Rhabdomyosarcoma of the head and neck in children

Rhabdomyosarcoma of the skull with EWSR1 fusion and ALK and cytokeratin expression: a case report

Rhabdomyosarcoma (RMS) comprises of heterogeneous group of neoplasms that occasionally express epithelial markers on immunohistochemistry (IHC). We herein report the case of a patient who developed RMS of the skull with EWSR1 fusion and anaplastic lymphoma kinase (ALK) and cytokeratin expression as cytomorphologic features. A 40-year-old man presented with a mass in his forehead. Surgical resection was performed, during which intraoperative frozen specimens were obtained. Squash cytology showed scattered or clustered spindle and epithelioid cells. IHC revealed that the resected tumor cells were positive for desmin, MyoD1, cytokeratin AE1/ AE3, and ALK. Although EWSR1 rearrangement was identified on fluorescence in situ hybridization, ALK, and TFCP2 rearrangement were not noted. Despite providing adjuvant chemoradiation therapy, the patient died of tumor progression 10 months after diagnosis. We emphasize that a subset of RMS can express cytokeratin and show characteristic histomorphology, implying the need for specific molecular examination.

Systemic sequelae and craniofacial development in survivors of pediatric rhabdomyosarcoma

INTRODUCTION

The aim of this study was to evaluate the systemic sequelae, as well as the dental and craniofacial development, of patients with rhabdomyosarcoma in relation to the treatment received and clinical-pathological variables.

MATERIALS AND METHODS

A retrospective cross-sectional study was performed. All individuals diagnosed with RMS between 1990 and 2022 were considered eligible. Cases who survived the primary tumor were included. Data were collected from medical records, and patients were called for clinical and radiographic examinations.

RESULTS

Thirty-eight patients were assessed, with a mean disease-free survival of 216.68 months (±84.99). The primary location of the tumor was mainly the head and neck region (57.9 %). All patients received chemotherapy, and 30 (78.9 %) also underwent radiotherapy. The most frequently observed sequela was sensory impairment, which was significantly associated with tumors in the head and neck (p < 0.05), as well as with the use of radiotherapy (p = 0.034). Root formation failure was observed in 60 % of cases, microdontia in 50 %, and delayed tooth eruption in 40 %. A convex profile was predominant (80 %), along with maxillary (50 %) and mandibular (80 %) retrusion and a skeletal class II diagnosis (60 %).

CONCLUSIONS

Late systemic, dental, and craniofacial developmental sequelae are observed in pediatric rhabdomyosarcoma survivors, especially in patients who underwent radiotherapy in the head and neck region. Younger individuals at the time of treatment are at greater risk of late sequelae.

Correlation of Genetic Polymorphism of CYP3A5 to Cyclophosphamide Efficacy and Toxicity in Rhabdomyosarcoma Pediatric Egyptian Cancer Patients

OBJECTIVES

Rhabdomyosarcoma (RMS) accounts for 50% of soft tissue sarcomas and 7% of pediatric malignancies. Cyclophosphamide (CPA) is the cornerstone of therapy and is a prodrug that is activated by the highly polymorphic drug-metabolizing enzyme CYP3A5. We aim to examine the possible CYP3A5 polymorphism association with CPA efficacy, survival outcomes, and toxicity in Egyptian pediatric RMS patients.

METHODS

The three non-functional SNPs, CYP3A5*3 rs776746 (C_26201809_30), CYP3A5*6 rs10264272 (C_30203950_10), and CYP3A5*7 rs41303343 (C_32287188_10) were genotyped by real-time PCR. We conducted a cohort retrospective study of 150 pediatric RMS patients treated with CPA-based first-line treatment to analyze the association between these genotypes and CPA efficacy/toxicities in RMS patients.

KEY FINDINGS

The frequency of having normal, intermediate, and poor metabolizers was 4.7%, 34%, and 61.3%, respectively. There was an association between these different phenotypes, genotypes, and CPA efficacy/toxicity. Hemorrhagic cystitis and pancytopenia were present in all patients, while nephrotoxicity incidence was 87.3%. There was a notable difference in the occurrence of hemorrhagic cystitis among CYP3A5 intermediate metabolizers *1/*3, *1/*6, and poor metabolizers *3/*3, *3/*6 with a significance level of p<0.05. Neither CYP3A5*7 polymorphism nor *6/*6 genotype was identified in our study.

