Survival Benefit from Multimodal Treatment for Patients with Atypical Teratoid Rhabdoid Tumor in a Surveillance, Epidemiology, and End Results Database Analysis.

INTRODUCTION: Atypical teratoid rhabdoid tumor (ATRT) is among the most aggressive central nervous system malignancies. Although rare, this tumor typically afflicts young children and results in mortality within months. Here, we aim to determine key clinical features and treatment options that impact the survival of patients with ATRT. METHODS: From the year 2000 to 2019, 363 patients with ATRT were identified from the Surveillance, Epidemiology, and End Results database. Univariate analysis was used to identify variables that had a significant impact on the primary endpoint of overall survival (OS). Multivariable analysis was then used to identify independent predictors of survival. RESULTS: The median OS of the entire cohort was 13 months. Univariate analysis identified ages between 1 and 3 years, ages between 4 and 17 years, years of diagnosis between 2010 and 2019, and the receipt of treatment to have a significant impact on survival. In multivariable analysis, ages between 1 and 3 years and receipt of treatment were the only significant independent predictors of survival. The median OS was significantly greater in patients who received surgical treatment, chemotherapy, or radiation when compared to those who did not receive any treatment. In general, the receipt of any combination of therapies improved the median OS significantly. The receipt of triple therapy had the greatest impact on survival. DISCUSSION: This study highlights the survival benefit of a multimodal approach in the treatment of ATRT. The use of triple therapy, including surgery, radiation, and chemotherapy, was found to have the greatest survival benefit for patients. Overall, these findings may guide future care for patients with ATRT.

Paediatric Rhabdoid Meningioma: Clinical and Therapeutic Features Findings - Case Series of 3 Patients.

INTRODUCTION: Paediatric rhabdoid meningioma (RM) is the rarest but most aggressive subtype of meningioma, related to a severe prognosis. They account for 1-3% of all intracranial meningiomas. CASE PRESENTATIONS: We report an institutional experience of 3 cases through which we discuss clinical, histological, and therapeutic features of this tumour. Two of our patients were female-gendered (3 years old and 1 year and 6 months old), and one was male-gendered (16 years old). Revealing symptoms were related to intracranial hypertension, cerebellar syndrome, cranial nerve palsy, and skull tumefaction. Imaging showed extra-axial tumour located in the right ponto-cerebellar angle in the first case, in the left occipital region in the second case, left parietal tumour in the third case. All patients underwent a surgical intervention with a gross total resection. Histological evaluation supported by immunohistochemistry confirmed the diagnosis of RM. Tumour recurrence was observed at 45 days in the first case with a fatal outcome. Despite adjuvant radiotherapy, both second and third cases had local recurrence after a mean follow-up of 1 month following the radiotherapy. CONCLUSIONS: RM is very aggressive tumours. Standardized therapeutic guidelines are still under debate as actual approaches are still inefficient to prevent quick recurrence and fatal outcome.

Associating liver partition and portal vein ligation for staged hepatectomy as bridging therapy for liver transplantation in an infant with an advanced hepatic rhabdoid tumor.

BACKGROUND: Malignant rhabdoid tumors (MRTs) are rare, aggressive tumors that mainly affect children and currently lack effective chemotherapeutic regimens. Liver MRTs are particularly challenging to manage due to the difficulty of performing one-stage liver resection, and preemptive liver transplantation is associated with high recurrence rates. However, the associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) technique offers a promising surgical approach for advanced-stage liver tumors where conventional liver resection is not feasible. CASE REPORT: A patient with a large liver rhabdoid tumor that had invaded the three main hepatic veins underwent four courses of cisplatin-pirarubicin chemotherapy. ALPPS was performed due to insufficient residual liver capacity, with hepatic parenchymal dissection between the anterior and posterior liver zones in the first stage of surgery. After confirming adequate remaining liver volume, the liver was resected except for S1 and S6 on postoperative day 14. LDLT was performed 7 months after ALPPS due to the gradual deterioration of liver function caused by chemotherapy. The patient was recurrence-free 22 and 15 months after ALPPS and LDLT, respectively. CONCLUSIONS: The ALPPS technique is a curative option for advanced-stage liver tumors that cannot be managed with conventional liver resection. In this case, ALPPS was used successfully to manage a large liver rhabdoid tumor. Then, liver transplantation was performed after chemotherapy. The ALPPS technique should be considered a potential treatment strategy for patients with advanced-stage liver tumors, particularly those who can undergo liver transplantation.

