Parapharyngeal space tumours: an 18 year review

Review of retropharyngeal and parapharyngeal nodal metastasis of papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. In rare instances, PTC has metastasized to the retropharyngeal and parapharyngeal nodes. This is hypothesized to occur due to an aberrant lymphatic channel or via retrograde lymphatic flow following previous neck dissection.

METHODS

A literature search was conducted with keywords "parapharyngeal," "retropharyngeal," and "papillary thyroid carcinoma."

RESULTS

46 articles were identified for a total of 135 cases. The most common presenting symptom was lymphadenopathy followed by pharyngeal mass and dyspnea. 38.03 % of patients were asymptomatic. Of cases including initial treatment history, 94.44 % had a history of neck dissection. The transcervical approach was the most utilized to resect the tumors, although in recent years trans-oral robotic surgery (TORS) has also been used.

CONCLUSION

PTC metastatic to the retropharyngeal and parapharyngeal nodes is a rare occurrence that can be difficult to diagnose due its indolent nature.

Differentiation of neurogenic tumours and pleomorphic adenomas in the parapharyngeal space based on texture analysis of T2WI

BACKGROUND

The purpose of this study was to identify neurogenic tumours and pleomorphic adenomas of the parapharyngeal space based on the texture characteristics of MRI-T2WI.

METHODS

MR findings and pathological reports of 25 patients with benign tumours in the parapharyngeal space were reviewed retrospectively (13 cases with pleomorphic adenomas and 12 cases with neurogenic tumours). Using PyRadiomics, the texture of the region of interest in T2WI sketched by radiologists was analysed. By using independent sample t-tests and Mann‒Whitney U tests, the selected texture features of 36 Gray Level Co-Occurrence Matrix (GLCM) and Gray Level Dependence Matrix (GLDM) were tested. A set of parameters of texture features showed statistically significant differences between the two groups, which were selected, and the diagnostic efficiency was evaluated via the operating characteristic curve of the subjects.

RESULTS

The differences in the three parameters - small dependence low level emphasis (SDLGLE), low level emphasis (LGLE) and difference variance (DV) of characteristics - between the two groups were statistically significant (P < 0.05). No significant difference was found in the other indices. ROC curves were drawn for the three parameters, with AUCs of 0.833, 0.795, and 0.744, respectively.

CONCLUSIONS

There is a difference in the texture characteristic parameters based on magnetic resonance T2WI images between neurogenic tumours and pleomorphic adenomas in the parapharyngeal space. For the differential diagnosis of these two kinds of tumours, texture analysis of significant importance is an objective and quantitative analytical tool.

[Schwannoma of the parapharyngeal space]

Schwannoma is a benign neoplasm that develops from the Schwann cells of the nerve sheath. The share of neurogenic tumors of the parapharyngeal space accounts for 0.5% of all neoplasms of this localization. The article demonstrates a case from practice, presents the clinical features, diagnostics and methods of treatment for patients with pharyngeal neuromas. The peculiarity of the presented clinical observation is due to the rare occurrence of this pathology and the large size of the schwannoma in the long-term asymptomatic course of the disease.

Pre-styloid parapharyngeal space masses-Tumor margins as a predictor of benign versus malignant histology on pre-operative CT or MRI

PURPOSE

Evaluate the frequency of benign versus malignant masses within the prestyloid parapharyngeal space (PPS) and determine if tumor margins on preoperative cross-sectional imaging can predict malignancy status.

MATERIALS AND METHODS

The electronic health record at UC Davis Medical Center was searched for PPS masses surgically resected between 2015 and 2021. Cases located centrally within the prestyloid PPS with confirmed histologic diagnosis were included and separated into either benign or malignant groups. Margins of the tumors were categorized as "well defined" or "infiltrative" on preoperative cross-sectional imaging. Statistical analysis was performed to evaluate relationships between malignancy status and tumor margins.

RESULTS

A total of 31 cases met the inclusion criteria. Fourteen separate histologic diagnoses were observed. Benign cases comprised 77% (24/31) and the remaining 23% (7/31) were malignant. Pleomorphic adenoma was the most common overall diagnosis at 48% (15/31). Adenoid cystic carcinoma 6% (2/31) was the most common malignant diagnosis. Well-defined tumor margins were seen in 81% (25/31) of cases. A benign diagnosis was found in 96% (24/25) of the cases with well-defined margins. Infiltrative tumor margins were displayed in 19% (6/31) of cases, all were malignant. The sensitivity and specificity of infiltrative tumor margins for malignancy were 85.7% and 100%, respectively. The negative predictive value of infiltrative margins for malignancy was 96%.