CONCLUSION

Our results demonstrate that CYP3A5*3 (rs776746) and CYP3A5*6 (rs10264272) have a great association with CPA efficacy and toxicity in RMS patients.

Congenital Tooth Agenesis and Risk of Early-Onset Cancer

Importance

There is some evidence that tooth agenesis (congenital absence of 1 or more teeth) is associated with cancer risk, especially carcinomas of the colon and ovaries, but results of previous studies are conflicting, and associations have not yet been evaluated in a population-based setting.

Objective

To examine the association between tooth agenesis and specific cancer types before 40 years of age.

Design, Setting, and Participants

This population-based cohort study used linking data from nationwide registries in Denmark to assess all Danish live-born singletons born from January 1, 1977, to December 31, 2018, and followed up for up to 40 years. Data were analyzed from January through June 2023.

Exposure

Tooth agenesis as documented by the Danish Central Registry of Odontology (Danish municipal pediatric dental care) from January 1, 1988, to December 31, 2018, and from hospital encounters in the Danish National Patient Registry within the entire study period.

Main Outcome and Measures

The primary outcome was first cancer diagnosis before 40 years of age obtained from the Danish Cancer Registry. Associations between tooth agenesis and specific cancers were estimated by Cox proportional hazards regression as hazard ratios (HRs) with 95% CIs. Analyses were split into age groups: younger than 1 year, 1 to younger than 3 years, 3 to younger than 10 years, 10 to younger than 20 years, 20 to younger than 30 years, and 30 to younger than 40 years. Associations with nonsyndromic tooth agenesis were evaluated after exclusion of individuals with known syndromes.

Results

Among 2 501 715 included individuals (1 284 292 [51.3%] male), 70 288 (2.8%) had a diagnosis of tooth agenesis (mean [SD] age at diagnosis, 13.2 [4.1] years) and 26 308 (1.1%) had a diagnosis of early-onset cancer within the study period; 778 individuals had co-occurrence of tooth agenesis and cancer. Overall, tooth agenesis was positively associated with several cancer types, including neuroblastoma (age 1 to <3 years; HR, 4.20; 95% CI, 2.24-7.88), nephroblastoma (age 1 to <3 years; HR, 4.59; 95% CI, 2.37-8.91), hepatoblastoma (age 1 to <3 years; HR, 7.10; 95% CI, 2.70-18.68), osteosarcoma (age 10 to <20 years; HR, 2.19; 95% CI, 1.11-4.32), colorectal carcinomas (age 30 to <40 years; HR, 2.81; 95% CI, 1.38-5.71), and carcinomas of bladder (age 20 to <30 years; HR, 3.35; 95% CI, 1.35-8.30).

Conclusions and Relevance

This cohort study found associations between congenital tooth agenesis and several cancer types, from childhood to early adulthood. Further evaluation of these associations is needed to assess possible clinical implications.

What is this bump in my neck? Ultrasonographic evaluation of pediatric neck masses

Neck masses are common in pediatric patients, with benign etiologies such as congenital or inflammatory lesions accounting most of these masses. Anatomic location (most important), clinical history, and the appearance in ultrasonography (US) are helpful clues to narrow down differential diagnosis. Because of widespread availability, lack of ionizing radiation, and no need for sedation or contrast administration, US is the preferred initial modality for the evaluation. Further evaluation with cross-sectional imagings is needed for more extensive lesions with trans-spatial extension or suspicion of intrathoracic or retropharyngeal extension. This review will focus on US appearance and clinical presentation of masses of the neck in children, to enable radiologist to arrive at a reasonable differential diagnosis. We also briefly discuss more complex pathologies that need to be evaluated with cross-sectional modalities such as CT scan and magnetic resonance imaging.