Atypical teratoid rhabdoid tumours (ATRTs)-a 21-year institutional experience.

PURPOSE: Atypical teratoid/rhabdoid tumours (ATRTs) are malignant embryonal tumours of childhood that affect the central nervous system (CNS). We aim to determine which factors, including patient age, extent of resection (EOR), presence of distal metastasis and use of adjuvant therapies, affect overall survival in children with atypical teratoid/rhabdoid tumours (ATRTs) treated at this single centre. METHODS: Retrospective cohort review of patients with histological diagnosis of ATRT treated over 21 years (1999-2020) was conducted. Data on demographics, tumour location, presence of metastasis, use of adjuvant therapy, extent of resection (EOR), complications, neurological outcome post-surgery, and overall survival were collected. Kaplan-Meier survival analysis was performed. RESULTS: A total of 45 children (mean age 2 years) underwent 64 operations. 25 patients were <1 year of age. Gross-total resection (GTR) pre-adjuvant therapy was achieved in 15, near-total resection (NTR) in 15, subtotal resection (STR) in 9, and biopsy in 6 children. Most children had good neurological outcomes post-operatively (28/45 with GOS 5). Fourteen patients survived longer than 4 years. Survival analysis showed a significant difference in median survival in favour of GTR and localised disease. There was no significant difference in median survival between patients <1 year vs >1 year of age (p=0.84). CONCLUSION: We find that presence of metastasis was an important factor in poor survival in patients with ATRT. GTR, where possible, may confer significant survival benefit in ATRT. Children aged <1 year appear to have performed as well as those >1 year and therefore should still be considered for radical surgery.

Paediatric atypical teratoid/rhabdoid tumour of the pineal region mimicking a meningioma: a case report and literature review.

PURPOSE: Atypical teratoid/rhabdoid tumour (AT/RT) is a highly malignant central nervous system tumour of early childhood. According to the latest WHO classification, the diagnosis of AT/RTs needs to be confirmed by the absence of SMARCB1 (INI1) or SMARCA4 (BRG1) protein expression. AT/RT in the pineal region is infrequent and most have not been proven genetically. Here, we report a case of AT/RT in the pineal region, preoperatively misdiagnosed as a meningioma. Immunohistochemistry revealed the absence of INI1 protein expression. METHOD: A 29-month-old boy was admitted to the hospital after 14 days of emotional apathy and a 2-day vomiting history. AT/RT was not considered during the initial diagnosis because this tumour is rare in this region and is often accompanied by cystic degeneration and necrosis on imaging. Subsequently, the patient underwent surgery and the tumour was completely excised. RESULT: The pathological diagnosis was AT/RT. After discharge, the patient continued chemotherapy in other hospitals but died five months after surgery because of disease progression. CONCLUSION: To our knowledge, this is the fifth case of paediatric pineal AT/RT confirmed genetically. Although in children AT/RT in the pineal gland is rare, a differential diagnosis of AT/RT should be considered when new pineal masses appear in children. For this highly malignant disease with poor prognosis, it is very important to detect and recognize the disease as soon as possible, and to adopt surgery plus multiple treatment management.

Malignant rhabdoid tumor of the liver in a middle-aged woman: a case report and literature review.