CONCLUSION

Infiltrative tumor margins on preoperative imaging demonstrate high specificity and negative predictive value for malignant histology in prestyloid PPS masses. Margins should therefore be considered when determining clinical management for newly diagnosed PPS tumors.

Surgical Parapharyngeal Space Tumor Analysis with Case Series Study

Background

The parapharyngeal space is a hypothetical region in the neck that stretches from the base of the skull to the bigger corner of the hyoid bone. The fascia that connects the styloid process to the tensor veli palatini separates the compartment into prestyloid and poststyloid compartments, with the prestyloid compartment being larger. In the general population, tumors of the parapharyngeal area are very uncommon, accounting for less than 1% of all head and neck neoplasms in the population. In this location, CT scanning and magnetic resonance imaging (MRI) exams are complimentary, and both tests should be performed to examine any lesions found. The most critical component of treatment is the total surgical removal of all the cancerous tissue. Identifying and treating primary parapharyngeal space (PPS) tumors are among the most challenging tasks in the treatment of head and neck cancer. They are also among the most aggressive ones. The primary goal of this study is to review our current knowledge at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, which serves as an academic tertiary referral center and a major teaching center. We will focus on clinical findings, tumor structure, tumor histological distribution, and surgical approaches.

Materials and Methods

The processing starts with two modules. The first module starts with the input images obtained from various patients and collected as a database. The second module starts with the collection of case series of nine patients undergoing excision via multiple different approaches: transoral, transcervical, transparotid, transmandibular, or infratemporal approach. All cases were conducted at King Abdulaziz University Hospital in Jeddah, Saudi Arabia, between 2014 and 2018. All operative interventions were performed by an otolaryngology-head and neck surgeon.

Results

Our study comprised nine patients, of which two underwent transparotid and seven transcervical and combined transcervical/transparotid approach. Complications faced included a hematoma in one of our cases.

Conclusion

The transcervical approach appeared to be the superior surgical approach when facing a pleomorphic adenoma within the parapharyngeal space, arising from the deep lobe of the parotid gland or parapharyngeal space-occupying paraganglioma.

A retrospective analysis of surgery in prestyloid parapharyngeal tumors: Lateral approaches vs transoral robotic surgery

OBJECTIVE

Surgery is the standard treatment for most tumors in the prestyloid parapharyngeal space (PPS) but it can be a challenging procedure because of the anatomical complexity of the area. Prestyloid surgery can be performed with various lateral approaches or with a medial approach using transoral robotic surgery (TORS)-either alone or in combination with a transcervical incision. We have retrospectively compared our center's results with lateral and medial approaches.

METHODS

Between 2015 and 2020, 28 patients with prestyloid PPS tumors underwent surgery at our center: 14 with lateral approaches, including transcervical, transcervical-parotid, and transcervical-mandibular, and 14 with medial approaches (12 with TORS and two with TORS plus a transcervical incision). We compared surgical time, postsurgical complications, length of hospital stay, need for feeding tube, and relapse-free survival in the two patient groups.

RESULTS

Pleomorphic adenoma was the most frequent tumor and 60.7% of the tumors were benign. Tumor volume and maximum length were similar in the two groups of patients. Intraoperative image guidance and ultrasound were used in 33% of TORS. TORS was associated with less surgical time, fewer complications, and shorter hospital stays. Recurrence rates were similar in the two groups.

CONCLUSION

The medial approach by TORS offers superior results in prestyloid tumors than the open lateral approach and can be refined by intraoperative guidance. Level of Evidence: 4.

Management of parapharyngeal space tumors with transparotid-transcervical approach: analysis of prognostic factors related with disease-control and functional outcomes

PURPOSE

Different therapeutic strategies have been developed to improve surgical and functional outcome of parapharyngeal space (PPS) neoplasms. The transparotid-transcervical approach (TTa) is a valid surgical option to manage most PPS tumors. Its short- and long-term disease control and cranial nerve (c.n.) function outcomes have not been discussed extensively.

METHODS

All patients who underwent TTa over a 10-year period at a tertiary academic center were retrospectively reviewed. Data about preoperative imaging, clinical presentation, tumor's size, location and histology, and postoperative oncological and functional results were registered and analyzed.

