMARCB1-deficient tumor is to be determined, but may be better than the pediatric atypical/teratoid tumor (AT/RT).

Atypical Teratoid Rhabdoid Tumor: Two Case Reports and an Analysis of Adult Cases with Implications for Pathophysiology and Treatment

We present the first quantitative analysis of atypical teratoid rhabdoid tumors (ATRT) in adults, including two patients from our own institutions. These are of interest as one occurred during pregnancy and one is a long-term survivor. Our review of pathological findings of 50 reported cases of adult ATRT leads us to propose a solely ectodermal origin for the tumor and that epithelial–mesenchymal transition (EMT) is a defining feature. Thus, the term ATRT may be misleading. Our review of clinical findings shows that ATRT tends to originate in mid-line structures adjacent to the CSF, leading to a high rate of leptomeningeal dissemination. Thus, we hypothesize that residual undifferentiated ectoderm in the circumventricular organs, particularly the pituitary and pineal glands, is the most common origin for these tumors. We note that if growth is not arrested soon after diagnosis, or after the first relapse/progression, death is almost universal. While typically rapidly fatal (as in our first case), long-term remission is possible (as in our second). Significant predictors of prognosis were the extent of resection and the use of chemotherapy. Glial differentiation (GFAP staining) was strongly associated with leptomeningeal metastases (chi-squared p = 0.02) and both predicted markedly worse outcomes. Clinical trials including adults are rare. ATRT is primarily a disease of infancy and radiotherapy is generally avoided in those aged less than 3 years old. Treatment options in adults differ from infants in that cranio-spinal irradiation is a viable adjunct to systemic chemotherapy in the adult population. Given the grave prognosis, this combined approach appears reasonable. As effective chemotherapy is likely to cause myelosuppression, we recommend that stem-cell rescue be available locally.

Does Stereotactic Radiosurgery Positively Impact the Local Control of Atypical Teratoid Rhabdoid Tumors?

BACKGROUND

Atypical teratoid rhabdoid tumors (ATRTs) are rare and aggressive tumors, usually affecting patients younger than 3 years of age, that are characterized by a poor prognosis. Nowadays multimodal management, including surgery, chemotherapy and radiation therapy (RT), is advocated depending on the patients' age and tumor stage, even if no consensus exists regarding the best treatment modality. Local RT seems to be the most effective treatment in prolonging progression-free and overall survival rates, although RT might not be used on younger children because of the risk of neurocognitive and endocrine sequelae. Stereotactic radiosurgery (SRS) is a valuable alternative therapeutic option to conventional RT because of the more conformal dose delivery. The aim of this study was to review the available literature on SRS in the management of ATRT.

METHODS

The authors carried out a systematic review of PubMed, Web of Science, and Google Scholar for clinical reports dealing with SRS for the management of ATRT.

RESULTS

Nine studies describing 12 patients treated with SRS for ATRT were included in the analysis. Patient's clinical features, radiosurgical treatment characteristics, and follow-up data of the pertinent literature were reviewed critically. SRS represents a feasible and effective therapeutic option in the management of ATRT. Local control has been reported in 66.7% of cases; however, 33.3% of patients experienced poor survival because of craniospinal tumor dissemination.

CONCLUSION

SRS should be considered in the multimodal treatment of ATRT, and future studies should focus on a better definition of the role played by SRS in their management.

Glioma Subclassifications and Their Clinical Significance

The impact of targeted therapies in glioma has been modest. All the therapies that have demonstrated a significant survival benefit for gliomas in Phase III trials, including radiation, chemotherapy (temozolomide and PCV [procarbazine, lomustine, vincristine]), and tumor-treating fields, are based on nonspecific targeting of proliferating cells. Recent advances in the molecular understanding of gliomas suggest some potential reasons for the failure of more targeted therapies in gliomas. Specifically, the histologic-based glioma classification is composed of multiple different molecular subtypes with distinct biology, natural history, and prognosis. As a result of these insights, the diagnosis and classification of gliomas have recently been updated by the World Health Organization. However, these changes and other novel observations regarding glioma biomarkers and subtypes highlight several clinical challenges. First, the field is faced with the difficulty of reinterpreting the results of prior studies and retrospective data using the new classifications to clarify prognostic assessments and treatment recommendations for patients. Second, the new classifications and insights require rethinking the design and stratification of future clinical trials. Last, these observations provide the essential framework for the development and testing of new specific targeted therapies for particular glioma subtypes. This review aims to summarize the current literature regarding glioma subclassifications and their clinical relevance in this evolving field.

