A case of gallbladder metastasis from nasal mucosal melanoma with noteworthy endoscopic ultrasonography findings

See PDF.] a Transabdominal B-mode ultrasonography (US) showed a 22 × 12-mm polypoid lesion. b Transabdominal color Doppler US revealed a spotty flow signal in the mass. c B-mode endoscopic US (EUS) showed a pedunculated heterogeneous mass. d Color Doppler (eFLOW) EUS revealed linear vessels with branches running from the stalk to the interior. e Relatively strong contrast effect on early phase of contrast-enhanced computed tomography (CECT) (arrowheads). f Prolonged contrast effect on delayed phase of CECT (arrowheads). g Isointensity on T1-weighted image of magnetic resonance imaging (MRI) (arrowheads). h Isointensity on T2-weighted image of MRI. i, j Gross appearance of the resected gallbladder showed a black polypoid lesion in the neck portion. k Loupe imaging showed that the tumor was contained in the lamina propria without invasion into the muscle layer. l Photomicrograph showed proliferation of atypical round cells with abundant melanin pigments [hematoxylin–eosin stain, × 200]. m Immunohistochemical positivity of the tumor cells for SOX10 [× 10] Macroscopic findings described a black polypoid lesion localized in the neck of the gallbladder (Fig. 1i, j). Tumor cells were positive for HMB45, Melan A, and SOX10 on immunohistochemical staining (Fig. 1m). Because gallbladder metastases from melanoma are rare, characteristics of the sonographic findings have not been fully established [1, 2]. Declarations Conflict of interest The authors declare no conflicts of interest.