Atypical teratoid/rhabdoid tumor of the pineal region in an adult

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.

Atypical teratoid/rhabdoid tumour with CDK6 amplification in a child: a case report and literature review

Atypical teratoid/rhabdoid tumours (AT/RTs) are rare central nervous system neoplasms that frequently occur in infants and children and have a very poor prognosis. In recent years, molecular analysis of AT/RTs has shown that biallelic inactivation of SMARCB1 (INI1, SNF5, BAF47) or SMARCA4 (BRG1) frequently occurs. Here, we present a case of basal ganglia AT/RT with SMARCB1 gene deficiency and CDK6 gene amplification in a 5-year-old child. A 5-year-old boy was hospitalized due to a 1-week history of frontal and parietal headache. Magnetic resonance imaging (MRI) demonstrated a 3 cm × 2 cm × 1.5 cm heterogeneous enhanced mass located at the right basal ganglia that partially protruded into the right lateral ventricle. The lesion was successfully resected under electrophysiological monitoring and neuronavigation. The postoperative pathological examination implied an AT/RT diagnosis, with loss of SMARCB1 protein, SMARCB1 gene deficiency and CDK6 gene amplification. Unfortunately, the patient died due to respiratory and circulatory failure at 5 weeks after the operation. To date, standard regimens have not yet been established due to the lack of large-scale prospective studies for AT/RT. The p16-RB signalling pathway should be considered as a potential target for AT/RT treatment modalities. Apart from traditional regimens, targeted therapies, especially CDK4/6 inhibitors, are likely a promising therapeutic option for AT/RT treatment.

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.

Malignant Extrarenal Rhabdoid Tumor of the Vagina on FDG PET/CT

ABSTRACT

Malignant rhabdoid tumor is an aggressive neoplasm commonly arising from the kidney during infancy and childhood. Extrarenal forms of this tumor are relatively rare and have been reported in several extrarenal sites including central nervous system, liver, bladder, vulva, and head and neck. Hereby, we present FDG PET/CT findings of malignant extrarenal rhabdoid tumor originating from the vagina in an 8-year-old girl.

SMARCB1/INI1-deficient tumors of adulthood

The SMARCB1/INI1 gene was first discovered in the mid-1990s, and since then it has been revealed that loss of function mutations in this gene result in aggressive rhabdoid tumors. Recently, the term "rhabdoid tumor" has become synonymous with decreased SMARCB1/INI1 expression. When genetic aberrations in the SMARCB1/INI1 gene occur, the result can cause complete loss of expression, decreased expression, and mosaic expression. Although SMARCB1/INI1-deficient tumors are predominantly sarcomas, this is a diverse group of tumors with mixed phenotypes, which can often make the diagnosis challenging. Prognosis for these aggressive tumors is often poor. Moreover, refractory and relapsing progressive disease is common. As a result, accurate and timely diagnosis is imperative. Despite the SMARCB1/INI1 gene itself and its implications in tumorigenesis being discovered over two decades ago, there is a paucity of rhabdoid tumor cases reported in the literature that detail SMARCB1/INI1 expression. Much work remains if we hope to provide additional therapeutic strategies for patients with aggressive SMARCB1/INI1-deficient tumors.

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.

A 71-year-old man with a rare rhabdoid brain tumour: using a multidisciplinary medical and rehabilitative model of care

Atypical rhabdoid tumours (AT/RTs) of pineal origin are rare in adults with rapid progression and poor prognosis. We present the case of a 71-year-old man with confusion and memory loss who was diagnosed with a pineal AT/RT after genetic analysis. Due to his limited functional capacity and goal to return home with family, a multidisciplinary care approach was essential for coordination of medical management, radiation treatment and acute inpatient rehabilitation. After diagnosis and rehabilitation, his functional ability improved allowing him to tolerate cranial irradiation, initiate systemic chemotherapy and eventually returned home for a brief period with an improved quality of life. His progress was temporary due to rapid progression of the tumour. He required additional aggressive oncological treatment and was admitted for subsequent inpatient rehabilitation before opting for hospice care. This case underscores the importance of a multidisciplinary approach to cancer treatment in a patient with a rare and aggressive brain tumour, while respecting the individual goals of patients and their families.

