Large retention cyst of the accessory parotid gland associated with a mucoepidermoid tumor in the cyst wall

Malignant Mucoepidermoid Tumor Arising in the Accessory Parotid Gland: A Case Report

Purpose: The head and neck surgeon’s fascination with parotid surgery arises from the gland’s spectrum of histopathological presentations, as well as the diversity of its morphological features. A mass arising in the mid-cheek region may often be overlooked as a rare accessory lobe parotid neoplasm. This report serves to revisit the topic of accessory parotid gland neoplasms to emphasize proper management, particularly the surgical aspects, so that consequences of salivary fistula, facial nerve paralysis, and recurrence are avoided. Case report: We report a case of mucoepidermoid carcinoma which was assessed pre-operatively as arising from the accessory parotid gland of a 11-year-old female. She had complained of a painless and round mass of the left cheek for a duration of 12 months. Sialography, ultrasonography, CT scan and MRI were performed preoperatively. Sialography revealed a small duct separating from the Stensen’s duct. CT and MRI showed that the tumor with smooth outline was lying on the masseter muscle and detached from the main parotid gland. The preoperative diagnosis was an accessory parotid gland tumor. The tumor was removed without facial nerve injury via standard parotidectomy incision. The tumor was composed of mucous, intermediate and epidermoid cells. The pathological diagnosis was low-grade mucoepidermoid carcinoma. Conclusions: Accessory parotid gland neoplasms are rare and may present as innocuous extraparotid mid-cheek masses. A high index of suspicion, prudent diagnostic skills (including fine-needle aspiration [FNA] biopsy followed by computed tomography [CT] imaging), and scrupulous surgical approach (extended parotidectomy-style incision and limited peripheral nerve dissection when possible) are the keys to successful management of these lesions.

Mucoepidermoid carcinoma mimicking a mucocele (ranula) in the floor of the mouth

Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy. The submandibular gland is rarely involved, about less than 10% of all other major salivary glands. We report a case of a 49-year-old female who presented with a mass on the left side of the floor of the mouth. She was complaining of neck pain for the last 2-3 days and had noticed the mass growing in size and becoming tender to palpation. There was no exacerbation of pain during eating, drinking, or opening of mouth. A multidetector CT scan was made. The radiographic examination revealed a mostly well-defined hypodense area suggestive of mucocele (ranula), which was thought to be corroborated by the clinical findings. The treatment of choice was the complete excision of the mucocele and the left submandibular salivary gland. The histopathological examination surprisingly revealed a low-grade MEC. No further treatment was recommended; however, a follow up was scheduled in 4 months. This atypical location of MEC in the floor of the mouth simulated the clinical and radiographic features of a mucocele. This case highlights the value and importance of using all the available diagnostic tools and modalities for optimal patient management, as the histopathological analysis played an important role to confirm the diagnosis.

[Clinical features of accessory parotid gland tumors]

Accessory parotid gland tumors are relatively rare; hence, adequately detailed clinical analyses of these tumors are difficult to perform at a single institution. In this report, we describe the findings for 65 patients [29 men, 36 women; median age, 51 (9-81) years] with accessory parotid gland tumors, consisting of 4 cases documented by us and 61 cases previously reported by other Japanese authors. Approximately 50% of the patients were treated in an otolaryngology department, while the remaining patients were treated in plastic surgery, oral surgery, or dermatology departments. In 4 patients, the results of preoperative fine-needle aspiration cytology indicated that the tumor was benign; however, the postoperative histopathology results revealed malignant tumors. The frequencies of malignant and benign tumors were 44.6% (n = 29) and 55.4% (n = 36), respectively. Mucoepidermoid carcinoma and pleomorphic adenoma were the most frequent types of malignant and benign accessory parotid gland tumors, respectively. Among the various surgical methods that were used, such as direct cheek and intraoral incisions, a standard parotidectomy incision was the most preferred treatment approach for these tumors. Recently, an endoscopic approach has also been found to yield satisfactory results. An optimal approach should be selected after evaluating the advantages and disadvantages of these methods. No definite guidelines are available regarding the choice of elective neck dissection and postoperative radiation therapy for malignant accessory parotid gland tumors. Although tumor resection (plus elective neck dissection) and postoperative radiation therapy have been frequently performed for various kinds of malignant accessory parotid gland tumors to date, additional studies are needed regarding the criteria for selecting elective neck dissection and postoperative radiation therapy. Since the malignancy rate for accessory parotid gland tumors is higher than that for parotid gland tumors, the possibility of malignancy (especially mucoepidermoid carcinoma and carcinoma ex pleomorphic adenoma) should be considered when resecting accessory parotid gland tumors, even if the results of preoperative fine-needle aspiration cytology indicate that the tumor is benign.

