A Retrospective Study of Malignant Parotid Tumors

• Published in: Nippon Jibi Inkoka Gakkai Kaiho Vol. 109; no. 2; pp. 103 - 111
• Main Authors: Sakamoto, Kikuo, Chijiwa, Hideki, Miyajima, Yoshimi, Umeno, Hirohito, Nakashima, Tadashi
• Format: Journal Article
• Language: English; Japanese
• Published: Japan The Oto-Rhino-Laryngological Society of Japan, Inc 2006
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; carcinoma of the parotid gland; Child; facial palsy; Facial Paralysis - etiology; Female; histopathological finding; Humans; Male; Middle Aged; Neoplasm Recurrence, Local; Parotid Neoplasms - mortality; Parotid Neoplasms - pathology; Parotid Neoplasms - surgery; Retrospective Studies; treatment modality; Treatment Outcome
• ISSN: 0030-6622; 1883-0854
• DOI: 10.3950/jibiinkoka.109.103

The clinical features of 74 patients (39 men, 35 women; mean age, 62 years) with malignant parotid tumors were retrospectively investigated. According to the TNM Classification, 4 patients were classified as T1, 9 as T2, 6 as T3, and 55 as T4. Fifty cases were staged as N0, 9 as N1, 14 as N2 and 1 as N3. Tumors located in both lobes of the parotid gland were the most frequent type of tumor (49%). Twenty-four percent of the 74 patients exhibited facial nerve palsy before treatment. Facial palsy was found predominantly in cases with a higher T classification or with deep lobe occupation. Histopathologically, sixteen tumor types were observed; mucoepidermoid carcinoma was the most common. The overall five-year and ten-year survival rates determined using the Kaplan-Meier method were 65% and 61%. The factors influencing a poor outcome were T4 classification (p=0.0189), an N+stage (p<0.0001), and facial palsy (p<0.0001). As for the major histopathologic types, the five-year survival rates were 69% for mucoepidermoid carcinoma, 48% for adenocarcinoma, 71% for adenoid cystic carcinoma, and 100% for acinic cell carcinoma and malignant mixed tumor. With respect to the treatment modality, patients who were classified as T1 or T2 and whose tumors were located in the superficial lobe without facial nerve invasion could be satisfactorily treated with only a superficial lobectomy conserving the facial nerve. A total parotidectomy with total removal of the facial nerve seemed necessary for T3 and T4 cases, especially those with adenocarcinoma or mucoepidermoid carcinoma. Modified neck dissection may be necessary for N0 cases, especially those with adenocarcinoma, adenoid cystic carcinoma or undifferentiated carcinoma. Nerve grafting after total nerve resection is recommended for a better quality of life.