Long-term Effects of Chemoradiation on an Embryonic Rhabdomyosarcoma of the Pterygopalatine Fossa

Introduction: As a malignant soft tissue tumour, rhabdomyosarcoma (RMS) develops from the cells of striated muscle. Among under 15-year-olds, the annual incidence is estimated at 1 in 224,000. The median diagnosis age is 5 years. Rhabdomyosarcoma can occur anywhere in the body, even in places where no striated muscle is present. The head and neck regions are affected in 40% of cases, most frequently the orbits and the paranasal sinuses. The currently applicable histological subclassification differentiates RMS between embryonic (variants: botryoid, spindle) and alveolar (variants: solid-alveolar and alveolar) varieties; the cause and origin are still largely unknown. The order and conduct of the individual types of therapy depend on the tumour and the patient's individual risk factors. Case report: In a now 15-year-old patient, rhabdomyosarcoma was diagnosed at the age of 3 years in the right pterygopalatine fossa with tendency to intracranial propagation, successfully treated by excision followed by radiotherapy (total dose: 45 Gy) and chemotherapy. As a result, there was complete anesthesia in the area supplied by the trigeminal nerve and the vision loss in the right eye. The skull growth of the irradiated side has been lower than on the unaffected side. In terms of positional relationship of both jaws, an Angle Class III could be ascertained. The patient also complained of the intraoral situation that had existing for years, because all the teeth had a mobility grade II-III, resulting in severe ingestion. In addition, pain occurred in the area of the temporomandibular joints and the muscles of mastication. In the panoramic radiograph, multiple agenesis of Dentes permanentes and rudimentary developed apices. The Capites of the mandible and processi coronoidei appeared degenerated and flattened. As part of the orthodontic consultation, a lateral cephalogram was made. As a potential therapeutic approach, the extraction of all teeth was introduced followed by implant insertion to allow the functional rehabilitation of the masticatory system. A prerequisite for implant-assisted therapy is a bimaxillary osteotomy, which the patient does not want to decide about at this time. Summary: Since rhabdomyosarcoma are localized in sensitive areas of the body, the treatment is demanding and multidisciplinary. The goal of treatment is to cure the young patients, while accepting possible minor side effects. The intention of this case report is to describe the problems after a combination therapy (surgical intervention, radiotherapy, and chemotherapy) in facial and oral structures at a now 15-year-old patient suffering from an embryonal rhabdomyosarcoma in the head and neck area. Keywords: rhabdomyosarcoma, radiation, long-term effects, oral health