Alveolar type of rhabdomyosarcoma of maxilla-A case report

Rhabdomyosarcoma (RMS) is the most common sarcoma among children and accounts for 20% of soft tissue sarcomas. In children, close to 50% of rhabdomyosarcomas arise in the head and neck. RMS of the oral cavity is rare and is seen in only 10-12% of all head and neck lesions and the involvement of the jaws is extremely rare. Histopathologically, the various types are pleomorphic type, botryoid type, spindle cell type, embryonal, and alveolar type of RMS. The alveolar variant accounts for almost 30% of all rhabdomyosarcomas and tends to arise in patients of the age group 10-25 years. We present a case of orofacial RMS in a young adult who was referred to our Institution for the management of an odontogenic lesion of the maxilla. The clinicopathological aspects and poor survival rate as a consequence of delayed diagnosis are discussed. We dentists may misdiagnose it as an odontogenic tumour due to its location in the oral and maxillofacial region. Careful clinical history and examination and investigations may help to narrow down the diagnosis. Expert opinion and referrals to oral pathologists and oncologists are essential to arrive at early diagnosis and to initiate the treatment.

Paediatric head and neck malignant neoplasms: A brazilian retrospective study

BACKGROUND

To assess the prevalence of oral and maxillofacial malignant neoplasias in children and adolescents diagnosed through biopsies sent to the Oral Pathology Laboratory at the University of Sao Paulo School of Dentistry.

MATERIAL AND METHODS

A retrospective analysis of anatomopathological reports on patients between 1 and 18 years old issued by the oral and maxillofacial pathology laboratory between 1997 and 2021 was performed for demographic data, lesion site, type of biopsy, diagnostic hypothesis and final diagnosis.

RESULTS

The laboratory issued 76,194 anatomopathological reports during this period, of which 10.77% were of children and adolescents. Of this total, only 32 biopsies (32/8.204; 0.39%) were neoplasias in children and adolescents. Sarcomas were the most prevalent malignant neoplasms (19/32; 59%), followed by carcinomas (7/32; 22%), lymphomas (5/32; 16%) and ganglioneuroblastomas (1/32; 3%). Of these 32 patients, the most affected individuals were aged between 4 and 11 years old (47%), 18 (56%) were male, and the mandible was the main anatomical site involved (28%). In 41% of the cases (13/32), the diagnostic hypothesis of the biopsied lesion was mistakenly considered benign and there was no diagnostic hypothesis in 18% of the cases.

CONCLUSIONS

Oral and maxillofacial malignant neoplasms in children and adolescents are uncommon and the accuracy of provisional diagnoses is low in these cases. Better knowledge on oral and maxillofacial malignant lesions in this population would help professionals to reduce the diagnostic time and consequently improve the patient's prognosis.

Rhabdomyosarcoma of the oral cavity in children aged 0-2 years: A scoping review

BACKGROUND

The aim of this study was to collect, synthesize, and analyze the clinic-demographic data of rhabdomyosarcoma affecting the oral cavity of young children.

METHODS

The clinical question was "What are the clinical characteristics of oral rhabdomyosarcoma in children aged zero to two years?" Two independent reviewers selected the studies, extracted data, and assessed the methodological quality through the Joanna Briggs Institute Checklist. Descriptive statistics were performed in SPSS. (protocol: osf.io/b9hvy).

RESULTS

Thirty case reports with 41 patients were included (22 males; mean age at diagnosis: 15 months). All studies had some methodological limitations, mainly due to the lack of clarity for a final judgment. More than 70% of the cases affected the tongue or lips. Tumors had a fast growth (mean 2.5 months), usually with red coloration, and variable shape and consistency. Embryonal (63.41%) and alveolar (29.27%) were the most common histological subtypes. Treatment was quite variable but usually included surgery. Most patients (53.66%) were alive without disease at follow-up.

CONCLUSION

Oral rhabdomyosarcoma is rare in children aged 0-2 years without a marked gender predilection. The tumor presents as a fast and infiltrative growth leading to local and/or systemic symptoms, and a favorable prognosis for most patients.

