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

The Clinical and Surgical Characteristics of Parotid Tumors with Parapharyngeal Space Involvement-A Multicenter Experience of the Polish Salivary Network

Backgrounds/Objectives: Parotid gland tumors (PGTs) with parapharyngeal space (PPS) involvement have a specific clinical course and they can be a great challenge for surgeons, especially due to more difficult approaches and the risk of serious complications. The aim of this study is to present the characteristics of PGTs with PPS involvement. Methods: Retrospective, multicenter analysis of 1954 primary PGTs from 5 years (2017-2021) was performed. Comparative analysis was performed between groups with and without PPS involvement and included the following clinical and histopathological data: age, sex, place of residence, tumor size, FNAC result, percentage of malignant tumors, histological diagnosis, radicality of resection, and postoperative facial nerve (FN) dysfunction. Results: PPS involvement was found in 114 patients (5.83%). Secondary tumors affecting the deep lobe or the entire gland were predominant (46 and 60 cases, respectively). In a univariate analysis of tumors with and without PPS involvement, statistically significant differences were found in their size > 4 cm (12.97% vs. 37.72%), percentage of malignant tumors (7.12% vs. 17.55%), incidence of Warthin Tumors (WTs) (43.58% vs. 24.56%), percentage of R1 resection (5.53% vs. 12.50%), and rate of FN paresis (17.15% vs. 53.34%). Multivariate analysis showed that tumors with PPS involvement were statistically significantly characterized by larger size (tumors > 4 cm were 2.9 times more frequent), 2 times less frequent occurrence of WTs, and 1.6 times higher risk of FN paresis. Conclusion: PGTs with PPS involvement show certain clinical and histological differences and require more complex surgical accesses. Therefore, they cannot be treated as "ordinary" tumors occupying the deep lobe.

Evaluation of multiparametric MRI differentiating pleomorphic adenoma from schwannoma in parapharyngeal space

PURPOSE

This study aimed to investigate whether multiparametric magnetic resonance imaging (MRI) including dynamic contrast-enhanced (DCE) and diffusion weighted (DW) MRI can differentiate pleomorphic adenoma (PA) from schwannoma in the parapharyngeal space.

METHODS

Forty-six patients with pathologically proven PAs and 47 schwannomas in the parapharyngeal space were enrolled. All patients underwent conventional MRI, and DW-MRI and DCE-MRI were performed in 30 and 33 patients, respectively. Fisher's exact, Mann-Whitney-U tests and Independent samples t-test were used to compare variables between PAs and schwannomas. Multivariate logistic regression analysis was used to examine the diagnostic performance of MRI parameters.

RESULTS

The PAs usually show lobulation sign, posterior displacement of ICA and attached to the parotid gland deep leaf, while bird beak configuration, anterior displacement of ICA and involvement of foramen jugular were more commonly seen in the schwannomas(all p < 0.001). The washout rate of PAs was found to be higher than that of schwannomas (p = 0.035), whereas no significance was found in the other DCE-MRI parameters and in ADCs(p > 0.05). Using a combination of conventional MRI features including lobulation sign, bird beak configuration, direction of internal carotid artery(ICA) displacement and attached to the parotid gland in multivariate logistic regression analysis, sensitivity, specificity, and accuracy in differential diagnosis of PAs and schwannomas were 97.8%, 91.5% and 94.6%, respectively.

CONCLUSION

Conventional MRI can effectively differentiate PAs from schwannomas in the parapharyngeal space with a high diagnostic accuracy. The DCE-MRI and DWI have limited added diagnostic value to conventional MRI in the differential diagnosis.

Diagnostic and management challenge of concurrent tongue squamous cell carcinoma with an unknown parapharyngeal mass

There are very few case reports of the diagnosis and management of concurrent oral cavity and parapharyngeal space tumors. We present a case involving a 49-year-old female who presented with oral cavity squamous cell carcinoma confirmed by biopsy. Initial diagnostic workup revealed a concurrent parapharyngeal mass. Diagnostic studies and surgical therapy were tailored to account for both pathological entities. The patient was treated with a combination of surgery and adjuvant therapy. The surgical strategy was designed to address both lesions simultaneously. One year post-surgery, the patient had good response to therapy with no evidence of persistent or recurrent disease. This report discusses the outcome and treatment of a rare case of concurrent squamous cell carcinoma with a complicating parapharyngeal space tumor. It explores the diagnostic process, comprehensive workup, and the surgical management.