Atypical Teratoid/ Rhabdoid Tumor of Brain: a Clinicopathologic Study of Eleven Patients and Review of Literature

Background:

Atypical teratoid/ rhabdoid tumor (AT/RT) is a rare aggressive embryonal central nervous system (CNS) tumor of infancy and early childhood. Majority of the cases arise in the posterior fossa, and remaining in the cerebrum.

Aims:

To analyze the clinicopathologic features of AT/RT on a cohort of cases.

Materials and methods:

All reported cases of AT/RT at the Department of Pathology and Laboratory Medicine, Aga Khan University Hospital (AKUH) from 2007 to 2016 were reviewed for clinical and pathological features. Immunohistochemical stain for INI-1 was performed in all 11 cases. Follow up was obtained.

Results:

A total of 11 cases were identified. Seven patients were males and 4 were females. The ages ranged from 1 month to 48 months (mean 26.6 months). Six tumors were located in the cerebrum and 3 in the posterior fossa. Exact Location was not known in 2 cases. Histologically, rhabdoid cells were present in sheets in variable proportions in five cases, Medulloblastoma and PNET like areas were seen in 2 cases each. Immunohistochemical stains EMA (10/10), vimentin (7/7), CKAE1/AE3 (8/9), and CD99 (3/4), GFAP (6/10), ASMA (3/4) and synaptophysin (3/4) were positive in varying proportions while desmin was negative in all 6 cases in which it was performed. All 11 tumors lacked immunoreactivity for INI-1 protein. Four patients died of disease with a follow up ranging from 5 to 24 months.

Conclusions:

AT/RT is a rare highly aggressive embryonal tumor of CNS. A male predominance was noted in our series. We report the first and largest series from Pakistan.

Long-term survival following additive radiotherapy in patients with atypical teratoid rhabdoid tumors

BACKGROUND

Atypical teratoid rhabdoid tumor (ATRT) is a highly aggressive disease of embryonic origin accounting for <5% of all pediatric central nervous system (CNS) tumors.

PATIENTS AND METHODS

We describe a series of five cases of CNS ATRT. The first three patients underwent subtotal tumor resection. Gross total resection of the tumor was achieved in the fourth and fifth patients. Only 4 patients received chemotherapy, whereas all 5 patients received additive radiotherapy (RT). The latter included three dimensional (3D) conformal RT or intensity modulated RT (IMRT) with a median dose of 54 Gy (range 50.4-59.0 Gy) applied in daily fractions of 1.8 Gy. The median interval between surgery and RT was 5 months (range 2-11 months).

RESULTS

Two months after completion of RT, 4 patients had achieved complete radiologic remission. The median event-free survival period was 46 months (range 10-90 months). However, the first patient died 17 months after developing an out-of-field recurrence. The third patient developed a recurrence 11 months after salvage RT. The other 3 patients (cases 2, 4, and 5) remain alive with no evidence of disease 59, 46 and 90 months after therapy, respectively.

CONCLUSION

Overall, the 5 patients survived for a median of 48 months (range 25-90 months) from the time of initial diagnosis and they tolerated the RT well, without severe acute or late onset toxicities. The results imply a potential survival gain after irradiation at acceptable toxicity level.

Atypical teratoid/ rhabdoid tumor, an immunohistochemical study of potential diagnostic and prognostic markers