International Society of Paediatric Surgical Oncology (IPSO) Surgical Practice Guidelines

Most children with tumors will require one or more surgical interventions as part of the care and treatment, including making a diagnosis, obtaining adequate venous access, performing a surgical resection for solid tumors (with staging and reconstruction), performing procedures for cancer prevention and its late effects, and managing complications of treatment; all with the goal of improving survival and quality of life. It is important for surgeons to adhere to sound pediatric surgical oncology principles, as they are closely associated with improved local control and survival. Unfortunately, there is a significant disparity in survival rates in low and middle income countries, when compared to those from high income countries. The International Society of Paediatric Surgical Oncology (IPSO) is the leading organization that deals with pediatric surgical oncology worldwide. This organization allows experts in the field from around the globe to gather and address the surgical needs of children with cancer. IPSO has been invited to contribute surgical guidance as part of the World Health Organization Initiative for Childhood Cancer. One of our goals is to provide surgical guidance for different scenarios, including those experienced in High- (HICs) and Low- and Middle-Income Countries (LMICs). With this in mind, the following guidelines have been developed by authors from both HICs and LMICs. These have been further validated by experts with the aim of providing evidence-based information for surgeons who care for children with cancer. We hope that this initiative will benefit children worldwide in the best way possible. Simone Abib, IPSO President Justin T Gerstle, IPSO Education Committee Chair Chan Hon Chui, IPSO Secretary.

Radiation Therapy in the Treatment of Head and Neck Rhabdomyosarcoma

The use of radiation therapy is an important part of multimodality treatment for rhabdomyosarcoma. The specific doses, treatment volumes, and techniques used in radiation therapy can vary dramatically based upon a number of factors including location, tumor size, and molecular characteristics, resulting in complex decisions in treatment planning. This article reviews the principles of evaluation and management for head and neck rhabdomyosarcoma including a summary of the historical studies upon which current management is based.

When a stuffy nose won't go away: Rhabdomyosarcoma masquerading as adenoiditis

Embryonal Rhabdomyosarcoma is a malignant mesenchymal proliferation of immature skeletal muscle and may arise in children in the orbit, middle ear, nasal cavity, paranasal sinuses, or nasopharynx. Clinical diagnosis may be difficult in a subset of patients who have no significant deformities or irregularities upon visual inspection of the oropharynx. Rhabdomyosarcoma in this setting may be mistaken for a more common underlying etiology such as an upper respiratory infection. We report a case of a 7-year-old male with embryonal variant rhabdomyosarcoma previously misdiagnosed by 3 different physicians to be adenoiditis based on clinical exam and laryngoscopy. This case highlights the capacity for rhabdomyosarcoma to mimic commonly encountered adenoiditis. It also serves as a reminder to maintain a high level of diagnostic vigilance and clinical suspicion of noninfectious etiologies when symptoms persist and are refractory to standard treatment.

Pediatric head and neck rhabdomyosarcoma: An analysis of treatment and survival in the United States (1975-2016)

INTRODUCTION

Rhabdomyosarcoma (RMS) is the most common soft tissue head and neck sarcoma in children. Stringent analysis of survival data is imperative to optimize treatment.

METHODS

The National Cancer Database (NCDB, 2004-2016) and the Surveillance, Epidemiology, and End Results Program (SEER, 1975-2016) were queried for patients ages 0-19 with RMS of the head and neck. Survival trends were analyzed using univariable logistic regression and Chi-square pairwise comparisons. Survival by treatment was analyzed using log-rank tests, Kaplan Meier, and multivariable Cox-proportional hazards regression.

RESULTS

1147 (63.3% age <10 years, 54.3% male) and 459 (71.4% age <10 years, 53.6% male) patients were identified in NCDB and SEER, respectively. In NCDB, embryonal (n = 625, 54.5%) and alveolar (n = 300, 26.2%) were the most common histology and nonparameningeal/non-orbital (n = 634, 55.3%), followed by parameningeal (n = 303, 26.4%) and orbital (n = 210, 18.3%) the most common location. Five-year overall survival (OS) was 70.3% with lower mortality risk for embryonal histology (adjusted HR [aHR] = 0.69, p = 0.0038). Orbital tumors had greatest survival (5-year OS = 92.4%) of all sites, and their mortality risk was higher with chemotherapy and radiation compared to surgery and radiation (aHR = 6.27, p = 0.0302). SEER analysis showed average increased survival by 4% per year (p < 0.0001), but no significant 5-year OS difference when comparing 1976-1980 and 2006-2010 (p = 0.0843).

CONCLUSIONS

Major prognostic factors for survival in childhood RMS of the head and neck were embryonal histology, orbital site, extent of disease, and use of SRT for orbital tumors. Larger population studies are required to demonstrate survival differences between treatment modalities for other sites.

