Science et thérapie du cancer

Role of 18F-FDG PET Scan in Parapharyngeal Space Tumors: Report of a Rare Case and Review of the Literature

Abstract

Sahel OA, Biyi A, Ennouali H, Benameur Y, Bouyallaoui H, and Doudouh A

Background: Tumors of the parapharyngeal space (PPS) are rare and account for only 0.5% of head and neck neoplasms. Approximately 80% of these tumors are benign lesions, yet they represent a formidable diagnostic and treatment challenge. They are difficult to diagnose because they have few symptoms, therefore, CT and MRI are essential to delineate the tumor extent, intracranial involvement and relationship to the adjacent vital structures. Case presentation: We report the case of a 36-year-old male who presented with the sudden onset of a pharyngeal cavity mass. CT head and neck scan and MRI showed a left paraphayngeal mass occupying the prestyloid parapharyngeal space extending to poststyloid. Transorally biopsy revealed a well differenced squamous cell carcinoma. A FDG PET/CT was performed and revealed outside the known tumor, vertebral metastasis of the cervical and thoracic spine, a right collarbone metastasis and pulmonary nodules. It was decided to manage this metastatic squamous cell carcinoma with chemotherapy. Conclusion: Parapharyngeal squamous cell carcinomas are extremely rare. Imaging helps in planning the surgical procedure. Radionuclide imaging is complimentary to radiological imaging and provides specific information about the tumor’s functional and molecular characteristics. This case of squamous cell carcinoma presents several unusual features: the scarcity of squamous cell carcinoma in the paraphayngeal space and faraway metastasis in this type of tumor. Moreover the role of FDG PET/CT have been exceptionally described in the literature.