Parotid Node Metastasis from Oral Mucosal Squamous Cell Carcinomas: a report of four cases

• Published in: Journal of Japanese Society of Oral Oncology Vol. 17; no. 1; pp. 1 - 11
• Main Authors: Okano, Tomohiro, Kimura, Yukinori, Hanazawa, Tomomi
• Format: Journal Article
• Language: Japanese
• Published: Japanese Society of Oral Oncology 2005
• Subjects: Imaging diagnosis; Metastasis; Oral mucosal cancer; Parotid node; Squamous cell carcinoma
• ISSN: 0915-5988; 1884-4995; 1884-4995
• DOI: 10.5843/jsot.17.1

The involvement of the parotid lymph node by metastatic squamous cell carcinoma of head and neck regions is not a common occurrence in comparison with its incidence of metastasis to the neck. The primary cancer zones at high risk of parotid lymph node metastases documented by some authors are the ear, eyelids, posterior cheek, and temporal and forehead scalp. Therefore, parotid lymph nodes may be overlooked as a potential site for metastases in patients with oral mucosal squamous cell carcinomas. Very few cases with parotid lymph node metastases from the oral cavity have been reported in the literature, and little information has been provided to define those patients who could be at high risk for developing parotid lymph node metastases. At our institute, between 1990 and 2003, four oral cancer patients with metastatic disease in the parotid gland were evaluated retrospectively. So, such cases were presented with CT images and the literature on this subject is reviewed with an emphasis on the anatomy of the parotid lymph nodes and lymphatic pathways. On CT images, the rim-enhancement and central low density of the lesions in the parotid gland could be useful findings for imaging diagnosis of the parotid node metastases. Only some parts of the oral cavity drain to the parotid lymph nodes according to anatomical studies, although, the literature survey suggested that metastases to the parotid lymph nodes could occur in malignancies of any sites of the oral cavity. From our experience and reviewing the literature, the parotid lymph nodes can also be associated with a neck dissection and/or radiotherapy for the upper cervical node metastasis. Therefore, when nodal diseases in the upper neck are detected on sectional images, the parotid region should be carefully examined for metastasis in the parotid lymph nodes, especially after the treatment. Oral squamous cell carcinoma involving intra-parotid lymph nodes metastases, although uncommon, remains of practical consideration in the follow-up studies.