Pineal Atypical Teratoid Rhabdoid Tumor in a 5-Month-Old Child

INTRODUCTION

Atypical teratoid rhabdoid tumors (ATRT), an uncommon malignant intracranial tumor with aggressive behavior are mostly seen in posterior fossa in young pediatric age-group.

CASE PRESENTATION

We present an infrequent location of this tumor in the pineal region in a 5-month-old infant. Also, the lesion was non-enhancing which was highly atypical of an ATRT. It was near-totally excised with the child placed in sitting position. However, within a short interval, a tumor recurrence was noted.

CONCLUSION

The case possibly represents an extended spectrum of congenital childhood brain tumors. Importantly, it highlights an atypical imaging of ATRT in very young children.

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.

Multimodal treatments combined with gamma knife surgery for primary atypical teratoid/rhabdoid tumor of the central nervous system: a single-institute experience of 18 patients

OBJECTIVES

Atypical teratoid/rhabdoid tumor (AT/RT) is a rare, highly malignant tumor of the central nervous system with poor prognosis. Nowadays, multimodal management, including surgery, chemotherapy (CMT), and radiation therapy (RT), is advocated. However, AT/RT treatment with gamma knife surgery (GKS) was rarely reported. The aim of this study was to assess the efficacy and safety of GKS for the treatment of AT/RT.

PATIENTS AND METHODS

Medical records of AT/RT patients who underwent surgery from 2007 to 2014 at the West China Hospital were retrospectively reviewed and statistically analyzed.

RESULTS

Eighteen patients (12 males and 6 females) were presented with AT/RTs. Median age during presentation was 20.5 months (range, 4-179 months). Twelve patients were < 3 years and six patients were > 3 years. Tumor location was supratentorial in seven patients, infratentorial in ten patients, and center area of the brain in one patient. Treatments performed were as follows: surgery alone in two patients, surgery+RT in two patients, surgery+CMT in five patients, surgery+CMT+RT in two patients, and surgery+CMT+RT+GKS in seven patients. The 2-year overall survival (OS) rate and event-free survival (EFS) rate for all 18 consecutive patients were 33.3 and 27.8%, respectively. Cox regression analyses showed that multimodal management combined with GKS was an independent positive prognostic factor for OS.

CONCLUSIONS

Although AT/RTs are lethal cancer types, the OS of the disease was improved by using multimodal therapeutic strategies, including surgery, CMT, and RT, combined with GKS.

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.

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.

[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.

Primary Intracranial Atypical Teratoid/Rhabdoid Tumors: A Clinicopathologic and Neuroradiologic Study

Atypical teratoid/rhabdoid tumors are rare malignant pediatric brain tumors. This study was performed to characterize the clinicopathologic and neuroradiologic characteristics of atypical teratoid/rhabdoid tumors from 8 patients, including 5 male and 3 female infants (median age, 67 months). Neuroimaging revealed bulky masses of heterogeneous intensity with inhomogeneous enhancement. Three cases were infratentorial and 5 were supratentorial. Histopathologically, the tumors were predominantly composed of rhabdoid cells and undifferentiated small cells, mixed with some spindle or epithelial components. The tumors displayed striking polyphenotypic immunoreactivity, including varying degrees of positivity for vimentin, epithelial membrane antigen, smooth-muscle actin, cytokeratin, glial fibrillary acidic protein, neurofilament protein, synaptophysin, and CD99, and immunonegativity for desmin, placental alkaline phosphatase, and INI-1. The median survival duration was 9.5 months (range, 1-15 months) despite aggressive therapy. These results suggest that atypical teratoid/rhabdoid tumors display distinct clinicopathologic characteristics and indicate a poor prognosis. Immunohistochemistry facilitates the appropriate diagnosis of these tumors.

