REVIEW ARTICLE: Paediatric nasopharyngeal rhabdomyosarcoma: A case series and literature review

A Rare Case of Pediatric Nasopharyngeal Rhabdomyosarcoma With Parameningeal Extension Presenting as a Thornwaldt Cyst

Rhabdomyosarcoma (RMS) is a common soft tissue malignancy of the pediatric age group, frequently involving the head and neck region; however, nasopharyngeal RMS is a rare entity. By virtue of its parameningeal involvement and nonspecific presentations, nasopharyngeal RMS has become a clinical challenge to diagnose. We present a case of an eight-year-old boy presenting with signs and symptoms of nasal obstruction who was initially being treated for tonsillitis. Recurrent episodes led to detailed examination and radiologic imaging, and a diagnosis of Thornwaldt cyst was made. For the relief of symptoms, a debulking surgery was performed followed by a biopsy which revealed the mass to be a nasopharyngeal RMS. Our case highlights the importance of including nasopharyngeal RMS into the differentials of midline nasal masses along with the role of biopsy for confirming its diagnosis as treatment modalities for it are strikingly different than the other more common group of conditions, i.e., benign nasal masses. While surgery is usually delayed in the latter group, it can be of prime importance while treating nasal RMS, along with chemotherapy and radiotherapy.

Top 10 Histological Mimics of Neuroendocrine Carcinoma You Should Not Miss in the Head and Neck

BACKGROUND

The spectrum of neuroendocrine neoplasia (NEN) of the head and neck region is wide-ranging and diverse, including a variety of diagnoses stretching from benign and low-malignant tumor forms to highly proliferative, poor prognosis neuroendocrine carcinoma (NEC). Moreover, there are several non-neuroendocrine differential diagnoses to keep in mind as well, displaying various degree of morphological and/or immunohistochemical overlap with bona fide neuroendocrine lesions.

METHODS

Review.

RESULTS

While the growth patterns may vary, well-differentiated NEN usually display a stippled "salt and pepper" chromatin, a granular cytoplasm, and unequivocal expression of neuroendocrine markers such as chromogranin A and synaptophysin. However, these features are often less pronounced in NEC, which may cause diagnostic confusion-not the least since several non-NEC head and neck tumors may exhibit morphological similarities and focal neuroendocrine differentiation.

CONCLUSION

As patients with NEC may require specific adjuvant treatment and follow-up, knowledge regarding differential diagnoses and potential pitfalls is therefore clinically relevant. In this review, the top ten morphological and/or immunohistochemical mimics of NEC are detailed in terms of histology, immunohistochemistry, and molecular genetics.

Nasal Embryonal Rhabdomyosarcoma in the Pediatric Population: Literature Review and Report of Midline Presentation

Background:

Congenital midline nasal masses are rare anomalies and are typically benign nasal dermoid sinus cysts (NDSCs). Rhabdomyosarcomas (RMSs) are even less common, and only a fraction affect sites like the external nose, nasal cavity, nasopharynx, and paranasal sinuses. We review the clinical presentation and treatment of nasal, nasopharyngeal, and paranasal RMSs and report the first documented midline presentation.

Methods:

We queried PubMed for articles with titles containing the terms rhabdomyosarcoma or sarcoma botryoides and nose, nasal, paranasal, sinonasal, nasopharynx, or nasopharyngeal. We then searched the references of each included article using the same parameters and continued this process iteratively until no new articles were found.

Results:

The paranasal sinuses were the most commonly affected site, followed by the nasopharynx, nasal cavity, and external nose. Two patients presented with involvement of the external nose, but each presented with involvement of the right ala rather than a midline mass. The rates of intracranial extension and/or skull base involvement were comparable to those of NDSCs. The alveolar subtype was most common, followed by the embryonal subtype.

Conclusions:

Most midline nasal masses are benign; however, we report the first documented presentation of an RMS as a midline nasal mass. Accordingly, RMS should be included in the differential diagnosis of midline nasal masses in the pediatric population. Surgery for midline nasal masses is sometimes delayed due to the risks of interfering with developing structures and early anesthesia. However, early surgical treatment should be considered given this new differential and its predilection for early metastasis.

