Clinicopathologic study of parapharyngeal tumors

Primary neoplasms of the parapharyngeal space: diagnostic and therapeutic pearls and pitfalls

PURPOSE

Parapharyngeal space neoplasms (PSNs) are rare tumors of the head and neck region. In this study, we report our institutional experience with PSNs over a 27-years period.

METHODS

Patients treated between 1992 and 2018 were identified through our tumor board database. Data concerning demographics, clinical presentation, disease features, treatment, complications and follow-up were obtained retrospectively.

RESULTS

In total, 48 patients were identified. Most patients had benign tumors (67.5%), with pleomorphic adenoma and schwannoma being the most frequent entities. Malignant tumors represented the remaining 32.5% of neoplasms. Concerning tissue of origin, 67.5% of neoplasms originated from salivary glands and 17.5% were neurogenic. The vast majority of PSNs required open surgical approaches (77%). The most frequent reversible and irreversible complications included paralysis of facial, vagal, and hypoglossal nerves (transient 62.5%, permanent 31.3%). Tumor recurrences occurred in 16.7% of our patients.

CONCLUSION

Neoplasms of the parapharyngeal space (PPS) are rare. In our series, consistent with the literature, most patients had benign tumors. Fine-needle aspiration cytology (FNAC) and/or transoral biopsy in selected cases combined with radiographic imaging are helpful to plan the optimal approach (open/transoral) and extent of primary surgery. Close follow-up in malignant neoplasms is crucial to assess recurrence early. We present one of the largest recent studies on PPS tumors treated in a center. Given the low incidence of these tumors, our results contribute to the existing sparse evidence regarding the management and outcome of such tumors.

Myoepithelial cell-rich pleormorphic adenoma of minor salivary gland of parapharyngeal space

Parapharyngeal space tumors are rare and constitute only 0.5–1.0% of head and neck tumors. Minor salivary gland tumor is still rare in parapharyngeal space. We are reporting a case of pleomorphic adenoma of minor salivary gland of parapharyngeal space. A 42-year-old female presented with a history of mass in the oropharynx for 3 years. She presented with “hot potato voice” and dysphagia. CECT and MRI were done, showing large parapharyngeal space tumor. FNAC was suspicious for tumor of nerve cell origin. Tumor was excised using “paramedian mandibulotomy with mandibular swing approach”. Histopathological examination was inconclusive, suggesting possibility of extraskeletal myxoid chondrosarcoma, solitary fibrous tumor, neurogenic tumor. On immunohistochemistry, tumor was positive for cytokeratin, EMA (dim), S-100, and P 63 and negative for SMA thus proving the case as myoepithelial cell-rich pleomorphic adenoma.