Prognostic Factors in Patients with Rhabdomyosarcoma Using Competing-Risks Analysis: A Study of Cases in the SEER Database

Background

Rhabdomyosarcoma (RMS) is a rare malignant soft-tissue sarcoma characterized by a poor outcome and unclear prognostic factors. This study applied a competing-risks analysis using data from the Surveillance, Epidemiology, and End Results (SEER) database to RMS patients, with the aim of identifying more accurate prognostic factors.

Methods

Data of all patients with RMS during 1986–2015 were extracted from the SEER database. We used the competing-risks approach to calculate the cumulative incidence function (CIF) for death due to rhabdomyosarcoma (DTR) and death from other causes (DOC) at each time point. The Fine–Gray subdistribution proportional-hazards model was then applied in univariate and multivariate analyses to determine how the CIF differs between groups and to identify independent prognostic factors. The potential prognostic factors were analyzed using the competing-risks analysis methods in SAS and R statistical software.

Results

This study included 3399 patients with RMS. The 5-year cumulative incidence rates of DTR and DOC after an RMS diagnosis were 39.9% and 8.7%, respectively. The multivariate analysis indicated that age, year of diagnosis, race, primary site, historic stage, tumor size, histology subtype, and surgery status significantly affected the probability of DTR and were independent prognostic factors in patients with RMS. A nomogram model was constructed based on multivariate models for DTR and DOC. The performances of the two models were validated by calibration and discrimination, with C-index values of 0.758 and 0.670, respectively.

Conclusions

A prognostic nomogram model based on the competing-risks model has been established for predicting the probability of death in patients with RMS. This validated prognostic model may be useful when choosing treatment strategies and for predicting survival.

Incidental Hamartoma in an elderly patient: a case report

Background

Neuromuscular hamartoma is a very rare tumor; with only five cases reported in the orbit. It often occurs in infants and young children and involves large peripheral nerves, but there has been only few reports of occurrence in the orbit and adults.

Case presentation

This paper describes a 70-year-old man with an incidental orbital mass detected by an imaging test and who later developed associated symptoms. The mass was diagnosed as neuromuscular hamartoma. Superior rectus muscle recession and inferior rectus muscle resection were performed in the right eye for hypertropia secondary to postoperative inferior rectus muscle palsy. Hypertropia in the right eye and diplopia improved after surgery, and regular follow-up is underway.

Conclusion

This is the first case of an incidentally detected orbital mass diagnosed by histologic examination as a neuromuscular hamartoma in an older patient whose proptosis progressed after a long period of inactivity.

The expanded endonasal approach in pediatric skull base surgery: A review

OBJECTIVE

Surgery of the pediatric skull base has multiple unique challenges and has seen recent rapid advances. The objective of this review is to assess key issues in pediatric skull base surgery (SBS), including anatomic limitations, surgical approaches, reconstruction techniques, postoperative care, complications, and outcomes.

DATA SOURCES

PubMed literature review.

REVIEW METHODS

A review of the literature was conducted to assess the challenges, recent advances, and reported outcomes in pediatric SBS.

RESULTS

The pediatric skull base presents multiple anatomic challenges, including variable patterns of pneumatization, narrow piriform aperture width, and narrow intercarotid distance at the level of the cavernous sinus but not the superior clivus. These issues may be particularly challenging in patients less than 2 years of age. Endoscopic endonasal approaches in the sagittal and coronal plane have been applied to the pediatric skull base while open approaches may still be necessary in the setting of extensive intracranial or orbital disease, as well as disease lateral to critical neurovascular structures. While the nasoseptal flap was initially called into question for pediatric cases, it has been shown through multiple reports to be a feasible and robust reconstructive option. Complications and outcomes often depend upon the pathology. In children, response to noxious stimuli, ability to avoid Valsalva, and adherence to nasal precautions is variable. The use of lumbar drains is more common in pediatric than adult patients.

CONCLUSION

While the pediatric skull base presents unique challenges, outcomes data support that endoscopic endonasal approaches are a pertinent surgical technique in appropriately selected patients.

LEVEL OF EVIDENCE

3a.