Primary Pathology of the Parapharyngeal Space

The radiologically defined parapharyngeal space is a distinct location on cross-sectional imaging and is often described based on its displacement or invasion by tumors or other pathologies in adjacent spaces; however, there are multiple primary pathologic entities of the parapharyngeal space, which are often forgotten. Recognizing that a lesion is arising from the parapharyngeal space is important in generating an accurate differential diagnosis that will guide management.

Parapharyngeal space carcinoma disguised as temporomandibular joint disorder: A clinical report

Parapharyngeal space neoplasms tend to have a considerable volume by the time of diagnosis because of their deep location in the neck and may have a relatively long progression before becoming symptomatic. Common presenting signs and symptoms of parapharyngeal space neoplasms include swelling in the neck, intraoral mass, dysphagia, dysphonia, heaviness in the ear, otalgia, and rarely, trismus. Some of these signs and symptoms could be mistaken for signs of temporomandibular disorder (TMD). This clinical report presents the incidental discovery of parapharyngeal space carcinoma initially presenting as TMD. A thorough clinical examination of the temporomandibular joints, supported by their magnetic resonance imaging, led to early detection of the neoplasm, thereby improving the patient's post-treatment survival probability.

Management of Parapharyngeal Space Tumors: Clinical Experience with a Large Sample and Review of the Literature

Parapharyngeal space (PPS) tumors are rare, and they account for 0.5-1.5% of all head and neck tumors. This study summarized the findings of large-sample clinical studies of PPS tumors and reported the clinical work-up and management of 177 cases of PPS tumors at our center. This retrospective study included patients treated for PPS tumors between 2005 and 2020 at our center. The basic characteristics, symptoms, surgical approach, complications, and recurrence rates were analyzed. A total of 99 male and 78 female patients, with a mean age of 48.3 ± 15.1 years, were enrolled in this study. The most common symptoms were external or intraoral masses (114 patients, 64%). Surgical management leveraging, a cervical approach, was used for 131 cases (74%). The tumors were benign for 92% (160 cases), with pleomorphic adenoma being the most common (88 cases, 50%). Surgical complications were reported for 31 cases (18%); facial and vocal cord paralyses were the most common. Three cases of recurrence were observed during the follow-up. PPS tumors are rare and present with atypical clinical manifestations. The current study, which involved cases in a large single center, demonstrates the importance of surgical interventions for PPS tumors. The use of endoscopic techniques has further expanded the scope of traditional surgical approaches and demonstrated its advantages in selected cases.

Surgical approaches for pleomorphic adenoma of the parapharyngeal space

OBJECTIVE

This study aimed to analyse the outcomes of surgery for pleomorphic adenoma of the parapharyngeal space in relation to the surgical approach.

METHOD

This was a single-centre retrospective data analysis conducted from January 2008 to December 2020 on all patients who underwent operation for pleomorphic adenoma originating from the parapharyngeal space.

RESULTS

Twenty-one patients with a mean age of 52.6 years were included. The transparotid-transcervical approach was the most common (52.4 per cent, n = 11) surgical approach, followed by transoral robotic surgery (28.6 per cent, n = 6) and conventional transoral surgery (19 per cent, n = 4). Post-operative complications included nine cases of transient partial facial nerve palsy and two cases of Frey's syndrome after the transparotid-transcervical approach and 2 cases of transient trismus and 1 pharyngeal wound dehiscence in the conventional transoral approach group. Complete macroscopic excision was always achieved, and no recurrence occurred during follow up.

CONCLUSION

These three approaches can provide adequate tumour visualisation, a high rate of clear excisional margins and an acceptable morbidity.