BACKGROUND: Extrarenal malignant rhabdoid tumor (EMRT) is a rare and high-mortality malignant tumor, which is more common in infants and rarely seen in adults. We firstly report a case of liver malignant rhabdoid tumor (MRT) with a loss of SMARCB1 gene (alias INI1, SNF5, BAF47) expression in a middle-aged woman, and preliminarily summarize the clinical characteristics and discuss its potential treatment of liver MRT by reviewing 55 cases reported in the past. CASE PRESENTATION: We report a 40-year-old woman who was admitted to our hospital for right epigastric pain. Previously, the patient was treated with liver hematoma in another hospital until she came to our hospital for abdominal pain again. In our hospital, we performed surgical treatment on her and the pathology diagnosed EMRT with negative expression of SMARCB1. After surgery, the patient underwent genetic testing, but failed to screen for sensitive targeted or conventional chemotherapy drugs, and she did not receive further treatment. Due to lack of timely diagnosis and effective chemotherapy drugs, tumor recurrence and metastasis occurred one year after surgery. Then the patient chose traditional Chinese medicine for treatment. And the metastatic tumors had still progressed after one year of treatment, but the patient didn't have obvious discomfort symptoms. CONCLUSIONS: Liver MRT is a highly aggressive tumor with high metastatic potential and poor prognosis. It lacks specific symptoms and signs and is easy to be ignored and misdiagnosed. The mortality rate is extremely high as there is no effective treatment. But most tumors are accompanied by SMARCB1 deficiency, which may offer new research directions for cancer therapeutics. For the present, early detection, early diagnosis and early resection remain the key to improve the prognosis of patients.

Extra-axial, dural-based atypical teratoid/rhabdoid tumor.

Atypical teratoid/rhabdoid tumors (ATRTs) are malignant central nervous system tumors that affect early childhood (< 3 years), and mostly located in the infratentorial space. Owing to an infrequent occurrence, their radiological features have not been completely defined. Nevertheless, these are characteristically intra-axial except for few instances in the cerebellopontine angle region. We describe a case of a 10-year-old boy who harbored an extra-axial, dural-based ATRT in the right parietal region. The lesion was totally excised followed by adjuvant chemo-radiotherapy. At 10-month follow-up, he was well with no recurrence. The report intends to highlight an atypical imaging presentation of ATRT in an older child, and adds to the radiological spectrum. This uncommon pathology should be borne in mind, even in a supratentorial dural-based location.

Multidisciplinary management of pediatric malignant rhabdoid tumor based on 5 years of experience at a tertiary care center.

OBJECTIVE: Malignant rhabdoid tumor (MRT) is a highly aggressive tumor that occurs mostly in young children with extremely poor prognosis. Standardized and effective treatment strategies for MRT have yet to be established because of its rarity. Here, we report our single-institutional experience involving MRT treatment. METHODS: Patients with newly diagnosed MRT between March 2016 and October 2021 were included. The clinical characteristic, treatment-related toxicities, clinical outcomes, and prognostic factor were retrospectively analyzed. RESULTS: A total of 18 patients with MRT were enrolled during the 5 years. The median age was 42.8 months (range 10 to 82 years). Among the 18 patients, 9 patients died after a median of follow-up 26 months (range 3 to 42 months). The 1-year event-free survival (EFS) and 3-year overall survival (OS) rates of the entire cohort were 63% (95% CI 46% to 74%) and 67% (95% CI 49% to 82%), respectively. Univariate analysis of patients who underwent gross or total resection followed by adjuvant chemotherapy and radiotherapy demonstrated an improvement in 1-year EFS. However, only gross resection and total resection predicted a better 3-year OS. CONCLUSIONS: Surgical excision is still the mainstream treatment for MRT. Postoperative adjuvant treatments including chemotherapy and radiotherapy contribute to improved disease control rate. Our single-institute experience may provide insights into the multimodal treatment of MRT.

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.

Successful Multimodality Management of Atypical Teratoid/Rhabdoid Tumour of the Lower Dorsal Spine with Spinal Drop Metastasis: Illustrated Review.

