Esophageal Melanocytosis

Abstract

Esophageal melanocytosis is a rare entity defined by the proliferation of a melanocytic basal layer of the esophageal squamous lining and deposition of melanin in the esophageal mucosa. Esophageal melanocytosis is considered a benign entity of unknown etiology; however, it has been reported as a melanoma precursor. We report a case of esophageal melanocytosis in a diabetic and hypertensive 67-year-old male with recurrent dizziness and syncope for the past 6 months. Given his complaint of dyspepsia, he underwent an upper gastrointestinal endoscopy, in which an esophageal biopsy revealed the diagnosis of esophageal melanocytosis. The definitive diagnosis of esophageal melanocytosis can only be made by histological analysis. The histologic differential diagnoses include melanocytic nevi and malignant melanoma. Therefore, they need to be ruled out.

Keywords: Endoscopy, Gastrointestinal; Esophageal Mucosa; Esophagus; Gastroesophageal Reflux; Melanins.

Figure 1. Photomicrograph of the upper gastrointestinal tract endoscopy shows darkly pigmented, flat irregular lesions.

Figure 2. Photomicrograph from gastroesophageal junction biopsy shows in A – Gastric mucosal glands and hyperplastic stratified squamous epithelium. The basal layer of squamous epithelium shows an increased number of pigment-laden dendritic melanocytes and an increased quantity of melanin pigment (H&E x200); B and C – These intraepithelial melanocytes are immunopositive for HMB45 and S100, respectively (B x400; C x200); D – Special stain for melanin bleach using hydrogen peroxide shows completely bleached melanin pigment.