Atypical teratoid/rhabdoid tumor (AT/RT) is a rare tumor of the CNS mostly seen in infants and is often associated with a dismal outcome. Despite the heterogeneous morphology and/or immunoprofile, its diagnosis nowadays relies on the negative INI-1/BAF47 nuclear immunostain in tumor cells. We aim to investigate a number of immunohistochemical antibodies as potential diagnostic and prognostic markers. All AT/RT cases in patients younger than 18 years of age were included. Demographics, clinical features and outcome were collected. Immunostains tested included SALL-4, OCT3/4, CD99, FLI-1, cyclin-D1, β-catenin, P53, P16, CDX2 and WT-1. Nineteen cases (10 males) were identified at our center between 2004-2013 with a median age of 24 months. Ten (52.6%) cases were supratentorial. Six (42.9%) cases showed metastasis at time of presentation. Chemotherapy was administered to 10 (62.5%) and radiotherapy to seven (43.8%). The median overall survival was 11 months. A single long-term survival of 104 months was identified. Pathologically, most cases showed an admixture of rhabdoid cells and/or small cells and/or pale cells in variable proportions. Of all tested antibodies, only positivity for FLI-1 was associated with improved survival (P = 0.0012), while positivity for cyclin-D1 showed a trend toward improved survival (P = 0.0547). CDX2 was positive only in the single long-term survival. Interestingly, two cases showed co-expression of CD99 and FLI-1, and some were positive for SALL-4. In conclusion, FLI-1 and cyclin-D1 are potential prognostic markers associated with better outcome. Occasional AT/RT cases might co-express CD99 and FLI-1 as well as SALL-4, a potential diagnostic pitfall with Ewing sarcoma/ primitive neuroectodermal tumors and germ cell tumors, respectively.

Atypical Teratoid Rhabdoid Tumor in a Teenager with Unusual Infiltration Into the Jugular Foramen

BACKGROUND

Atypical teratoid rhabdoid tumor is a rare malignant neoplasm that represents 1%-2% of all pediatric central nervous system tumors. Immunohistochemistry plays an important role in establishing the diagnosis with a loss of INI-1 staining in tumor cells. In this case report, we describe a teenager with an unusual presentation and pattern of infiltration of the tumor.

CASE DESCRIPTION

A 13-year-old boy presented with a history over several months of progressive nausea, weight loss, and hoarseness of voice associated with multiple lower cranial nerve palsies on neurologic examination. Magnetic resonance imaging revealed a large heterogeneously enhancing extra-axial neoplasm with extension and bony expansion of the jugular foramen. After near total resection, neuropathology demonstrated the absence of INI-1 expression consistent with a diagnosis of atypical teratoid rhabdoid tumor.

CONCLUSIONS

This case highlights the diverse clinical presentation and infiltrative potential of atypical teratoid rhabdoid tumors, thus expanding the differential diagnosis of extra-axial tumors invading the jugular foramen.

[Molecular methods in diagnosis of poorly differentiated malignant brain tumors in children]

The histological diagnosis of malignant brain tumors in children is a complex process. In some cases, glioblastoma, primitive neuroectodermal tumor of the central nervous system, and atypical teratoid/rhabdoid tumor have a histological type similar to that of small blue round cell malignant tumor. Despite the similar histology, biological properties and approaches to treatment, these neoplasms are completely different and require their own treatment protocols. We retrospectively reviewed the most malignant types of childhood tumors and analyzed our own experience to propose a diagnostic algorithm for intracerebral small blue round cell malignant tumors in children based on the use of immunohistochemistry and fluorescence in situ hybridization.

Atypical teratoid/rhabdoid tumor (ATRT) arising from the 3rd cranial nerve in infants: a clinical-radiological entity?

Atypical teratoid/rhabdoid tumor (ATRT) is a rare embryonal tumor of the central nervous system with preponderance in very young children, the majority of whom are younger than 3 years of age at diagnosis. Historically, outcomes of this aggressive disease, even with extensive multimodal therapy, have been dismal. Recent improvements have come from therapies directed exclusively towards ATRT, but misdiagnosis or delays in the correct diagnosis lead to significantly worse survival rates. ATRTs most commonly occur supratentorially but have been described in virtually all central nervous system locations, including the cerebellopontine angle cistern, meninges, and spinal canal, and extradural locations. ATRTs originating from cranial nerves are rare. Here, we describe three cases of solitary ATRT arising from the 3rd cranial nerve (CN III) or close to its origin in the midbrain, all of which presented in patients within 6 months of birth, with isolated unilateral oculomotor nerve palsy and strikingly similar magnetic resonance imaging (MRI) features. These MRI features include IV contrast enhancement, relative T2 hyposignal, and restricted water diffusion on apparent diffusion coefficient images, findings which are consistent with angiogenesis and high cellularity, and hence, suggestive of malignancy. We conclude that ATRT should be placed high on the differential diagnosis list when encountering a young infant presenting with isolated, unilateral 3rd nerve palsy and a small, solitary tumor arising from CN III that demonstrates malignant conventional and diffusion-weighted imaging features on MRI.