INTRODUCTION: Spinal atypical teratoid/rhabdoid tumour (AT/RT) is exquisitely rare and constitutes 2% of all AT/RTs. CASE PRESENTATION: A 6-year-old boy presented with low backache for the last 5 months. MRI of the spine showed a 1.5 × 1.5 × 4.7 cm intradural extramedullary mass extending from D10 to D12, causing compression of the conus medullaris. With a preoperative diagnosis of ependymoma, a gross total resection (GTR) of tumour was performed. Post-operative histopathology showed AT/RT. The tumour cells were immunopositive for cytokeratin, epithelial membrane antigen, smooth muscle actin, and p53 and immunonegative for MIC2, desmin, glial fibrillary acidic protein, and INI1. Post-operative neuraxis MRI revealed post-operative changes (D10-D12) with a 9 mm enhancing lesion at L5-S1 junction suggesting drop metastasis. There was no lesion in brain. Cerebrospinal fluid cytology did not show any malignant cell. The metastatic work-up was normal. He received 3 cycles of chemotherapy with ICE regimen (ifosfamide, carboplatin, and etoposide). Subsequently, he received craniospinal irradiation (CSI)-36 Gy/20 fractions/4 weeks followed by focal boost to primary tumour bed and spinal drop metastasis-14.4 Gy/8 fractions/1.5 weeks. Thereafter, he received 3 more cycles of ICE regimen. End-of-treatment MRI spine showed post-op changes (D10-D12) and 38.9% reduction of the L5-S1 lesion suggesting partial response. Six monthly spinal MRI showed serial reduction of the metastatic lesion leading to complete response (CR) 1 year after completion of treatment. On last follow-up (30 months from the initial diagnosis), he was neurologically intact and in CR. CONCLUSION: Multimodality management comprising GTR of tumour, CSI followed by focal boost, and multiagent chemotherapy (ICE) can lead to successful outcome in patients with this rare and aggressive spinal tumour.

[Influence of resection quality on postoperative outcomes in children with atypical teratoid-rhabdoid tumor of the central nervous system]. / Vliyanie radikal'nosti operativnogo vmeshatel'stva na rezul'taty lecheniya atipichnoi teratoidno-rabdoidnoi opukholi tsentral'noi nervnoi sistemy u detei.

The purpose of this study was to assess the influence of resection quality on overall survival and disease-free survival in children with atypical teratoid-rhabdoid tumors (ATRT). The study included children younger than 18 years old for the period from 2008 to 2019. There were 134 interventions in 105 patients with ATRT including 11 redo resections («second-look¼ surgery) and 18 procedures for tumor recurrence. Age of patients ranged from 2 to 168 months (median 21 months). Patients with supratentorial tumors prevailed (50.5%), infratentorial neoplasms were diagnosed in 45.7% of patients, spinal cord lesion - 3.8% of cases. At the first stage, all patients underwent surgical treatment. Total resection was achieved in 34 (32.4%) patients, subtotal - 37 (35.2%) patients, partial resection - 30 (28.6%) patients. Biopsy was performed in 4 (3.8%) patients. Quality of resection and age at surgery significantly influenced overall and disease-free survival. Extended resection of tumor followed by adjuvant chemo- and radiotherapy are required to improve survival although ATRTs are high-grade neoplasms with poor prognosis.

Impact of sarcomatoid differentiation and rhabdoid differentiation on prognosis for renal cell carcinoma with vena caval tumour thrombus treated surgically.

BACKGROUND: Sarcomatoid differentiation in renal cell carcinoma (RCC) with vena caval tumour thrombus has been shown to be associated with aggressive behaviours and poor prognosis; however, evidence of the impact of rhabdoid differentiation on prognosis is lacking. This study evaluated the impact of sarcomatoid differentiation and rhabdoid differentiation on oncological outcomes for RCC with vena caval tumour thrombus treated surgically. METHODS: We retrospectively analysed patients treated surgically for RCC with vena caval tumour thrombus at our institute from Jan 2015 to Nov 2018. Prognostic variables were evaluated for associations with progression-free survival (PFS) and cancer-specific survival (CSS) by Kaplan-Meier survival analysis and log-rank test. Univariate and multivariate analyses were performed to determine independent prognostic variables. RESULTS: We identified 125 patients with RCC and vena caval tumour thrombus, including 17 (13.6%) with sarcomatoid differentiation alone, 8 (6.4%) with rhabdoid differentiation alone and 3 (2.4%) with both sarcomatoid and rhabdoid differentiation. Compared to pure RCC, patients with sarcomatoid differentiation but not rhabdoid differentiation have worse PFS (p = 0.018 and p = 0.095, respectively). The univariate and multivariate analyses both showed sarcomatoid differentiation as a significant predictor of PFS. Compared to pure RCC, patients with sarcomatoid differentiation (p = 0.002) and rhabdoid differentiation (p = 0.001) both had significantly worse CSS. The univariate analysis showed sarcomatoid differentiation, rhabdoid differentiation, metastasis and blood transfusion as significant predictors of CSS (All, p < 0.05). In the multivariate analysis, sarcomatoid differentiation (HR 3.90, p = 0.008), rhabdoid differentiation (HR 3.01, p = 0.042), metastasis (HR 3.87, p = 0.004) and blood transfusion (HR 1.34, p = 0.041) all remained independent predictors of CSS. CONCLUSIONS: Sarcomatoid differentiation and rhabdoid differentiation are both independent predictors of poor prognosis in RCC with vena caval tumour thrombus treated surgically.