Adenoid cystic carcinoma associated with mucous retention cyst of the parotid gland

Mucous retention cysts of the parotid gland are rare, and a coexistent adenoid cystic carcinoma is even an unusual occurrence. Such coexistent adenoid cystic carcinomas with mucous retention cyst of the parotid gland are difficult to diagnose clinically and, at times, stage difficulty in their management. We report a rare case of adenoid cystic carcinoma associated with mucous retention cyst of the parotid gland with its diagnostic and management dilemma in a 14-year-old adolescent girl.

Lesions of the accessory parotid gland in children

The accessory parotid gland, a little-known and seldom-mentioned anatomical variant, is a nodule of normal salivary tissue separate from the main parotid gland, located on the masseter muscle and connected to the Stensen duct at that level. It can be the site of both congenital and acquired lesions.

Accessory parotid gland masses

Three cases of accessory parotid gland lesions are reported. The literature concerning accessory gland disease and its diagnosis and treatment is reviewed.

Mucoepidermoid carcinoma arising in the accessory parotid gland

A rare case of a 9-year-old female with mucoepidermoid carcinoma arising in the accessory parotid gland is reported. She had complained of a painless and round mass of the left cheek for a duration of 14 months. Sialography, ultrasonography, CT scan and MRI were performed preoperatively. Sialography revealed a small duct separating from the Stensen's duct. CT and MRI showed that the tumor with smooth outline was lying on the masseter muscle and detached from the main parotid gland. The preoperative diagnosis was an accessory parotid gland tumor. The tumor was removed without facial nerve injury via standard parotidectomy incision. The tumor was composed of mucous and epidermoid cells. The pathological diagnosis was low-grade mucoepidermoid carcinoma.

Mucocele mimicking a Warthin's tumour recurrence

We report an unusual case of an extravasation mucocele complicating superficial parotidectomy. The tumour excised was a Warthin's tumour. Three months following the primary surgery a cystic lesion appeared in the parotid bed. It was initially thought to represent a recurrence. The area was re-explored and a mucocele excised. The pathogenesis of mucoceles and the difficulties encountered when dealing with parotid tumour recurrence are discussed.

Primary squamous cell carcinoma of accessory parotid gland duct epithelium: report of a case

A rare case of primary squamous cell carcinoma surrounding Stensen's duct in a 75-year-old man is presented. The tumor was a relatively well-defined, hard, subcutaneous mass, measuring 18 x 14 x 9 mm and situated in the right cheek. Microscopic examination of an excisional biopsy specimen revealed tumor cells showing squamous differentiation, a papillary growth pattern, and ductal structures with comedo necrosis. Immunohistochemical studies showed positive reactivity for KL-1 (cytokeratin, monoclonal), epithelial membrane antigen, and carcinoembryonic antigen in some tumor cells. The origin of the tumor was thought to be the accessory parotid gland duct epithelium.

Surgical management of accessory parotid tumors

Accessory parotid gland tumors are defined as masses within salivary gland tissue located adjacent to Stensen's duct, but separate from the main body of the parotid gland. These tumors usually present as asymptomatic cheek masses. There is a temptation to excise these masses locally; however, the likelihood of injury to branches of the facial nerve is high. The best surgical approach to tumors in the accessory parotid region is via a standard parotid incision and concomitant superficial parotidectomy. Eight patients have been surgically treated with accessory parotid gland masses. Six patients had mixed tumors, one had a low grade mucoepidermoid carcinoma, and one had a localized parotitis. Our approach included a standard parotid incision, raising an anterior flap beyond the mass, and exposing the main trunk of the facial nerve, with careful tracing of all its branches. This approach to accessory parotid gland tumors is superior in that it provides a better margin of resection and minimizes functional and cosmetic deformities. Most importantly, there is less danger of injury to branches of the facial nerve.