Primary malignant melanoma of the gastroesophageal junction with plasmacytoid features and reactivity to cd138: A case report and review

Melanoma of mucosal sites is rare and is extremely rare in esophagus. Melanoma is known for its histological diversity mimicking any other malignancies with poor prognosis. Clinical presentation may be similar to other gastroesophageal junction malignancies with obstructive symptoms/bleeding with pigmented polypoid mass on endoscopy and gross examination. However, metastasis from elsewhere is to be considered in the absence of melanocytosis in the adjacent squamous epithelium. Immunohistochemistry with a panel of markers is necessary in amelanotic lesions, poorly differentiated morphology, and small biopsy specimens. We report a case of melanoma with plasmacytoid features in the gastroesophageal junction diagnosed in a small biopsy with immunohistochemical findings and follow-up esophagogastrectomy.