Outcomes with respect to extent of surgical resection for pediatric atypical teratoid rhabdoid tumors.

PURPOSE: To evaluate overall survival for atypical teratoid rhabdoid tumors (ATRTs) in relation to extent of surgical resection. METHODS: The neurosurgical tumor databases from three UK Pediatric centers (University Hospital of Wales, Alder Hey and Royal Manchester Children's Hospital) were analyzed. Patients with a diagnosis of ATRT were identified between 2000 and 2018. Data was collected regarding demographics, extent of resection, complications, and overall survival. RESULTS: Twenty-four patients diagnosed with ATRT underwent thirty-eight operations. The age range was 20 days to 147 months (median 17.5 months). The most common location for the tumor was the posterior fossa (nine patients; 38%). Six patients (25%) underwent a complete total resection (CTR), seven (29%) underwent a near total resection (NTR), eight (33.3%) underwent a subtotal resection (STR), and three patients (12.5%) had biopsy only. Two-thirds of patients who underwent a CTR are still alive, as of March 2019, compared to 29% in the NTR and 12.5% in the STR groups. Out of the thirty-eight operations, there were a total of twenty-two complications, of which the most common was pseudomeningocele (27%). The extent of surgical resection (p = 0.021), age at surgery (p = 0.00015), and the presence of metastases at diagnosis (0.015) significantly affected overall survival. CONCLUSIONS: Although these patients are a highly vulnerable group, maximal resection is recommended where possible, for the best chance of long-term survival. However, near total resections are likely beneficial when compared with subtotal resections and biopsy alone. Maximal surgical resection should be combined with adjuvant therapies for the best long-term outcomes.

Neoadjuvant chemotherapy for atypical teratoid rhabdoid tumors (AT/RTs).

PURPOSE: Atypical teratoid rhabdoid tumor (AT/RT) is a rare, clinically highly malignant tumor. The extent of the surgical resection may affect survival. However, it is often difficult to perform gross total resection (GTR) at an initial surgery because of the large tumor size and high vascularity. Neoadjuvant chemotherapy may reduce not only the size but also the vascularity. We report our experience, review the literature, and analyze its effectiveness. METHODS: A retrospective chart review of patients who underwent neoadjuvant chemotherapy and second-look surgery was performed. Demographic data, treatment courses, changes in tumor after the chemotherapy, extent of resection and estimated blood loss (EBL) during the second-look surgery, and outcome of each children were evaluated. RESULTS: There are 4 cases. The average age at diagnosis was 13.3 months (2-30 months). Two to 4 courses of neoadjuvant chemotherapy were performed. MRI after the chemotherapy showed reduction of tumor volume, and tumor vascularity at the second-look surgery decreased in all cases. GTR was achieved in 3 cases, and NTR in 1 case. The mean EBL/estimated blood volume (EBL/EBV) was 21.3% (1.5-39%). The mean follow-up period was 23 months (2-48 months). At the last follow-up, 2 patients were alive without recurrence of the tumor (the follow-up periods were 48 and 16 months). CONCLUSIONS: Neoadjuvant chemotherapy for AT/RTs might reduce both tumor size and vascularity, which enabled the maximal tumor resection. It may contribute to improve the prognosis of AT/RT through facilitating the tumor resection.