RESULTS

Sixty patients matched the inclusion criteria. Most of the lesions were benign (71.7%), involved the prestyloid PPS (63.3%) and measured more than 30 mm (75%). Fifty-two (86.7%) lesions were resected en-bloc. Clear margins were achieved in 91.7% of the cases, with positive margins solely associated with malignancy (p = 0.008). Post-operative c.n. function was satisfactory, with X c.n. function significantly associated with the retrostyloid location (p = .00) and neurogenic tumors (p = 0.02). Local disease-control was achieved in 96% of the cases after a median follow-up of 46 (± 19.7-82.0 IQR) months.

CONCLUSIONS

The TTa was safe and effective, achieving a satisfactory local control rate. Nevertheless, malignancies maintain a higher rate of positive margin due to their infiltrative nature and the complex anatomy of the PPS. In such cases, multiportal approaches might be more effective. However, post-operative c.n. function remained satisfactory, irrespective of lesions' size and histopathologic behavior. A higher X c.n. deficit rate was observed in retrostyloid and neurogenic lesions.

Transoral Excision of Parapharyngeal Space Tumors

Transoral excision of parapharyngeal space (PPS) tumors has increased in popularity along with the increased use of robotic and endoscopic surgical technology. Here, the authors highlight the indications, techniques, outcomes, and complications of transoral approaches to PPS tumors, with a special emphasis on salivary tumors of the PPS and the transoral robotic surgery approach.

Resection of Parapharyngeal Space Tumors Located in the Prestyloid Compartment: Efficacy of the Cervical Approach

BACKGROUND

Parapharyngeal space tumors are rare. Among them, tumors in the prestyloid compartment are particularly suitable for surgery; however, there are no detailed reports of such surgery and their features remain unknown.

METHODS

We conducted a retrospective cohort study. For 67 surgical cases of benign tumors in this compartment, we examined the patient and tumor characteristics, fine-needle aspiration cytology (FNAC), and intraoperative details such as surgical approach, use of complete excision, and postoperative complications.

RESULTS

Pleomorphic adenomas (PAs) comprised 73.1% of the lesions. The diagnostic accuracy of FNAC to differentiate benign and malignant tumors was 97.7%. Of the treated lesions, 94.0% were removed via the cervical approach alone, including all PAs. The remaining 6.0% were resected via the cervical-parotid approach. The median operative time and bleeding volume were 89 min and 50 mL, respectively. Operative time using the cervical approach was significantly shorter (p = 0.021). All cases could be treated via complete surgical excision. Postoperative complications occurred in 32.8% of patients, with transient slight facial palsy being the most common. No fatal complications occurred and 92.5% of patients had no sequelae. There was no significant association between complications and surgical approach.

CONCLUSION

Based on diagnosis by FNAC, with a high accuracy rate, most benign prestyloid tumors, especially PAs, were resected using the cervical approach alone, with a shorter operative time and without severe complications.

Surgical management of extracranial nerve sheath tumours in a tertiary care center

Objective

Excision of the nerve sheath tumours of head and neck is always a challenge to the surgeon because of their close proximity of the neurovascular structures.

Methods

It is a retrospective study contained 13 consecutive patients of nerve sheath tumours involving the head and neck from March 2013 to February 2017 in the department of Otorhinolaryngology and Head Neck Surgery in a tertiary care referral hospital. The retrospective clinical data, diagnostic procedures, surgical approaches and their complications are analyzed after 12 months of surgery.

Results

Total 13 patients, 7 were females and 6 were males. Painless neck swelling was the most common presentation found in 6 and the most common site of origin was the vagus nerve in the parapharyngeal space (6 patients). Transcervical excision of the tumour was performed in 7 patients. Six needed combined surgical approach for the excision of the tumours. Neurovascular injury was detected in 3 patients, and one patient had recurrent disease during the follow-up period.

Conclusions

Excision of the nerve sheath tumours of head and neck is always a challenge to the surgeon because of their close proximity of the neurovascular structure. Although the transcervical approach is commonly practiced for the majority of the tumours, combined approaches can be effectively applied for extensive nerve sheath tumours with the satisfactory clinical outcome.

