Accessory parotid gland lesions: case report and review of literature

Endoscopic-assisted resection of pleomorphic adenoma in the accessory parotid gland

Background : An accessory parotid gland (APG) is a common anatomical structure that occurs in 10%-56% of individuals. Pleomorphic adenomas are the most common benign tumors of the APG, and their ideal treatment is surgical excision, although there is a risk for aesthetic disorders and facial nerve damage due to the site of origin. Moreover, despite being benign, these tumors are known to recur. Therefore, it is necessary to achieve both reliable excision and avoidance of facial nerve damage. Case presentation : We report a case of a 49-year-old Japanese man with a mass in his left cheek. The lesion was diagnosed as a benign salivary gland tumor derived from the APG by computed tomography imaging, magnetic resonance imaging and fine needle aspiration cytology. We resected the tumor using modified high submandibular incision under the endoscopic-assisted field of view. Discussion and Conclusions : The tumor was less invasive and reliably resected using an endoscope. In surgical treatment, the endoscopic-assisted technique is very useful to achieve complete tumor resection and prevent relapse while avoiding serious complications due to surgical procedures. J. Med. Invest. 68 : 376-380, August, 2021.

Ten must know pseudolesions of the head and neck

Patients may present in the emergency setting for a variety of head and neck complaints such as fever, trouble swallowing, or a newly palpable mass. When reviewing radiologic head and neck exams for etiology of complaints, it is important to be familiar with the multiple pseudolesions that may mimic pathology. These may be normal variant anatomy, normal anatomy located in an atypical location, as well as iatrogenic or self-introduced foreign bodies. This review article discusses ten common pseudolesions encountered in the head and neck and their typical imaging appearance so that one does not mistake them for ominous pathology, thus preventing unnecessary follow-up, biopsy, or continued concern for the patient.

Role of Salivary Duct Morphology in the Etiology of Chronic Obstructive Parotitis: Statistical Analysis of Sialographic Features and Computational Fluid Dynamics Analysis of Salivary Flow

PURPOSE

The causes of some cases of chronic obstructive parotitis (COP) without obstructive factors are still unclear. The authors hypothesized that some morphologic features of salivary ducts might contribute to the development of COP. This study investigated the role of salivary duct morphology in the etiology of COP.

MATERIALS AND METHODS

The authors designed and implemented a case-and-control study. Cases were defined as patients with COP, diagnosed from September 2014 to May 2017 at the Affiliated Hospital of Stomatology of the Sun Yat-sen University (Guangzhou, China), and controls were healthy participants. The primary predictor variables were the occurrence of an accessory duct (AD), the number of branches uniting to form the Stensen duct (SD), the angle between the AD and the SD, and the angle between branches identified on sialographic computed tomograms. Data from the 2 groups were compared to investigate the association between these variables and COP. The χ² test, Student t test, and logistic regression were computed, with significance set at a P value less than .05. Fluid dynamics analysis was used to analyze salivary flow field in models of salivary ducts with different morphologic features reconstructed from sialographic computed tomograms.

RESULTS

The sample was composed of 39 patients with COP and 18 controls without COP. The 2 groups were not similar for incidences of an AD (71.8 vs 38.9%) and the angle between branches (96.5 ± 26.0° vs 71.5 ± 21.2°). There was no relevant difference between groups in the number of branches and the angle between the AD and the SD. The area of low velocity was larger in the model with the wider angle between branches.

CONCLUSIONS

The results suggest that the presence of an AD and a wider angle between duct branches are associated with COP.

Pathology and management of masses in the accessory parotid gland region: 24-year experience at a single institution

PURPOSE

Masses in the accessory parotid gland (APG) region are clinically rare and their management can lead to conflicts between the need for tumor resection and facial cosmesis. The aim of this study was to analyze the pathological classifications and management of APG lesions in our hospital.

MATERIALS AND METHODS

From January 1993 to March 2017, 130 patients with primary tumors in the APG region who underwent surgical treatment were enrolled. Follow-up surveys after surgery were then carried out.

RESULTS

Among the 130 patients, 53.8% of lesions were benign (n = 70), 23.8% were malignant (n = 31), 14.6% were vascular malformations (n = 19), 6.15% were sialadenitis (n = 8), and 1.65% were cysts (n = 2). Pleomorphic adenoma accounted for 67.1% of the benign tumors (n = 47). Lymphoma, lymphoepithelial carcinoma, and acinar cell carcinoma topped the list of malignant tumors (5 cases in each group). Surgery and surgery plus radio-chemotherapy were performed for benign and aggressive malignant lesions, respectively. At the time of follow-up, 5-year overall survival was 88.1%; mean follow-up was 139 months (range 3-281 months).

CONCLUSIONS

Masses in the APG region have complicated pathological types. Perfect preoperative preparation, with fine-needle aspiration biopsy and imaging examinations, would contribute to identifying characteristics. Treatment schedules and surgical approaches should be determined according to the cytology reports and frozen-section examinations before and during operation.

