Primary malignant melanoma of the esophagus arising from melanocytosis: a case report and literature review.

Primary malignant melanoma of the esophagus (PMME), a rare histologic type of esophageal cancer, accounts for 0.1-0.8% of all primary esophageal tumors. Esophagectomy is the main treatment in the absence of distant metastasis. Black lesions in esophageal mucosa (melanosis) and presence of melanocytes in biopsy specimen (melanocytosis) may be precancerous but have rarely been demonstrated to be associated with PMME so far. Here, we present a case of PMME arising from melanocytosis during follow-up, and conduct a literature review of cases in which PMME developed during the follow-up of melanosis. A 79-year-old woman underwent esophagogastroduodenoscopy, which revealed a black pigmented lesion in the esophagus. Biopsy results revealed melanocytes without atypia, indicating melanocytosis. One-year follow-up revealed that the lesion had enlarged, and she was referred to our hospital. Further evaluation confirmed the diagnosis of malignant melanoma without metastasis. Thoracoscopic esophagectomy was performed, and retrosternal reconstruction was made with a gastric conduit. The histopathologic evaluation confirmed PMME. The patient experienced minor postoperative anastomotic leakage but recovered with conservative treatment. No recurrence was detected at last follow-up 2 years after surgery.