A 79-year-old woman was referred to our hospital on suspicion of esophageal cancer following an upper gastrointestinal endoscopy that revealed a protruding lesion in the middle esophagus. Upon reexamination at our hospital, a well-defined borderline protruding lesion with pale black deposits was observed starting from 24 cm from the incisors, surrounded by a black flat lesion. Additionally, black punctate lesions of varying sizes and shades were seen spreading within the lesion, strongly indicative of primary malignant melanoma of the esophagus (PMME). Histopathological examination confirmed tumor cell proliferation and melanin pigment deposition, primarily in the stratum basale. Immunostaining yielded positive results for S-100 protein and Melan-A, conclusively diagnosing PMME.
A CT scan revealed a 40-mm-sized lymph node enlargement in the gastroesophageal region. However, no distant metastasis was evident. Treatment was started with a combination of Nivolumab and Ipilimumab.