Persistent pleural effusion in an infant with an unusual diagnosis: congenital alveolar rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a malignant form of neoplasm that originates from skeletal muscle. RMSs can exist anywhere in the human body but are more commonly detected in the neck region and extremities. The alveolar type is one of the subtypes of RMS that has a poor prognosis. Because the clinical manifestation of a tumour can be a painless mass, symptoms might be non-contributary to the diagnosis. Herein, a four-month-old girl was admitted to the emergency department with complaints of respiratory distress without a runny nose, cough, and fever. Recurrent effusions subsided with subsequent tube thoracostomy. Video-assisted thoracoscopic surgery (VATS) was performed to determine the aetiology of the recurrent effusion. The Tru-Cut biopsy obtained during VATS resulted in the diagnosis of alveolar rhabdomyosarcoma. Pleural effusion decreased, and the tube drainage was stopped rapidly after first vincristine, actinomycin-D, and cyclophosphamide chemotherapy cycle. Persistent and recurrent pleural effusions should alert physicians to rule out unusual diagnoses like that of our case.

Prosthetic rehabilitation for a patient treated for embryonal rhabdomyosarcoma

A female patient, now aged 17 years, was diagnosed with rhabdomyosarcoma (RMS) in the right pterygopalatine fossa when she was 3 years old. The RMS was successfully treated by excision, but the subsequent radiation and polychemotherapy resulted in the complete anesthesia of the distribution area of the right trigeminal nerve and loss of vision in the right eye. The patient also experienced pain in the mandibular joints and masticatory muscles. Panoramic radiographs displayed a multiple agenesia of the permanent teeth and underdeveloped apices. Treatment involved the fabrication of a complete maxillary denture. A removable device was fabricated to evaluate her response to an occlusal vertical dimension increase of 6 mm and provide a stable intercuspal position. After wearing the prosthesis for 6 months, the patient reported that she was completely free of symptoms.

Rhabdomyosarcoma mimicking as pleural effusion

Rhabdomyosarcoma (RMS), a malignant neoplasm of skeletal muscle origin, is the most common soft tissue sarcoma caused by infectious disease etiology, especially in nondeveloped countries. Despite being a relatively rare cancer, it accounts for approximately 40% of all recorded soft tissue sarcomas. Alveolar RMSs are seen to occur in children, while around 80% cases occur in the first three decades of life. We present here, a case of a 12-year-old child having alveolar RMS, presenting clinically and radiologically with pleural effusion.

PET/CT-guided treatment planning for paediatric cancer patients: a simulation study of proton and conventional photon therapy

OBJECTIVE

To investigate the impact of including fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography (PET) scanning in the planning of paediatric radiotherapy (RT).

METHODS

Target volumes were first delineated without and subsequently re-delineated with access to (18)F-FDG PET scan information, on duplicate CT sets. RT plans were generated for three-dimensional conformal photon RT (3DCRT) and intensity-modulated proton therapy (IMPT). The results were evaluated by comparison of target volumes, target dose coverage parameters, normal tissue complication probability (NTCP) and estimated risk of secondary cancer (SC).

RESULTS

Considerable deviations between CT- and PET/CT-guided target volumes were seen in 3 out of the 11 patients studied. However, averaging over the whole cohort, CT or PET/CT guidance introduced no significant difference in the shape or size of the target volumes, target dose coverage, irradiated volumes, estimated NTCP or SC risk, neither for IMPT nor 3DCRT.

CONCLUSION

Our results imply that the inclusion of PET/CT scans in the RT planning process could have considerable impact for individual patients. There were no general trends of increasing or decreasing irradiated volumes, suggesting that the long-term morbidity of RT in childhood would on average remain largely unaffected.

ADVANCES IN KNOWLEDGE

(18)F-FDG PET-based RT planning does not systematically change NTCP or SC risk for paediatric cancer patients compared with CT only. 3 out of 11 patients had a distinct change of target volumes when PET-guided planning was introduced. Dice and mismatch metrics are not sufficient to assess the consequences of target volume differences in the context of RT.