Meningioma with rhabdoid features combined with meningioangiomatosis in infancy: a novel combination.

Meningioangiomatosis is a rare histologically distinct abnormality that is occasionally associated with intracranial meningioma. The rhabdoid variant of meningioma is also uncommon and is classified as a World Health Organization Grade III tumour. We report a case of meningioangiomatosis in conjunction with a meningioma with prominent rhabdoid features, in an infant male who underwent complete surgical resection of the lesion. The patient has been followed up for 6 years with no disease recurrence. To our knowledge, this is the first report in the literature describing meningioangiomatosis combined with a meningioma with rhabdoid features.

Laser interstitial thermal therapy for pediatric atypical teratoid/rhabdoid tumor: case report.

Herein, the authors describe the successful use of laser interstitial thermal therapy (LITT) for management of metastatic craniospinal disease for biopsy-proven atypical teratoid/rhabdoid tumor in a 16-month-old boy presenting to their care. Specifically, LITT was administered to lesions of the right insula and left caudate. The patient tolerated 2 stages of LITT to the aforementioned lesions without complication and with evidence of radiographic improvement of lesions at the 2- and 6-month follow-up appointments. To the authors' knowledge, this represents the first such published report of LITT for management of atypical teratoid/rhabdoid tumor.

Atypical Teratoid/Rhabdoid Tumor of the Conus Medullaris.

INTRODUCTION: Atypical teratoid/rhabdoid tumor (AT/RT) is a rare tumor of the central nervous system, especially when involving the spinal column or spinal cord. CASE PRESENTATION: We present a case of a 5-year-old girl with progressive bilateral lower extremity pain found to have a discrete nodular lesion of the conus with mild heterogeneous enhancement. Surgical decompression and resection demonstrated a pathologic tumor consistent with AT/RT with loss of INI1 protein on immunohistochemistry. DISCUSSION AND CONCLUSION: AT/RT lesions of the conus medullaris are exceedingly rare and associated with extensive disease. We report a rare case of AT/RT with selective involvement of the conus medullaris, as well as describe the surgical, radiographic, and pathologic findings of this tumor.

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.

Dumbell atypical teratoid/rhabdoid tumour (AT/RT) of the cervical spine.

Spinal Atypical Teratoid/Rhabdoid Tumour (AT/RT) is a highly malignant tumour, and its prognosis is dismal especially for very young patients. In this article, we present the case of a teenage boy with AT/RT in the cervical spine and its multimodality management. A review of the literature on ATRT of the spine is also presented.

KBG syndrome patient due to 16q24.3 microdeletion presenting with a paratesticular rhabdoid tumor: Coincidence or cancer predisposition?

KBG syndrome is a rare autosomal dominant disorder caused by constitutive haploinsufficiency of the ankyrin repeat domain-containing protein 11 (ANKRD11) being the result of either loss-of-function gene variants or 16q24.3 microdeletions. The syndrome is characterized by a variable clinical phenotype comprising a distinct facial gestalt and variable neurological involvement. ANKRD11 is frequently affected by loss of heterozygosity in cancer. It influences the ligand-dependent transcriptional activation of nuclear receptors and tumor suppressive function of tumor protein TP53. ANKRD11 thus serves as a candidate tumor suppressor gene and it has been speculated that its haploinsufficiency may lead to an increased cancer risk in KBG syndrome patients. While no systematic data are available, we report here on the second KBG syndrome patient who developed a malignancy. At 17 years of age, the patient was diagnosed with a left-sided paratesticular extrarenal malignant rhabdoid tumor. Genetic investigations identified a somatic truncating gene variant in SMARCB1, which was not present in the germline, and a constitutional de novo 16q24.3 microdeletion leading to a loss of the entire ANKRD11 locus. Thus, KBG syndrome was diagnosed, which was in line with the clinical phenotype of the patient. At present, no specific measures for cancer surveillance can be recommended for KBG syndrome patients. However, a systematic follow-up and inclusion of KBG syndrome patients in registries (e.g., those currently established for cancer prone syndromes) will provide empiric data to support or deny an increased cancer risk in KBG syndrome in the future.