Salivary duct cyst of accessory parotid gland in contact with the temporomandibular joint

A 60-year-old woman presented with a painless swelling in the right preauricular region. Physical examination revealed a soft, nontender, oval-shaped lump in this location. Computed tomography indicated an anterolateral cystic lesion that was attached to the condyle of the mandible and to the accessory parotid gland. Differential diagnoses included ganglion cyst, synovial cyst of the temporomandibular joint, and accessory parotid gland cyst. Surgical removal of the cyst was performed with the patient under general anesthesia. The specimen was 18 × 20 × 18 mm in size; it contained fluid that was clear, slightly yellow, and amylase positive. Hematoxylin and eosin staining revealed that a bilayer cuboidal epithelium lined the cyst wall. Immunohistochemical analyses of the cyst wall showed strong expression of cytokeratin and weak expression of vimentin. The final diagnosis was a salivary duct cyst. The postoperative course was uneventful except for a transient facial motor paresis.

Sialolithiasis of an Accessory Parotid Gland Causing Mid-Cheek Pain

A 52-year-old woman presented with a slightly painful swelling of the right cheek area without postprandial aggravation of the symptom last 1 week. On physical examination, an approximately 1.5 cm sized firm, slightly tender mass was palpated on the right mid-cheek region, and she did not show any abnormal findings on neurologic examination. Computed tomography showed a well-enhanced lesion with low density of internal portion in right cheek area, and tiny calcification was noted within internal low-density portion of cheek mass. These findings suggested sialolithiasis of an accessory parotid gland with duct dilatation. Mid-cheek pain with conservative medical treatment was resolved and has not occurred during 1 year follow-up.

Role of the Accessory Parotid Gland in the Etiology of Parotitis: Statistical Analysis of Sialographic Features

This retrospective study aimed to identify if the existence of the accessory parotid gland correlated with the etiology of parotitis. This may aid the development of better treatment strategies in the future. Sialographic features of cases with parotitis and healthy subjects were reviewed. The chi-square test was used to compare the incidence of accessory parotid gland between the groups. The Student's t test was used to compare the length of Stensen's duct, the length from the orifice to the confluence of the accessory duct, and the angle between the accessory duct and Stensen's duct between the groups. The incidence of accessory parotid gland in patients with parotitis was 71.8% (28/39), which was significantly higher than that in healthy subjects (P = 0.005). Patients with parotitis had a longer Stensen's duct than healthy subjects (P = 0.003). There was no significant difference in the length from the orifice to the confluence of the accessory duct or the angle between the accessory duct and Stensen's duct (P = 0.136 and 0.511, respectively) between the groups. The accessory parotid gland might play a role in the pathogenesis of parotitis. The existence of an accessory parotid gland is likely to interfere with salivary flow. Computational fluid dynamics analysis of salivary flow in the ductal system would be useful in future etiologic studies on parotitis.

Review of accessory parotid gland tumors: pathologic incidence and surgical management

OBJECTIVE

The current study presents our experience with accessory parotid gland masses and reviews the literature on accessory parotid tumor incidence and surgical management. Based on our results, we advocate a standard parotidectomy approach with routine facial nerve dissection at the time of excision.

STUDY DESIGN

We performed a retrospective chart review and comprehensive literature review on incidence of accessory parotid gland neoplasms.

METHODS

A retrospective chart review of all patients with mid-cheek masses treated by the senior author was conducted from January 2003 to January 2009. The tumor size at presentation, FNA biopsy, pathologic diagnosis, and surgical treatment were recorded for 13 patients.

RESULTS

In the case series, 54% of lesions were benign (n=7) and 46% were malignant (n=6) including benign pathologies of 4 pleomorphic adenomas, 2 lymphadenitis, 1 monomorphic adenoma and malignant pathologies of 2 mucoepidermoid carcinoma, 2 B-cell lymphomas, 1 adenocarcinoma, and 1 myofibrosarcoma. Surgical intervention was performed on all patients with standard parotidectomy incision for accessory parotid mass excision after identification and tracing of facial nerve and its branches.

CONCLUSION

The present study provides support for a standard parotid incision with identification of the facial nerve at the time of surgical incision as this resulted in successful excision of accessory parotid tumors with favorable cosmetic results and without facial paralysis or tumor recurrence. Literature review of 152 cases of accessory parotid gland lesions, revealed a pooled incidence of 70% benign and 30% malignant.

Clinical management of masses arising from the accessory parotid gland

OBJECTIVE

Accessory parotid lesions are clinically rare and its management remains poorly understood. The aim of this study was to analyze the clinical management of accessory parotid lesions.

STUDY DESIGN

From April 1999 to November 2008, a retrospective analysis of 32 patients with accessory parotid lesions was performed. The preoperative examinations, surgical treatment, and prognosis were recorded and analyzed.

RESULTS

Among the 32 patients, there were 8 men and 24 women with an overall average age of 45 years. These patients always presented without obvious symptoms, and the masses were moderate to hard in hardness without tenderness, mobile, and with clear boundary. The pathologic diagnoses were 24 benign and 8 malignant lesions. Surgery and surgery plus radiotherapy were performed in the patients with benign and malignant lesions, respectively, with good prognosis.

CONCLUSIONS

Accessory parotid lesions are rare, and the clinical manifestation is always the same for benign tumors. Surgical resection and surgical resection plus radiotherapy are the primary choices of treatment for benign and malignant lesions, respectively. The prognosis is always good.