Adult-onset sellar and suprasellar atypical teratoid rhabdoid tumor treated with a multimodal approach: a case report

We report a very rare case of sellar and suprasellar atypical teratoid rhabdoid tumor (ATRT) in a 42-year-old female patient. The tumor was removed subtotally with a transsphenoidal approach. Histopathologic study showed rhabdoid cells with prominent nucleoli and abundant cytoplasm. Immunohistochemistry for INI1 was completely negative in the tumor cells, consistent with ATRT. After surgery, she received radiotherapy including spinal irradiation with proton beam therapy and subsequent chemotherapy, with no evidence of recurrence for more than 2 years. Up to date, this is the 8th case of an adult-onset ATRT in the sellar or suprasellar region. Despite its rarity, ATRTs should be considered in the differential diagnosis of an unclear malignant sellar or suprasellar lesion in adult patients and the treatment strategies for adult ATRT patients could be differentiated from those of pediatric ATRT patients.

Differential SALL4 immunoexpression in malignant rhabdoid tumours and epithelioid sarcomas

AIMS

Malignant rhabdoid tumours (MRTs) and epithelioid sarcomas (ESs) are distinctive malignant neoplasms with characteristic clinicopathological features. However, these two tumour types share some phenotypic features, such as epithelioid/rhabdoid cytology, expression of epithelial markers, and immunohistochemical loss of INI1. The distinction can be problematic in atypical clinical settings, and ancillary diagnostic tools are needed. The expression of CD34 is widely cited as favouring the diagnosis of ES, but no formal comparative study has been performed in the post-INI1 era. Here, we evaluated the utility of SALL4 for differentiating MRTs from ESs, and compared its performance with that of CD34.

METHODS AND RESULTS

Fifteen MRTs and 36 ESs were retrieved. All MRTs and ESs lacked INI1 reactivity, except for one MRT that lacked BRG1. A representative slide from each case was stained using antibodies against SALL4 and CD34. Ten (67%) of the 15 MRTs expressed SALL4. In contrast, only one (3%) of the 36 ESs expressed SALL4. CD34 staining was observed in nine (60%) of the MRTs and 29 (81%) of the ESs.

CONCLUSIONS

Despite moderate sensitivity, SALL4 expression may aid in distinguishing MRTs from ESs. CD34 was found to have questionable utility in making such distinctions.

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

Background:

Atypical teratoid/rhabdoid tumor (AT/RT) is a rare central nervous system tumor composed of primitive rhabdoid cells that may differentiate along neuroectodermal, mesenchymal and epithelial lineages. AT/RT in adults is rare but not completely exceptional. It generally arises from the posterior fossa of infants, but the broad majority of the reported AT/RT in adults manifested supratentorially with the exception of four cases that arose in the cerebellum and two that arose in the spinal cord.

Case Description:

A 44-year-old female complained of visual disturbance. We performed craniotomies twice and removed partially for each time, but any malignant cells were not found in the specimens. Finally, we determined histological diagnosis from the extended lesion. She died of respiratory failure 17 months after the initial treatment.

Conclusion:

AT/RT should be considered in the differential diagnosis of a sellar lesion in adult patients. However AT/RT is rare in adults, the appropriate immunohistochemical evaluation should be performed to diagnose this rare entity.

Radiological image features of the atypical teratoid/rhabdoid tumor in adults: a systematic review

PURPOSE

Atypical teratoid/rhabdoid tumor (AT/RT) occurs in children less than 3 years old, and has a very poor prognosis. AT/RT seldom occurs in adult. We have experienced four cases of AT/RT at our institute. The purpose of this study is to evaluate the radiological image findings of adult-onset AT/RT and to conduct a systematic review.

METHODS

Image findings of four AT/RTs in our institute were retrospectively evaluated by an experienced neuroradiologist. If the images were unavailable, image findings were evaluated from the former image interpretation report. We assembled papers of adult-onset AT/RT (n = 38) and evaluated the image findings.

RESULTS

AT/RT occurs in a variety of sites (spinal region, pineal region, suprasellar region, jugular foramen, and so on). High density on computed tomography (CT) was seen in 10 of 11 cases; mixed intensity in T2-weighted image was seen in 13 of 18 cases; and high intensity on diffusion-weighted image (DWI) was seen in 3 of 3 cases. Contrast enhancement was observed in all cases in which images were available.

