Advanced primary amelanotic malignant melanoma of the esophagus: A case report

Figure 1 Upper gastrointestinal radiography. A: Mucosa film, with a polypoid intraluminal mass (arrow) present in the lower esophagus; B: Full-filling film, with a polypoid filling defect (arrow), without obstruction, is shown.

Figure 2 Upper gastrointestinal endoscopy. A nonpigmented polypoid mass protruded into the esophageal lumen, located 30-35 cm from the incisors. The mass extended along the esophageal longitudinal axis.

Figure 3 Imaging examinations. A: Computed tomography image showing the bone metastasis, with a nodular and osteogenic bone destruction area (arrow) present in the left iliac bone; B: Single-photon emission computed tomography image showing a slightly hypermetabolic site (arrow) in the left iliac bone; C: Single-photon emission computed tomography-computed tomography fusion image showing a hypermetabolic area, with bone destruction (arrow).

Figure 4 Thoracic contrast-enhanced computed tomography. An enhancing mass (arrow) was present in the lower esophagus.

Figure 5 Histopathology (hematoxylin-eosin staining). A: The tumor cells are shown to have formed nests, without melanin granules; B: Polymorphic tumor cells with atypical and hyperchromatic nuclei are shown.

Figure 6 Immunohistochemical staining. The biopsy stained positive for S100 (A), HMB45 (B), melan-A (C), and Ki67 (D) but was negative for CK (E).