Clinical Utility of In Situ Hybridization Assays in Head and Neck Neoplasms

Head and neck pathology present a unique set of challenges including the morphological diversity of the neoplasms and presentation of metastases of unknown primary origin. The detection of human papillomavirus and Epstein-Barr virus associated with squamous cell carcinoma and newer entities like HPV-related carcinoma with adenoid cystic like features have critical prognostic and management implications. In salivary gland neoplasms, differential diagnoses can be broad and include non-neoplastic conditions as well as benign and malignant neoplasms. The detection of specific gene rearrangements can be immensely helpful in reaching the diagnosis in pleomorphic adenoma, mucoepidermoid carcinoma, secretory carcinoma, hyalinizing clear cell carcinoma and adenoid cystic carcinoma. Furthermore, molecular techniques are essential in diagnosis of small round blue cell neoplasms and spindle cell neoplasms including Ewing sarcoma, rhabdomyosarcoma, synovial sarcoma, biphenotypic sinonasal sarcoma, dermatofibrosarcoma protuberans, nodular fasciitis and inflammatory myofibroblastic tumor. The detection of genetic rearrangements is also important in lymphomas particularly in identifying 'double-hit' and 'triple-hit' lymphomas in diffuse large B cell lymphoma. This article reviews the use of in situ hybridization in the diagnosis of these neoplasms.

Prognostic factors for postoperative survival among patients with rhabdomyosarcoma of the limbs

BACKGROUND

Rhabdomyosarcoma (RMS) is a rare malignant soft tissue sarcoma with a poor outcome and unclear prognostic factors. The purpose of this study was to analyze the prognostic postoperative survival factors among patients with RMS of the limbs.

METHODS

Postoperative data on patients with RMS of the limbs from 1983 to 2013 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database of the US National Cancer Institute. Both overall survival (OS) and cancer-specific survival (CSS) were assessed using the Kaplan-Meier method (to obtain OS and CSS curves) and a Cox proportional hazards regression model.

RESULTS

In total, 385 cases were obtained from the SEER database. The 5- and 10-year OS rates of the entire group were 51.5% and 42.2%, respectively. The 5- and 10-year CSS rates were 56.7% and 50.7%, respectively. Univariate analysis revealed that age, location, tumor stage, tumor size, and radiation therapy (RT) were associated with OS. Age, tumor stage, tumor size, and RT were associated with CSS. Age, tumor stage, tumor size, and RT were also independent predictors of both OS and CSS.

CONCLUSION

Young age, no metastasis at presentation, smaller tumor size, and RT are favorable factors for prolonging survival among patients with RMS of the limbs after surgery.

Rhabdomyosarcoma of the Head and Neck: A Multimodal Approach

Head and neck rhabdomyosarcoma (HNRMS) is a uniquely challenging site to treat given the young patient age and critical anatomy of the head and neck region. We review the characteristics, management, and future directions in the treatment of HNRMS. Most patients who present with HNRMS have unresectable disease due to functional and/or cosmetic constraints. However, surgical resection and brachytherapy serve a critical role in select patients. The treatment paradigm for the majority of patients with HNRMS consists of definitive chemotherapy and radiation therapy. As the incidence of late toxicities increases with improved survival, modern efforts must focus on ways to decrease long-term morbidity. We recommend a multimodal approach emphasizing the preservation of form and function for the treatment of HNRMS.

Surgical Interventions for Advanced Parameningeal Rhabdomyosarcoma of Children and Adolescents

