Epithelial-Myoepithelial Carcinoma of the Parotid Gland: A Case Report

PURPOSE: Epithelial-myoepithelial carcinoma (EMC) represents about the 1% of the malignant neoplasms in the salivary glands and clinically most commonly found localized, well defined and sometimes presents orofacial pain. Treatment of choice is surgical excision. Postoperative radiotherapy can be used when surgical margins are doubtful. We report our experience of EMC of the parotid gland. METHODS: A 78-year-old man presented with a three-year history of a localized, painless, 7 x 6 cm sized recurred tumor in his right preauricular area. He was diagnosed as EMC of the right parotid gland. So a total parotidectomy was performed. In his old medical history, he had a mass in the same area 5 years ago. The diagnosis of pleomorphic adenoma was made and the mass excision was performed at the local clinic without further evaluation. RESULTS: It was unable to visually discriminate between the tumor and the normal tissue. So a total parotidectomy was performed. The patient was got post-operative radiotherapy and was followed up for 9 months. There was no specific evidence of recurrence. CONCLUSION: We present a case of EMC of the parotid gland in right preauricular area, which is uncommon. So we report a uncommon case of EMC to discuss about our experience with relevant journal discussion.

A Case of Epithelial-myoepithelial Carcinoma of the Parotid Gland

Epithelial-myoepithelial carcinoma (EMC) of the salivary gland is a rare tumor that comprises approximately 1% of all salivary gland tumors. It has a distinctive histological appearance comprising ductal structures with an inner epithelial cell component and an outer layer of myoepithelial cells. We report a case of EMC of the parotid gland in a 41- year-old man. He presented left-sided subauricular swelling developed 3-month earlier. Neck CT scans revealed a well-defined mass in the left superficial parotid gland. He underwent superficial parotidectomy and was diagnosed as EMC. He was taken postoperative radiotherapy. There was no evidence of recurrence during a follow-up period of 12 months.

Epithelial-Myoepithelial Carcinoma of the Salivary Glands: Clinical Aspects and Treatment Outcome / 대한이비인후과학회지

BACKGROUND: The epithelial-myoepithelial carcinoma(EMC) of major and minor salivary glands is a low grade malignancy which shows frequent local recurrence. OBJECTIVES: The aim of this study was to define the clinical feature and treatment outcome of EMC of major and minor salivary glands. MATERIALS AND METHODS: Nine cases of EMC of major and minor salivary glands were reviewed retrospectively. RESULTS: The clinical course varied from slowly growing painless mass to the mass associated with facial nerve paralysis, bleeding or bone desutruction. Local recurrence was observed in 3 cases(33%) at 3, 10 and 11 months after primary resection, but no metastasis to periglandular, cervical lymph nodes or distant site occurred in our series including three recurrences. One of three recurrent patients died due to local extension of the tumor. Other two patients with recurrent tumors were successfully treated with revision operation and survived more than 2, 6 years without disease, respectively so far. Preoperatively these tumors were usually regarded as benign salivary gland tumor in CT scan except for the cases showing bone destruction. Atypical cells on fine needle aspiration cytology/frozen biopsy coupled with benign looking CT finding suggested low grade malignancy in which case EMC should be considered a differential diagnosis. Pathologic diagnosis was frequently confused with other high grade carcinoma rather than low grade carcinoma or benign tumor. This resulted in unnecessary postoperative radiotherapy, but clinically aggressive recurrent cases recurred despite radiotherapy. No malignant cells were found in clinically enlarged lymph nodes, and we have to retain positve attitude toward surgical management of advanced or recurrent EMC keeping in mind that recurrent tumor may inherit different tumor bilogy. CONCLUSION: Although epithelial-myoepithelial carcinoma is a rare salivary gland tumor, otolaryngologists should be aware of its existence because this low grade malignancy can cause diagnostic confusion during workup and also frequently be misdiagnosed as other high grade salivary malignancy in clinically aggressive form.