CONCLUSIONS

We have experienced four adult-onset AT/RT cases at our institute and have evaluated image findings through systematic review. The image findings of high density on CT, high intensity on DWI, with low apparent diffusion coefficient, and a heterogenous component should lead to an inclusion of AT/RT in the differential diagnosis of a tumor; these findings may be able to suggest AT/RT; however, they cannot make the diagnosis.

Sella turcica atypical teratoid/rhabdoid tumor complicated with lung metastasis in an adult female

Here we present the case of a 60-year-old woman with a rare sellar region atypical teratoid/rhabdoid tumor (AT/RT), complicated by lung metastasis and treated with neurosurgery, radiotherapy, and chemotherapy. The patient had recurrent headache associated with left cavernous sinus syndrome after a previous endonasal transsphenoidal resection for a presumptive pituitary macroadenoma. Pituitary magnetic resonance imaging showed a tumor regrowth in the original location with a haemorrhagic component involving the left cavernous sinus. A near complete transsphenoidal resection of the sellar mass was performed followed by 3 months of stereotactic radiotherapy. Because of a worsening of the general clinical conditions, respiratory failure, and asthenia, the patient underwent a contrast enhanced computer tomography of the whole body which showed the presence of lung metastasis. The histopathological diagnosis on samples from pituitary and lung tissues was AT/RT. The patient survived 30 months after diagnosis regardless chemotherapy. In the adult, the AT/RT should be considered as a possible rare, aggressive, and malignant neoplasm localized in the sella turcica.

Primary supratentorial atypical teratoid/rhabdoid tumor in children: a report of two cases

Atypical teratoid/rhabdoid tumor is a highly malignant tumor of the central nervous system, usually occurring in the posterior fossa in infants and young children. Supratentorial example is relatively rare, especially with involvement of the cerebral ventricle system. Herein, we reported 2 cases of atypical teratoid/rhabdoid tumor located in the septum pellucidum within the lateral and third ventricles and right parietooccipital region, respectively. Histopathologically, both of the tumors were composed of rhabdoid tumor cells and mesenchymal components, without primitive neuroectodermal tumor or epithelial differentiation. Immunohistochemical staining showed that these tumor cells reacted positively for vimentin, S-100 protein, synaptophysin, and neuron-specific enolase. Only 1 case was found to be epithelial membrane antigen reactive. The tumor cells lacked nuclear expression of INI1. These cases emphasize that atypical teratoid/rhabdoid tumor should be also considered in the list of differential diagnosis, even when these rhabdoid tumor cells do not arise in the predilection sites.

Peritoneal metastasis of third ventricular atypical teratoid/rhabdoid tumor after VP shunt implantation for unexplained hydrocephalus

BACKGROUND

Atypical teratoid/rhabdoid tumor (AT/RT) of the central nervous system (CNS) is a highly malignant neoplasm seen frequently in infancy and early childhood. This report presents a 9-year-old girl of primary third ventricular AT/RT with peritoneal metastasis after ventriculoperitoneal (VP) shunt catheter implantation for hydrocephalus before the identification of the CNS tumor.

METHODS

The data of clinical course, laboratory and imaging studies were obtained and carefully reviewed. Serial imaging studies including enhanced CT and MRI were performed at the first admission, during which the patient was diagnosed with a non-malignant communicating hydrocephalus. Secondary radiological studies were carried out 5 months after VP shunt, during which the patient demonstrated worsening clinical signs of intracranial hypertension. An imaging study identified a tumor in the third ventricle.

RESULTS

The patient was treated by a surgical resection, showing the specimen was pathologically consistent with AT/RT 5 months after VP shunt. Systematic chemotherapy and radiotherapy were prescribed for the patient. After 6 months, PET/CT revealed peritoneal metastasis but negative findings in the CNS. The parents of the patient refused further intervention, and she died one month later.

CONCLUSION

VP shunt in a patient with AT/RT may cause distant seeding of the tumor in unrelated areas of the body, even after intensive multimodality treatment. Further studies on shunt related metastases are needed.