Owing to its rarity, rhabdomyosarcoma of the head and neck (HNRMS) has seldom been discussed in the literature. As most of the data is based only on the retrospective experiences of tertiary healthcare centers, there are difficulties in formulating a standard treatment protocol. Moreover, the disease is poorly understood at its pathological, genetic, and molecular levels. For instance, 20% of all histological assessment is inaccurate; even an experienced pathologist can confuse rhabdomyosarcoma (RMS) with neuroblastoma, Ewing’s sarcoma, and lymphoma. RMS can occur sporadically or in association with genetic syndromes associated with predisposition to other cancers such as Li-Fraumeni syndrome and neurofibromatosis type 1 (von Recklinghausen disease). Such associations have a potential role in future gene therapies but are yet to be fully confirmed. Currently, chemotherapies are ineffective in advanced or metastatic disease and there is lack of targeted chemotherapy or biological therapy against RMS. Also, reported uses of chemotherapy for RMS have not produced reasonable responses in all cases. Despite numerous molecular and biological studies during the past three decades, the chemotherapeutic regimen remains unchanged. This vincristine, actinomycin, cyclophosphamide (VAC) regime, described in Kilman, et al. (1973) and Koop, et al. (1963), has achieved limited success in controlling the progression of RMS. Thus, the pathogenesis of RMS remains poorly understood despite extensive modern trials and more than 30 years of studies exploring the chemotherapeutic options. This suggests a need to explore surgical options for managing the disease. Surgery is the single most critical therapy for pediatric HNRMS. However, very few studies have explored the surgical management of pediatric HNRMS and there is no standard surgical protocol. The aim of this review is to explore and address such issues in the hope of maximizing the number of options available for young patients with HNRMS.

Oral rhabdomyosarcoma in an adult male: A rare case report

Rhabdomyosarcoma is a malignant neoplasm of mesenchymal cells, showing varying degrees of striated muscle cell differentiation. It predominantly occurs in children while rarely found in adults and involvement of the oral cavity accounts for only 10%-12% of all head-and-neck cases. Herewith, we present a rare case of spindle cell rhabdomyosarcoma in a 52-year old male, involving the mandibular gingiva, and describe the clinical, radiological, histopathological and immunohistochemical findings.

Head and neck rhabdomyosarcoma in children: a 20-year retrospective study at a tertiary referral center

OBJECTIVE

The purpose of this study was to assess rhabdomyosarcomas (RMS) of the head and neck in pediatric patients with regard to clinical presentation, treatment, and survival.

METHODS

Data were retrospectively obtained from patient charts with regard to RMS of the head and neck diagnosed between 1996 and 2016 at a tertiary referral center. Clinical course, treatment modalities, and side effects were analyzed. Survival analysis was carried out using the Kaplan-Meier method.

RESULTS

Twenty-eight patients (17 male, 11 female) with a mean age at diagnosis of 6.8 ± 5.0 years have been included. Fourteen patients (50%) presented with painless swelling in the head and neck region and nine patients (32.1%) presented with cranial nerve deficit at initial diagnosis. The location of the majority of rhabdomyosarcomas was orbital (N = 9; 32.1%), followed by parapharyngeal (n = 4; 14.2%) and sinonasal (n = 3; 10.7%). All patients (n = 28; 100%) received polychemotherapy, additional adjuvant radiation therapy was carried out in 24 patients (85.7%), and surgery was performed in 12 cases (42.9%). The 5-year overall survival was 91.3%, and median progression-free survival was 46 ± 67.4 months. Common side effects resulting from chemotherapy and radiation therapy included neutropenia, mucositis, nausea and vomiting, and radiodermatitis, long-term side effects included microsomia and facial mutilation.

CONCLUSION

Multimodality treatment of rhabdomyosarcomas of the head and neck in pediatric patients may lead to a 5-year overall survival of up to 91.3%.

Management of pediatric head and neck rhabdomyosarcoma: A case-series of 36 patients

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in the pediatric population. In 35% of cases, RMS develops in the head and neck (H&N) region, and only combined therapy is recognized as a curative treatment. However, recent advances in skull base and reconstructive surgery, along with microsurgery and endoscopic surgery, have strengthened the role of surgery as an important part of RMS treatment. In the present study, 36 pediatric RMS cases (24 males and 12 females) were analyzed after surgical treatment. The average age at diagnosis was 7 years. In total, 67% of tumors were localized in the parameningeal region. Alveolar RMS was the most common histopathological type. A total of 16 patients were treated due to disease recurrence or a previous non-radical surgical procedure, while 19 cases had inductive chemotherapy and/or radiotherapy preceding surgical treatment due to locally advanced disease. In 1 case, only diagnostic biopsy was performed. It is recommended that the management of H&N RMS is interdisciplinary from the beginning. Extensive surgical dissection in the H&N region for RMS may result in severe cosmetic defects and functional impairment; thus, these risks should be considered during treatment planning, and the surgical approach should be based on the individual characteristics of each patient.

