Diagnosis and surgical outcomes for primary malignant melanoma of the esophagus: a single-center experience.

Background: We summarize the experience of diagnosis and surgical therapy for primary malignant melanoma of the esophagus (PMME).

Methods: Clinical data of 13 patients diagnosed as having PMME treated by surgery as their primary therapy from 2000 to 2012 were retrospectively analyzed, and survival information was collected through follow-up.

Results: The average age (±standard deviation) of participants in this study was 66.4±7.6 years, and 84.6% were male. Overall, 61.5% of tumors were located in the lower thoracic esophagus. The accuracies of clinical T stage, N stage, and TNM stage were 53.9%, 46.2%, and 38.5%, respectively, compared with pathological staging (kappa=0.252, p=0.023). Surgical mortality and morbidity were 7.7% and 53.9%, respectively. The incidence of lymph node metastasis for patients with tumor invading within the mucosa was 0, but increased to 42.9% (3 of 7) with tumor invading to the submucosal layer. Primary malignant melanoma of the esophagus in the mid third of the thoracic esophagus had a greater chance to metastasize to perigastric lymph nodes (2 of 5) than to middle mediastinal lymph nodes (1 of 5). For PMME located at the lower third of the thoracic esophagus, upper mediastinal lymph node metastasis was more likely to occur (2 of 4) with tumor invasion penetrating the proper muscle layer. Recurrence occurred within 1 year in all patients with tumor later than Stage Ib. The most common recurrent organ was the liver. The overall 1-year and 5-year postoperative survival rates were 54.0% and 35.9%, respectively, and lymph node metastasis was the independent predictive factor for postoperative survival (p=0.013; odds ratio, 15.05).

Conclusions: Despite the similarity in lymph node metastatic patterns to squamous cell carcinoma, PMME is more inclined to distant metastasis. Clinical staging was inconsistent with pathological staging for PMME based on endoscopy and computed tomography. Surgical therapy was the optimal treatment for PMME at an earlier stage. Early diagnosis and aggressive lymph node dissection were beneficial for accurate staging, potentially reducing recurrence and thus improving survival.