Surgical Management of Parapharyngeal Space Tumours in a Single Tertiary Care Center

Because of the inaccessibility and overcrowding of the vital neurovascular structures, management of the parapharyngeal space (PPS) tumour is always a challenge to the surgeons. Here we have discussed the clinical findings and management of the PPS tumours with special concern to the surgical approaches. It is a retrospective study containing 14 patients of PPS tumour from June 2015 to January 2018 in the department of Otorhinolaryngology and Head Neck Surgery in a tertiary care referral hospital. 14 consecutive patients with PPS tumours were included in the study. The retrospective clinical data, diagnostic procedures, surgical approaches and the complications were analyzed after 12 months of surgery. Of 14 patients included in the study, 10 patients were males and 4 were females. Prestyloid and poststyloid spaces were involved in 28.57% and 71.42% cases respectively. Transcervical excision of the tumours were performed in 10 patients, 2 patients had undergone transcervical-transoral approach. Transcervical transmandibular and transcervical transparotid excision of tumours were performed in one patient each. Facial nerve injury was detected in 3(21.42%) patients. Injury to the internal carotid artery and wound infection were detected in one patient each. Radiological imaging, especially the MRI helps by narrowing the spectrum of the differential diagnosis distinguishing the benign from malignant lesions, especially in cases where FNAC is contraindicated. Although the transcervical approach is commonly practiced, the combined surgical approach can be effectively applied specially for extensive PPS tumours associated with satisfactory clinical outcomes.

Tumors of the parapharyngeal space: the VU University Medical Center experience over a 20-year period

Background

Tumors of the parapharyngeal space (PPS) are rare, accounting for 0.5–1.5% of all head and neck tumors. The anatomy of the PPS is responsible for a wide variety of tumors arising from the PPS. This series of 99 PPS tumors provides an overview of the clinical course and management of PPS tumors.

Materials and methods

This retrospective study included clinical data from patients treated for PPS tumors from 1991 to 2012 (warranting at least a 4-year follow-up) at the VU University Medical Center, Amsterdam, The Netherlands.

Results

Fifty percent were salivary gland tumors, 41% were neurogenic and 9% had a different origin. 18.2% of the PPS tumors were malignant. The most reported symptom at presentation was swelling of the neck and throat. In 14%, the PPS tumor was an accidental finding following imaging for other diagnostic reasons. Cytology showed an accuracy rate of 73.1% (19/26). The positive predictive value of a malignant cytology result was 86% (95% CI 42.1–99.6%). Surgery was performed in 55 patients (56%). The most frequently performed approach (56%) was the cervical–transparotid approach, followed by the cervical (25%), transmandibular (16%) and transoral (2%) approach. Nine patients died of the disease, of which seven patients had a malignant salivary gland tumor, one patient had a pleomorphic adenoma at first diagnosis which degenerated into carcinoma ex pleomorphic adenoma and one patient died of metastatic renal cell carcinoma.

Conclusion

This large single-centre report on PPS tumors shows that careful diagnostic work up and proper surgical planning are important in this specific and rare group of head and neck tumors. Surgery was the main treatment (56%) for parapharyngeal tumors. Management of parapharyngeal neurogenic neoplasms generally consists of active surveillance due to peri-operative risk for permanent cranial nerve damage. The histopathological diagnoses were consistent with previous reports.

Endocrine tumors associated with the vagus nerve

The vagus nerve (cranial nerve X) is the main nerve of the parasympathetic division of the autonomic nervous system. Vagal paragangliomas (VPGLs) are a prime example of an endocrine tumor associated with the vagus nerve. This rare, neural crest tumor constitutes the second most common site of hereditary head and neck paragangliomas (HNPGLs), most often in relation to mutations in the succinate dehydrogenase complex subunit D (SDHD) gene. The treatment paradigm for VPGL has progressively shifted from surgery to abstention or therapeutic radiation with curative-like outcomes. Parathyroid tissue and parathyroid adenoma can also be found in close association with the vagus nerve in intra or paravagal situations. Vagal parathyroid adenoma can be identified with preoperative imaging or suspected intraoperatively by experienced surgeons. Vagal parathyroid adenomas located in the neck or superior mediastinum can be removed via initial cervicotomy, while those located in the aortopulmonary window require a thoracic approach. This review particularly emphasizes the embryology, molecular genetics, and modern imaging of these tumors.

Parapharyngeal space tumors: Fifty-one cases managed in a single tertiary care center

CONCLUSIONS

Pre-operative planning for parapharyngeal tumors must include meticulous analysis. Factors such as tumor size, distance to cranial base, and relation to neurovascular structures must guide the selection of a surgical approach.

OBJECTIVE

To summarize experience in diagnosis and surgical management of parapharyngeal tumors, analyzing the frequencies of various tumoral types, clinical presentation, choice of surgical approach and outcomes. This study also compares the results with the most relevant case series in the literature.

METHODS

A retrospective review was performed of the records of 51 patients treated by the team, from 1984-2012. Only primary tumors were included, excluding invasion from adjacent spaces and metastatic disease. All patients underwent imaging studies and surgical resection of the neoplasm. Cytological analysis and arteriography were used on an individualized basis. Surgical excision was performed via different approaches, predominantly through a cervicoparotid route.