Diagnostic imaging of benign and malignant neck masses in children-a pictorial review

Neck masses are frequently encountered in pediatric medicine, and can present a diagnostic dilemma for the clinicians involved. There are several means by which neck masses in children can be subdivided, for example by age at presentation, anatomical location including compartments and fascia of the neck, their classical appearance when imaged, or by etiology. When imaging children the clinicians must be mindful of radiation exposure and as such ultrasound (US) is often attempted first. Cross sectional imaging can be helpful for problem solving with CT being particularly useful for assessing the patient in more acute scenarios, for example when there is airway compromise. Nuclear medicine scintigraphy has a role in specific circumstances and can aid in staging in the presence of malignancy. If required, additional acquisition by means of magnetic resonance imaging (MRI) and computed tomography (CT) can be considered. This pictorial review describe the diagnostic imaging of (I) congenital and Developmental Pathologies, including thyroglossal duct cyst, branchial cleft cyst, cystic hygroma, dermoid cyst, thymic cyst and ectopic thymus; (II) neoplastic lesions, including hemangiomas and vascular malformations, pilomatrixoma, neurofibroma, neuroblastoma, rhabdomyosarcoma, papillary thyroid cancer, lymphoma & leukemia; (III) neck masses of Infective causes, including lymphadenitis, retropharyngeal and peritonsilar abscess, salivary gland inflammation; and (IV) other miscellaneous lesions, including ranula, sternocleidomastoid fibromatosis coli, and goiter. Neck masses are common in the pediatric population with a broad and varied differential; malignant etiologies are less frequently encountered when compared with adults but an awareness of its potential is important when reviewing imaging.

CYP2B6rs2279343 Is Associated with Improved Survival of Pediatric Rhabdomyosarcoma Treated with Cyclophosphamide

Background

Rhabdomyosarcoma (RMS) is a small round blue cell malignant tumor, representing 7% of childhood malignancies, and over 50% of all soft tissue sarcomas. Cyclophosphamide (CPA) is a prodrug and is the mainstay of RMS treatment. CYP2B6 is a highly polymorphic drug metabolizing enzyme involved in CPA bioactivation. The influence of CYP2B6 single nucleotide polymorphisms (SNPs) on the survival of RMS is still unknown.

Methods

We genotyped CYP2B6SNPs rs2279343, rs3745274, and rs3211371 by restriction fragment polymorphism (RFLP) after PCR amplification in a cohort of 73 pediatric RMS patients treated with CPA-based first line treatment. We then analyzed the association between those genotypes and survival outcome of RMS.

Results

The frequencies of CYP2B6 rs2279343, rs3745274, and rs3211371 were 63%, 45.2%, and 5.5%, respectively. There was no association between rs3745274, rs3211371 genotypes and survival outcomes of RMS. However, the carriers of at least one mutant allele CYP2B6rs2279343 had significantly longer event-free survival (p-value = 0.03).

Conclusion

Our results demonstrated that CYP2B6 rs2279343 may predict EFS in RMS patients and warrants future studies to clarify the pharmacogenetics of CPA in pediatrics. If validated, integration of genetic factors with clinical and molecular characteristics could be used for a composite algorithm to better stratify risk prior to treatment.

A Patient-Derived Xenograft Model of Parameningeal Embryonal Rhabdomyosarcoma for Preclinical Studies

Embryonal rhabdomyosarcoma (eRMS) is one of the most common soft tissue sarcomas in children and adolescents. Parameningeal eRMS is a variant that is often more difficult to treat than eRMS occurring at other sites. A 14-year-old female with persistent headaches and rapid weight loss was diagnosed with parameningeal eRMS. She progressed and died despite chemotherapy with vincristine, actinomycin-D, and cyclophosphamide plus 50.4 Gy radiation therapy to the primary tumor site. Tumor specimens were acquired by rapid autopsy and tumor tissue was transplanted into immunodeficient mice to create a patient-derived xenograft (PDX) animal model. As autopsy specimens had an ALK R1181C mutation, PDX tumor bearing animals were treated with the pan-kinase inhibitor lestaurtinib but demonstrated no decrease in tumor growth, suggesting that single agent kinase inhibitor therapy may be insufficient in similar cases. This unique parameningeal eRMS PDX model is publicly available for preclinical study.