Primary gastric melanoma: A case report with imaging findings and 5-year follow-up

Figure 1 Digital gastrointestinal radiography showed that the tumor was located in the gastric cardia. Thickening and rigidity of the gastric wall with no peristalsis were detected.

Figure 2 Computed tomography images. A: Computed tomography plain scanning revealed an iso-or slight low-density tumor; B: The tumor showed heterogeneous enhancement in the arterial phase; C: Persistent enhancement was found in the portal vein phase.

Figure 3 Magnetic resonance imaging images. A: On magnetic resonance imaging (MRI), the mass exhibited a heterogeneous hyperintensity on T1-weighted imaging; B: On MRI, the mass exhibited a heterogeneous hypointensity on T2-weighted imaging; C: Diffusion weighted imaging showed hyperintense signal; D: On enhanced image, the lesion was obviously unevenly enhanced.

Figure 4 Histological and immunohistochemical images. A: Hematoxylin and eosin staining (× 100) showed that the tumor cells were lymphocyte-like with pigmentation; B-D: Immunohistochemical staining showed that the primary gastric melanoma (PGM) was positive for HMB-45 (B; × 100), S100 (C; × 400), and MITF (D; × 100).

Figure 5 Re-examination 36 mo after total gastrectomy. Computed tomography revealed that no recurrence or metastasis was observed. Surgical sutures were seen (arrow).