Malignant melanoma of the prostate: Primary or metastasis? A case report

Figure 1 Compressed bone of thoracic 12 vertebrae showing a high T1 signal and low T2 signal.

Figure 2 Bone single photon emission tomography/computed tomography showing T12 compression of the whole body bone, and the concentration of radioactivity in bilateral ribs, thus bone metastasis was considered.

Figure 3 ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography showing focal glucose metabolism in the left lobe of the prostate, and a malignant tumor waiting to be excreted.

Figure 4 Histopathology. A: Prostate adenocarcinoma [Hematoxylin and eosin (HE), original magnification, 25 ×]; B: Small foci of melanocytes in the proliferative prostate tissue (HE, original magnification, 25 ×); C: Immunohistochemical results: HMB45⁺ (HE, original magnification, 25 ×).

Figure 5 Gastroscopy findings. A: Multiple mucosal black spots in the body and fundus of the stomach; B: Microscopic small foci of melanocytes in the gastric mucosa (hematoxylin-eosin, original magnification, 25 ×).