RESULTS

Benign neoplasms were predominant (80%), and the most frequent tumor was pleomorphic adenoma. FNAC had a 100% accuracy to differentiate benign vs malignant tumors. The most common post-operative sequel was compromise of a cranial nerve, and three patients presented local complications after surgery. After follow-up, only three of 41 patients with benign tumors had recurring disease.

A modified method for locating parapharyngeal space neoplasms on magnetic resonance images: implications for differential diagnosis

The parapharyngeal space (PPS) is an inverted pyramid-shaped deep space in the head and neck region, and a variety of tumors, such as salivary gland tumors, neurogenic tumors, nasopharyngeal carcinomas with parapharyngeal invasion, and lymphomas, can be found in this space. The differential diagnosis of PPS tumors remains challenging for radiologists. This study aimed to develop and test a modified method for locating PPS tumors on magnetic resonance (MR) images to improve preoperative differential diagnosis. The new protocol divided the PPS into three compartments: a prestyloid compartment, the carotid sheath, and the areas outside the carotid sheath. PPS tumors were located in these compartments according to the displacements of the tensor veli palatini muscle and the styloid process, with or without blood vessel separations and medial pterygoid invasion. This protocol, as well as a more conventional protocol that is based on displacements of the internal carotid artery (ICA), was used to assess MR images captured from a series of 58 PPS tumors. The consequent distributions of PPS tumor locations determined by both methods were compared. Of all 58 tumors, our new method determined that 57 could be assigned to precise PPS compartments. Nearly all (13/14; 93%) tumors that were located in the pre-styloid compartment were salivary gland tumors. All 15 tumors within the carotid sheath were neurogenic tumors. The vast majority (18/20; 90%) of trans-spatial lesions were malignancies. However, according to the ICA-based method, 28 tumors were located in the pre-styloid compartment, and 24 were located in the post-styloid compartment, leaving 6 tumors that were difficult to locate. Lesions located in both the pre-styloid and the post-styloid compartments comprised various types of tumors. Compared with the conventional ICA-based method, our new method can help radiologists to narrow the differential diagnosis of PPS tumors to specific compartments.

Primary parapharyngeal tumours: a review of 21 cases

BACKGROUND

The diagnostic and therapeutic procedures performed in a series of patients with primary parapharyngeal space (PPS) tumours treated at the ENT Departments of San Giovanni Bosco Hospital, Turin, and of the Pugliese-Ciaccio Hospital, Catanzaro, Italy, in the period 2001-2010 are evaluated.

MATERIALS AND METHODS

The retrospective review included 20 patients, 11 male and 9 female, average age of 41 years operated on for 21 primary PPS tumours. The most common tumours found were neurogenic neoplasms, while those of salivary origin were the next most common.

RESULTS

There were 14 paragangliomas (7 originating from carotid glomus, 5 from vagal and 2 from tympanicum), 1 sympathetic chain schwannoma and 6 pleomorphic adenomas. All the tumours were benign in nature and gave rise to few signs or symptoms. Patients underwent preoperative computed tomography (CT) scan or magnetic resonance imaging (MRI) or both. Most contrast-enhanced masses were submitted to some type of angiography. Most of the surgeries were planned through imaging alone, as preoperative fine needle aspiration (FNA) biopsy was performed only in six cases. Four different approaches were adopted for tumour removal: transcervical, transcervical/transparotid, cervical-transparotid-transmandibular and infratemporal fossa approach. There was no operative mortality, though neurologic morbidity was significant. Follow-up, extended to a maximum of 11 years, did not reveal any recurrences. In conclusion, neurogenic tumours may be the most common of PPS masses. Surgery is the mainstay treatment and external approaches offer the potential for satisfactory tumour resection. Of such external approaches, transcervical and cervical/transparotid are the most often used in benign forms.

CONCLUSION

The number of perioperative complications encountered in this series confirms the difficulty of performing surgery in this complex area, even in benign cases. The chances of avoiding vascular damage and saving the trunks or most of the nerve fibres involved depend not only on the skill and experience of the surgeon but also on the anatomy of the lesion, the type of connection between the tumour and the nerve from which it originates and the distribution of neural fibres in or around the tumour mass.

Clinicopathologic study of parapharyngeal tumors

BACKGROUND

Parapharyngeal space (PPS) tumors are rare. Three main groups are identified, namely those of salivary origin, neurogenic tumors and paragangliomas. Early pathological classification of PPS tumors is important for pin point diagnosis and timely management.