Survival rates, prognostic factors and treatment of anaplastic meningiomas

Intracranial anaplastic meningioma is a malignant type of meningioma with a high rate of recurrence and death. Given its rarity, minimal information regarding this tumour is available. Thus, we studied a series of patients with anaplastic meningiomas and analysed the survival rates, prognostic factors and treatment methods associated with these patients. Forty-three anaplastic meningioma cases treated at our hospital between July 2002 and June 2012 were compiled into a single database used to summarise the clinical characteristics from a retrospective review of patient records. Progression free survival (PFS) and overall survival (OS) were analysed as a function of each possible prognostic factor. The 1, 3 and 5 year PFS rates were 90.7%, 51.3%, and 37.0%, respectively, whereas the corresponding values of OS rates were 95.3%, 68.0% and 49.2%, respectively. A number of factors were selected to analyse association with prognosis. Simpson Grade I and II resections exhibited increased PFS rates and radiotherapy improved the OS rate in anaplastic meningiomas. Tumours with homogeneous contrast enhancement on MRI were associated with increased PFS and OS. Sex, age, tumour location, first or transformed anaplastic tumour, pre-operative Karnofsky Performance Scores, tumour volumes and bone involvement had no significant effect on either PFS or OS. MRI homogeneous contrast may be a useful prognostic factor and surgery followed by radiotherapy is recommended for the treatment of anaplastic meningiomas.

Long-term survival analysis of atypical meningiomas: survival rates, prognostic factors, operative and radiotherapy treatment

BACKGROUND

The rarity and the inconsistent criteria for defining atypical meningioma prior to the WHO 2007 classification made its management and prognostic factors poorly understood. Only few articles have addressed the survival rates of WHO-classified atypical meningiomas. The small number or the disproportionate representation of irradiated patients was a weakness for these articles. This study evaluated whether the extent of surgery and receiving adjuvant radiotherapy after an initial operation along with other patient characteristics influenced the recurrence and survival rates of atypical meningiomas.

METHODS

The clinical and surgical notes of the 79 patients with grade II atypical meningioma treated at our center over 13 years were retrospectively evaluated. The histology grading was consistent with WHO 2007 classification. The Simpson grading system was used to assess the extent of surgical resection. Kaplan Meier analysis, Cox multivariate regression analysis, and the Log-rank test were conducted using STATA® statistical package.

RESULTS

The average age at the time of initial operation was 58 years, and 54 % were males. The mean follow-up period was 50 months. In Cox multivariate analysis, only Simpson grading was predictive of recurrence (hazard ratio = 2.22 / 1 increase in Simpson grade. p = 0.003). Simpson grade I patients had a relapse-free survival rate of 97 and 74 % at one and five years, respectively, compared with 88 and 32 % in the subtotal resection group (Simpson grades II to IV). There was no statistically significant correlation between recurrence and subjecting patients to postoperative radiotherapy. Apart from Simpson grade I patients, there was a general trend for worse outcome in irradiated patients.

CONCLUSIONS

The most important prognostic factor in determining recurrence was Simpson grading. There was no statistically significant impact of adjuvant radiotherapy on the recurrence of atypical meningiomas. Meta-analysis for the existing literature is needed.

Malignant rhabdoid tumor of the floor of mouth: first reported case in the oral cavity of an adult

Malignant rhabdoid tumors (MRTs) are exceedingly rare lesions. To our knowledge, only 2 cases have been reported in the oral cavity, with both examples occurring in infants. The current case is the third reported case of MRT of the oral cavity and the first reported case to occur in an adult at this location. The following report describes the clinical, histologic and immunohistochemical features of this tumor.

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.

Atypical teratoid rhabdoid tumor located in the pineal region following prophylactic irradiation for acute lymphoblastic leukemia

Atypical teratoid rhabdoid tumor (AT/RT) is a rare entity. In the central nervous system, AT/RT generally arises from the posterior fossa of infants and behaves aggressively. AT/RT is reported to arise from the infratentorial region (63%) and other sites, such as the suprasellar region, cerebellopontine angle, and spinal cord. The pineal region is rare (6%) as a site of origin. Radiation-induced brain tumors are well known. In this report, we present a case of a pineal region tumor causing acute hydrocephalus that could be pathologically diagnosed as AT/RT following prophylactic cranial irradiation for acute lymphoblastic leukemia.