Models of biobanking and tissue preservation: RNA quality in archival samples in pathology laboratories and "in vivo biobanking" by tumor xenografts in nude mice-two models of quality assurance in pathology

Tissue banks represent essential resources and platforms for biomedical research serving basic, translational, and clinical research projects. In this article, we describe 2 models of biobanking and tissue preservation with different approaches and aims. Archive tissue biobanking is described here as a resource of residual pathology tissues for translational research, which represents the huge clinical heterogeneity. In this context, managing of tissues and RNA quality in archive tissue are discussed. The other model of tissue biobanking is referred to as xenograft tissue banking, which represents an alternative method for obtaining large amounts of tissue, over an indefinite period, in so far as the tumor can be transferred in vivo over generations, maintaining the histological and genetic particularities. A description of the method and examples of the application are given with particular emphasis on sarcomas (Ewing's sarcoma/primitive neuroectodermal sarcoma, synovial sarcomas, and rhabdomyosarcomas) and early stages of tumor angiogenesis in sarcomas.

Computed tomography and magnetic resonance imaging observations of rhabdomyosarcoma in the head and neck

Head and neck (HN) rhabdomyosarcoma (RMS) is an aggressive malignancy, which is rarely encountered and is commonly misdiagnosed as another type of tumor. The aim of the present study was to investigate the computed tomography (CT) and magnetic resonance imaging (MRI) features of HNRMS and analyze the correlations between the imaging observations and the pathological subtypes. A total of 10 HNRMS patients (three males and seven females; median age, 16 years) were reviewed retrospectively by only CT (n=1), only MRI (n=2), as well as CT and MRI (n=7). In addition, the clinical data, imaging observations and pathological results were recorded and analyzed. The origins of the 10 HNRMSs (eight embryonal and two alveolar subtypes) included the ethmoid sinus (n=4), maxillary sinus (n=1), orbit (n=3), nasopharynx (n=1) and frontotemporal subcutaneous area (n=1). On the CT and MRI images, the soft-tissue masses exhibited ill-defined borders (n=9), bony destruction (n=10), multi-cavity growth (n=7) and cervical lymph node metastasis (n=2), whereas calcification and hemorrhaging were not identified. On CT, eight of the HNRMSs appeared slightly hypodense (2/8) or isodense (6/8) with homogeneous enhancement (4/4). On T1-weighted images (WI), nine tumors exhibited isointensity (9/9) and on T2WI, six tumors demonstrated homogeneous hyperintensity with homogeneous enhancement on contrast-enhanced (CE)-T1WI. In addition, three embryonal RMSs, which originated from the ethmoid sinus, exhibited heterogeneous hyperintensity on T2WI and nodule-shaped enhancement patterns on CE-T1WI. The results of the present study indicated that MRI may accurately demonstrate the location and extent of HNRMS and that the imaging features of HNRMS may be similar to those of other tumors. However, a tumor exhibiting heterogeneous hyperintensity on T2WI and a nodule-shaped enhancement pattern on CE-T1WI in the ethmoid sinus may present specific MRI features, which clearly indicates the botryoid subtype of embryonal RMS.

Facial reconstruction surgery 10 years after treatment for hemangiopericytoma: planning considerations and clinical outcomes

This paper describes the surgical correction of ankylosis of the right temporomandibular joint and reconstruction of the middle and lower thirds of the right side of the face in a young man who had undergone treatment for hemangiopericytoma 10 years earlier, which led to serious functional, esthetic, and psychological problems and diminished his quality of life. The results of reconstruction surgery with alloplastic material (Medopor®) and surgical planning with fibrotic tissue due to radiation and the risk of osteoradionecrosis are discussed.

A low-grade myofibroblastic sarcoma in the abdominal cavity

Background

Rhabdomyosarcoma is the most common malignant tumor in the nasal and paranasal sinus area at childhood. Multimodal treatment for this disorder has severe side effects due to normal tissue damage. As a result of this treatment, facial growth retardation and oral abnormalities such as malformation of teeth and microstomia can cause esthetic and functional problems.

Case reports

Two cases are presented of patients with severe midfacial hypoplasia and reduced oral function as a result of treatment of rhabdomyosarcoma of the nasopharyngeal and nasal–tonsil region. With a combined surgical (osteotomy, distraction osteogenesis, implants) and prosthetic (implant-based overdenture) treatment, esthetics and function were improved.