AIMS

The PPS is a complex anatomical potential space and poses high risk of per and postoperative complication. This study was done to perform optimum preoperative evaluation by clinicoradiologic correlation and guided fine needle aspiration cytology (FNAC) which is essential to minimize intraoperative risk.

MATERIALS AND METHODS

Guided FNAC was carried out to diagnose parapharyngeal tumors in 48 patients from January 2008 to January 2010. The inflammatory lesions were excluded in the present study. Correlation with histopathology was done in all the cases.

RESULTS

The mean age for all the patients was 38.2 years. There were 23 male and 25 female subjects. Seventy nine percent of the lesions were benign with pleomorphic salivary adenoma being the commonest, while only 20.8% of the lesions were malignant. All the patients presented with neck swelling. No complication was encountered in the present study.

CONCLUSION

FNAC can replace incisional biopsy which may be hazardous in this area. Immediate treatment can be planned based on the FNAC report.

Deep lobe parotid pleomorphic adenoma presenting as obstructive sleep apnoea

We present a rare case of obstructive sleep apnoea (OSA) secondary to a deep lobe parotid pleomorphic adenoma and discuss its management, including the need for a thorough examination and multidisciplinary approach. Only a few cases of pleomorphic adenoma of the deep lobe of the parotid gland causing OSA have been reported. Our case is not only extremely rare but also highlights that key diagnoses maybe missed if a thorough assessment is not performed.

Parotid tail pleomorphic adenoma extending to the parapharyngeal space

Parapharyngeal space tumors are rare, accounting for 0.5% of head and neck neoplasms. Most of them are benign and originate in the salivary glands, especially the pleomorphic adenoma. We presented a 47-year-old man with parotid tail pleomorphic adenoma extending to the parapharyngeal space. The patient applied to our clinic with the complaints of a painless mass on his neck and in his mouth for 3 months. After fine needle aspiration biopsy, the mass was diagnosed as pleomorphic adenoma. The patient was hospitalized and operated in our clinic. As we see in literature review, parapharyngeal space tumors are rare, and most of them are pleomorphic adenomas arising from the deep lobe of the parotid gland and extend into the PPS.

Cervical sympathetic chain schwannoma: a case report

Tumors originating in the parapharyngeal space are rare and are fascinating to the surgeon in view of the anatomical complexity of the area, varied histological type of tumors encountered and the impressive size which some of these tumors attain before becoming clinically evident. We report a rare case of schwannoma arising from the cervical sympathetic chain presenting as a mass in the parapharyngeal space.

[Anatomy and surgical approaches to the parapharyngeal space]

PURPOSE

Analysis of surgical approaches to primary tumors localized in parapharyngeal space used in Head & Neck Cancer Department, Cancer Center Institute in Warsaw. Description of differences in terminology used to describe fascial compartments of the neck.

MATERIAL AND METHODS

Retrospective analysis of medical records of 8 selected patients who had an operation for primary parapharyngeal space neoplasm. Analysis has been done of operation protocols, diagnostic images, tumor size and histopathology.

RESULTS

Transcervical, transparotid and transmandibular approaches were used with additional rhinotomy and craniotomy in selected cases. Selection of approach should take into account tumor localization, its size and histopathology.

CONCLUSIONS

Planning of surgical procedure for parapharyngeal space tumor should be based upon analysis of diagnostic images and selection of the approach depends on tumor localization, size and histopathology. Differences in terminology of superficial and middle cervical fascial compartments can lead to inappropriate clinical decisions.

Rare metastases of differentiated thyroid carcinoma: pictorial review

Differentiated thyroid cancer (DTC) is usually indolent with good prognosis and long-term survival. However, DTC distant metastasis is often a grave event and accounts for most of its disease-specific mortality. The major sites of distant metastases are the lung and bone. Metastases to the brain, breast, liver, kidney, muscle, and skin are rare or relatively rare. Nevertheless, recognizing rare metastases from DTC has a significant impact on the clinical decision making and prognosis of patients. (131)I single photon emission computed tomography/computed tomography ((131)I-SPECT/CT) can provide both metabolic and anatomic information about a lesion; therefore, it can better localize and define the (131)I-WBS findings in DTC patients. In this pictorial review, the imaging features of a range of rare metastases from DTC are demonstrated, with a particular emphasis on the (131)I-SPECT/CT diagnostic aspect.

