Primary Malignant Melanoma of the Lip: A Report of 48 Cases

Lip melanoma (LM) is a rare malignant tumor and well-established treatment protocols for it are in short supply. The objective of this study was to evaluate the outcome of treatment modalities and explore the prognostic factors.

A retrospective chart review was performed on 48 patients with primary LM treated in the authors' hospital from January 1992 to November 2013. The clinical characteristics and treatment modalities were identified and correlated with the outcomes.

The 5-year overall survival (OS) rate was 56.1%, and the rate of cervical lymph node (CLN) metastasis was 46% (22 of 48). A tumor of at least 4 cm (P = .001), nodular types (P = .003), and CLN (P < .0001) were independent prognostic factors for OS. Twenty-five patients died during follow-up, mainly from to neck recurrence (14 of 25). Chemotherapy significantly improved the 5-year OS rate in patients with stage IV LM (P = .03), but not in those with stage III (P = .8).

LM has a lower CLN and distant metastasis rate and a better prognosis than other oral mucosal melanomas. A long history of melanin pigmentation is a dangerous sign for all patients, and smoking seems to be associated with LM in male patients. Tumor size (≥4 cm), nodular type, and CLN positivity are poor prognostic factors. A wide excision with close observation is advocated as the primary treatment for stage III LM. Adjuvant chemotherapy is useful for patients with stage IV cancer, but not for those with stage III.