ABSTRACT
BACKGROUND: The parapharyngeal space (PPR) is poorly accessible to clinical investigation due to its complex anatomy. Neoplasms in this area are rare, become lately symptomatic and are diagnosed in advanced stages. Multiple entities can be differentiated though malignant mesenchymal tumors are uncommon. PATIENTS: We describe characteristic course of spindle cell soft tissue tumors in PPR based on 5 patients: 2 cases of synovial sarkoma (SyS), 2 cases of malignant peripheral nerve sheath tumor (MPNST) without neurofibromatosis, 1 case of Ektomesenchymoma (EM). RESULTS: Both patients with SyS showed under multimodal therapy with surgery, chemotherapy and radiotherapy a rapid tumor progression and early pulmonary metastatic disease. The 2 patients with MPNST were free of recurrence after tumor resection and in one case after adjuvant radiotherapy. The patient with EM showed no recurrence after surgery. CONCLUSION: Since malignant mesenchymal tumors of the PPR are unusual and also not have the typical behavior of metastatic epithelial neoplasms or malignant lymphoma, the diagnosis may be delayed. It is important to think in atypical lesions in PPR of the possibility of a soft tissue tumor and to arrange the necessary diagnostic steps. The imaging of choice of the PPR is the MRI, a staging adapted to the entity is necessary. The histological differentiation by immunohistochemistry and molecular genetics is complex, but is a vital to determine the optimal therapy. Diagnosis and treatment should take place in a specialized center.