Management of parapharyngeal giant pleomorphic adenoma

INTRODUCTION

Pleomorphic adenoma (PA) is found rarely in the parapharyngeal space (PPS). Because of late diagnosis due to slow growth, close proximity to vital neurovascular structures and risks of surgery, it poses a great difficulty for both diagnosis and surgical management. The preferred surgical approach to the PPS is the cervical-transparotid including a total parotidectomy with facial nerve preservation combined with a cervical access for dissection of cranial nerves and vascular structures thus allowing a safe removal of the tumor together with the parotid deep lobe. We report herein our experience in the management of giant PAs involving the prestyloid PPS and describe a not well-documented transparotid route by preservation of the parotid superficial lobe in combination with an intraoral approach.

PATIENTS AND METHODS

In this retrospective study, three cases of patients having giant PAs involving the PPS are evaluated. All patients had signs of foreign body sensation in the throat and a growing mass bulging in the oropharynx. Diagnosis was based on MRI and upon preoperative intraoral biopsy. The average tumor size was 5.7 cm. Patients underwent surgery and excision of tumors via transparotid-intraoral approach. In two cases, the superficial lobe was preserved and afterwards put back in its anatomic location.

RESULTS

All patients were discharged without complications, and no recurrences were observed.

CONCLUSIONS

Preoperative diagnosis management of PPS giant tumors should be based on imaging and upon open transoral biopsy if possible. The transparotid-intraoral approach provided adequate visibility to remove large PAs involving the prestyloid PPS.

Localization and identification of parapharyngeal metastases from differentiated thyroid carcinoma by 131I-SPECT/CT

BACKGROUND

Parapharyngeal metastasis is a rare event in differentiated thyroid carcinoma (DTC). The (131) I-single photon emission CT (SPECT)/CT allows better localization and definition for metastases in DTC. The aim of this study was to assess the value of (131) I-SPECT/CT for the diagnosis of parapharyngeal metastasis in patients with DTC.

METHODS

Consecutive patients with DTC (n = 561) treated with (131) I for the ablation of remnant or treatment of metastases were enrolled. A (131) I-SPECT/CT was performed when there were abnormal findings indicative of parapharyngeal metastasis on (131) I-whole-body scan (WBS).

RESULTS

A total of 15 lesions were found to be parapharyngeal metastasis in 14 of 561 patients with DTC after the use of (131) I-SPECT/CT. The incidence rate of parapharyngeal metastasis was about 2.5% in DTC. Of the 15 lesions, only 5 lesions were CT-positive. The remaining 10 lesions were either ignored or indeterminate by the CT alone.

CONCLUSION

The (131) I-SPECT/CT can identify parapharyngeal metastasis at an early stage. Parapharyngeal metastasis in DTC is relatively frequent after the use of (131) I-SPECT/CT.

Novel use of ultrasound-guided endo-cavitary probe to evaluate an impalpable parapharyngeal mass

Aim:

We present a novel, previously undescribed technique of obtaining a biopsy from an inaccessible parapharyngeal space mass.

Method:

A modified endo-cavitary ultrasound probe was utilised to obtain an intra-oral, image-guided core biopsy of a parapharyngeal tumour. The parapharyngeal mass was not accessible to percutaneous ultrasound-guided biopsy due to its anatomical location.

Conclusion:

To our knowledge, this is the first such modification of the conventional endo-cavitary probe technique described in the literature. The technique permits accurate, well controlled biopsy of lesions located high in the parapharyngeal space, under general anaesthesia.

Surgical management of parapharyngeal tumors - our experience

Fifteen cases of parapharyngeal tumors treated surgically in ENT department of Calcutta National Medical College in last 2 years were included, 80% cases were of benign tumors, most common being schwannomas. Most important investigation was found to be CT scan. The study gives an overview regarding the surgical approach, based upon the extent and histology of the tumor and transcervical approach was found to be most efficient for all practical purpose.

[Diagnostic and therapeutic problems in parapharyngeal space tumor--case report]

Only 0.5% of head and neck tumors originate from parapharyngeal space. Malignant neoplasms of parapharyngeal space are exceptionally rare (20% of all tumors in this area). Their rarity form a complex diagnostic and therapeutic problem. Authors reports a case of 53-year old woman with squamous cell carcinoma of parapharyngeal space that caused particular difficulties in diagnosis. Diagnostic and therapeutic procedures and preliminary outcome of treatment are presented.

Parapharyngeal paraganglioma: diagnosis on fine-needle aspiration

Carotid body tumors constitute the third commonest group of parapharyngeal tumors. Newer diagnostic modalities such as computed tomography scan, magnetic resonance imaging, and Doppler ultrasound are commonly used for diagnosing lesions at this site. However, simple technique of fine-needle aspiration (FNA) cytology is rarely performed in apprehension of complication of hemorrhage. Present case report is of carotid body paraganglioma diagnosed on FNA without any complications and thus providing definite preoperative diagnosis to the surgeon.

