# Unusual Presentation of Juvenile Rhabdomyosarcoma in the Temporomandibular Area: A Case Report
## 3 Discussion  
RMS is an aggressive malignancy composed of neoplastic mesenchymal cells, with varying degrees of striated muscle differentiation. It is characterized by rapid growth through bone erosion. The RMS of the head and neck region is usually associated with facial swelling and symptoms such as sore throat, nasal airway obstruction and pain. These non-specific symptoms are responsible for a diagnostic delay that is crucial for the prognosis [14]. [PERSON] and coworkers [15] reported a mean time interval of 21 weeks from symptom onset to diagnosis; this is a very important aspect since the prognosis is directly related to the stage of the disease as well as to the anatomical location and histological aspect. Concerning the case described in this report, it took four months to reach a correct diagnosis after the onset of symptoms. Some confounding factors, such as the temporal association between the onset of pain and the trauma and the presence of limited mandibular function, caused a delay of the appropriate diagnostic process by clinicians, who were first oriented toward a TMD. Furthermore, despite the increase in pain and dysfunction, no facial asymmetry or swelling occurred over time, since the tumor involved the right TMJ area and grew intracranially, causing compression-related symptoms. Similar clinical aspects can be found in the presence of acoustic neuromoma, which, however, is frequently associated with monolateral deafness, vertigo and tinnitus, which were not present in the patient of the present paper. Another pathology that must be excluded is the trigeminal neuralgia (TN), which manifests itself as a sudden pain, usually unilateral, severe, brief, stabbing, recurrent and localized in the area of distribution of one or more branches of the fifth cranial nerve: these characteristics are very similar to the signs and symptoms of our patient. However, TN is a rare disease in children [16], and other pathologies commonly affecting the head and neck district in young subjects, such as fibrosarcoma, leiomyosarcoma, neurofibrosarcoma, RMS [17], lymphatic-venous malformations [18] (that can grow and become clinically apparent only after the onset of respiratory infections), must be ruled out by radiological and histological examination [19]. In this case report, a more accurate anamnesis and the careful evaluation of the peculiar pain characteristics led to further investigation. The patient referred to discomfort for a year before receiving the correct diagnosis: occasional, intermittent or mild symptoms may be underestimated or misdiagnosed, but it is essential to properly evaluate the presence of pain in children as in adult subjects, even if not associated with functional limitation. In addition to the clinical aspects, the imaging plays a fundamental role in the diagnostic process of RMS. A joint task force of the Children's Oncology Group and the Society for Pediatric Radiology investigated the current landscape of medical imaging for children with cancer, providing an overview of the risks and benefits associated with commonly used modalities. The authors underline that MRI is superior to CT in evaluating regions involving predominantly soft tissue and is preferred for imaging of the head and  
Figure 3: Immunohistochemistry: (**a**) diffuser staining of _desmin;_ (**b**) patchy positivity for _myogenin_. (Original magnification 400\(\times\)). neck [20]. [PERSON] and coworkers [19] reported a similar case of RMS in the intratemporal fossa showing how CT scans failed to detect a mass that MRI delineated well. It appears that tumors involving sites such as the intratemporal fossa and TMJ may be difficult to evaluate by CT, due to severe interference from bone artifact and limited section planes. Although CT is considered the best method for evaluating bone erosions or fractures, MRI can also show these lesions. Furthermore, artifacts caused by metallic dental restorations sometimes produce serious diagnostic problems in CT examinations of malignant tumors of the oral and maxillofacial region.