Atypical teratoid/rhabdoid tumor with 26-year overall survival: case report

Atypical teratoid/rhabdoid tumor (AT/RT) is an aggressive embryonic brain tumor predominantly seen in young children. The authors report an unusual case of a fourth ventricle AT/RT in an infant who survived for 26 years. The tumor was resected when the patient was 6 months of age, and radiation therapy (40-Gy total dose) was performed thereafter. The patient was free from the disease for 26 years until a recurrent tumor was found in the spinal cord. The spinal cord neoplasm was a "collision tumor" with 2 components: benign schwannoma and recurrent AT/RT. The patient died of dissemination of the recurrent tumor 5 months after it was excised. This is the longest survival of a patient with AT/RT ever reported and indicates that long-term survival, more than 20 years, can be achieved in infantile-onset AT/RT. Despite intensive treatment, the prognosis for AT/RT is very poor, especially in children younger than 3 years of age. The benefits of upfront radiation therapy for AT/RT should be carefully assessed with respect to its inevitable toxicity in very young children. However, early upfront radiation therapy may be of therapeutic interest to prevent aggressive progression of the disease.

Malignant brain tumor with rhabdoid features in an adult

Rhabdoid tumor (RT) of the central nervous system is an uncommon and aggressive neoplasm that usually affects pediatric patients. Currently, these tumors are classified as malignant RT or atypical teratoid/RT. Another entity of intraparenchymal brain tumor with a rhabdoid component is the extremely rare rhabdoid glioblastoma. A 23-year-old woman presented with a malignant RT in the right thalamus. The tumor was adjacent to the right lateral ventricle and was partially resected. Histological examination revealed prominent proliferation of rhabdoid cells, which is consistent with a diagnosis of malignant RT; the typical features of glioblastoma were not observed. The tumor cells stained positively for integrase interactor-1 and glial fibrillary acidic protein. Therefore, the tumor may have originated from glial components. Genetic analysis using comparative genomic hybridization showed a deoxyribonucleic acid copy-number gain on chromosome 7 but not on chromosome 22. The tumor did not respond to chemotherapy or radiotherapy, and the patient survived for only 4 months after surgery. The present case of malignant RTs shows certain similarities with those of rhabdoid glioblastoma. Further accumulation and analysis of data, including data from genetic analyses, may lead to the identification of a new type of malignant RT.

Atypical teratoid/rhabdoid tumors in adults: a case report and treatment-focused review

Atypical teratoid/rhabdoid tumor is predominantly a childhood tumor and has only been rarely reported in adults; therefore, treatment regimens are often extrapolated from the pediatric experience. Typically, children are treated with craniospinal radiation therapy which is often followed by systemic chemotherapy. Employing pediatric regimens to treat this tumor in adult patients poses a particular risk for myelosuppression, as the prescribed doses in pediatric protocols exceed those tolerated by adults, and conventional craniospinal radiation can be associated with prolonged myelotoxicity and a depletion of the bone marrow reserve in vertebrae of adults. Here we present a case of a woman with a pineal region atypical teratoid/rhabdoid tumor, an unusual adult cancer presenting in an atypical location. This is followed by a review of the disease in adult patients with an emphasis on treatment and suggestions to minimize myelotoxicity.

Clinicopathologic comparison of familial versus sporadic atypical teratoid/rhabdoid tumors (AT/RT) of the central nervous system

BACKGROUND

Central nervous system (CNS) atypical teratoid/rhabdoid tumors (AT/RT) are aggressive tumors usually diagnosed in young children and characterized by SMARCB1 (INI1, hSNF5) gene abnormalities. Despite initial chemo-radiation responsiveness, most children die of progressive disease (PD). Little data regarding familial AT/RT clinical course exist. This study described and compared familial (F) versus sporadic (S) AT/RT and elucidated SMARCB1 mutations and inheritance patterns.

METHODS

A retrospective chart review, pedigree, and SMARCB1 analysis were done.

RESULTS

Between January 1989 and June 2009, 20 children with CNS AT/RT were diagnosed, 8-S and 12-F. Median age at diagnosis (months) of S and F patient were: 13 and 4.8, respectively. Median survival (months) was S-21, F4.5, and 8-all. Pedigree analyses showed unaffected parent carriers with multiple affected offspring.

CONCLUSIONS

Children with F-AT/RT are younger, have more extensive disease, and are more likely to die from PD than children with S-AT/RT. Surgery, radiation, and chemotherapy were important in achieving long-term survival. Pedigree analysis supports autosomal dominant inheritance pattern with incomplete penetrance. Germline SMARCB1 mutation analysis is important in all patients diagnosed with AT/RT to (1) determine actual incidence of F-AT/RT, (2) determine penetrance of predisposing mutations, (3) provide appropriate genetic counseling, and (4) establish surveillance screening guidelines.