Tumoración parafaríngea metastásica de carcinoma papilar de tiroides

This is a case report of a papillary thyroid carcinoma metastatic to the parapharyngeal space, that presented with local obstructive symptoms (dysphagia and displacement of the ipsilateral tonsil). The diagnosis was suspected by imaging studies (CT and MRI) but not confirmed until histological examination. It is not common for such tumors to metastasize to the parapharyngeal space. This is the reason why, to our knowledge, there have been described only five similar cases previously.

Roof of the parapharyngeal space: defining its boundaries and clinical implications

The roof of the parapharyngeal space (PPS) is poorly defined. Although it is generally described as having prestyloid and poststyloid compartments, we believe that these terms are imprecise. Therefore, we define its boundaries, partition, and compartments. We completed macroanatomical and microanatomical dissections in 10 specimens from 5 human cadaver heads; bone measurements in 50 dry skulls; and axial and coronal cross-sectional studies in 2 cadaveric specimens. The PPS roof is bordered laterally by the medial pterygoid fascia and medially by the pharyngobasilar fascia. The tensor veli palatini fascia (TVPF) partitions this roof into an anterolateral compartment containing fat and part of the deep lobe of the parotid gland, and a posteromedial compartment containing the cartilaginous part of the eustachian tube, internal carotid artery, internal jugular vein, and cranial nerves IX through XII. The anteroposterior length measures 32 mm (range, 26.1 to 36.9 mm), and the mediolateral width measures 16.3 mm (range, 12.1 to 21.3 mm). The PPS roof has 3 important bony landmarks (ie, scaphoid fossa, styloid process, sphenoid spine); 3 important fasciae (ie, medial pterygoid fascia, TVPF, pharyngobasilar fascia); and 2 compartments, which are anterolateral and posteromedial to the TVPF. We believe that this is the first report to specifically focus on the roof of the PPS.

Pediatric tumors of the parapharyngeal space. Three case reports and a literature review

Three cases of pediatric primary parapharyngeal space tumors, namely a Burkitt's lymphoma, lipoblastoma and a ganglioneuroma are described here, along with a literature review. These disorders are very rare, accounting for less than 20% of all parapharyngeal neoplasms. In comparison to adults, there are differences in pathomorphologic spectrum of pediatric parapharyngeal tumors. The authors describe the prevalence of malignant tumors, mainly soft tissues sarcomas. The salivary gland tumors and paragangliomas which dominate in adult populations, are extremely rare in pediatric populations where the most common benign tumor to be encountered is that of neurogenic origin. It follows that these features modify the diagnostic and therapeutic approach.

Parapharyngeal lymph node metastasis: An unusual presentation of papillary thyroid carcinoma

BACKGROUND

Parapharyngeal space nodal metastases are usually secondary to malignancies of the pharynx and sinonasal tract, although localization of lymphomas is also possible. Parapharyngeal metastases arising from thyroid papillary carcinoma are instead an exceedingly rare event, with only 10 cases reported up to now in the literature.

METHODS

We describe two cases of parapharyngeal metastasis from thyroid papillary carcinoma in a man and a woman, aged 40 and 52 years, respectively.

RESULTS

Both patients had a lesion that clinically appeared to be located in the parapharyngeal space; they underwent CT and MRI, which detected a cystic mass in the poststyloid compartment. In the first patient, fine-needle aspiration cytology failed in identifying the histologic nature of the lesion, which was excised through a transcervical approach. A diagnosis of metastatic thyroid papillary carcinoma was rendered and therefore the patient underwent total thyroidectomy. In the second patient, a total thyroidectomy, previously scheduled for multinodular goiter, was performed along with the removal of the parapharyngeal mass. Definitive histologic findings revealed that the two parapharyngeal masses were cystic metastases from a thyroid papillary carcinoma. Both patients received postoperative 131I treatment. Twenty-four months after surgery, the first patient is free of disease, whereas the second one has clear signs of abnormal 131I uptake in the lungs.

CONCLUSIONS

The differential diagnosis of a parapharyngeal poststyloid mass should also include metastasis from thyroid papillary carcinoma. When the lesion displays a cystic appearance on imaging, it is advisable to rule out a thyroid primary by ultrasonographic examination. The occurrence of a metastasis in such unusual site, even though rarely reported, does not seem to significantly affect the prognosis of the disease.