case_images: PMC4986671_01
case_images: Endoscopic findings: proctoscopy revealed a mass at the anorectal junction.
case_images: ott-9-4969Fig1.jpg
case_images: PMC4986671_01_ott-9-4969Fig1.jpg
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case_images: Medical University. Colonoscopy showed a smooth mucosa with a polypoid bulge of ~1.0x0.8 cm in size, located 6 cm close to the anal verge, without any erosion, ulcer, hemorrhage, or necrosis (Figure 1). Microscopic examination showed diffusely distributed, small, and relatively uniform tumor cells with oval-shaped, deviated nuclei and deep staining (Figure 2A).
case_images: Hematoxylin and eosin immunohistochemical staining findings for the primary tumors are shown.. Notes: (A) Smaller tumor cells with a diffuse distribution are observed in the anal tumor; hematoxylin-eosin stain, x100. (B) High magnification microscopy showing a tumor cell morphology similar to that of plasma cells. The nuclei displayed atypia and conspicuous mitotic activity. (C) Tumor cells showing positive staining for S-100; immunohistochemistry staining, x100. (D) Tumor cells showing diffuse positive staining for vimentin; immunohistochemistry staining, x100.
case_images: ott-9-4969Fig2.jpg
case_images: PMC4986671_01_ott-9-4969Fig2.jpg
case_images: f2-ott-9-4969
case_images: Medical University. Colonoscopy showed a smooth mucosa with a polypoid bulge of ~1.0x0.8 cm in size, located 6 cm close to the anal verge, without any erosion, ulcer, hemorrhage, or necrosis (Figure 1). Microscopic examination showed diffusely distributed, small, and relatively uniform tumor cells with oval-shaped, deviated nuclei and deep staining (Figure 2A). The tumor cells resembled plasma cells, showing evidence of mitosis and less cytoplasm without clear pigmentation (Figure 2B). The results of the immunohistochemistry analyses performed using specific markers to confirm small-cell melanoma were as follows: cytokeratin (pan, -), synaptophysin (-), chromogranin A (-), CD20 (-), Pax-5 (-), CD3 (-), CDX2 (-), CD15 (-), S-100 (+; Figure 2C); vimentin (+; Figure 2D), HMB-45 (+), Melan-A (+), CD56 (+), CD138 (-), CD38 (-), MUM1 (-), and a Ki67 index of ~60%.
case_images: Breast ultrasonography images.. Notes: (A) A hypoechoic region sized 1.46x1.26 cm is seen in the outer upper quadrant of the left breast. (B) The mass has atypical characteristics and strip-shaped blood flow around the edges (BI-RADS 4C).. Abbreviation: BI-RADS, Breast Imaging Reporting and Data System.
case_images: ott-9-4969Fig3.jpg
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case_images: Breast ultrasonography showed a hypoechoic region in the outer upper quadrant of the left breast sized 1.46x1.26 cm2 (Figure 3A). The mass had atypical characteristics and strip-shaped blood flow around the edges (Breast Imaging Reporting and Data System 4C; Figure 3B).
case_images: Immunohistochemical staining findings for the metastatic tumors are shown.. Notes: (A) Metastatic tumor in the left breast showing morphological findings consistent with those of the anorectal melanoma; immunohistochemistry staining, x100. (B) Metastatic tumor cells showing positive staining for vimentin; immunohistochemistry staining, x100. (C) Metastatic tumor cells showing positive staining for Melan-A; immunohistochemistry staining, x100. (D) Metastatic tumor cells showing positive staining for Hmb45; immunohistochemistry staining, x100. Scale bar, 100 mum.
case_images: ott-9-4969Fig4.jpg
case_images: PMC4986671_01_ott-9-4969Fig4.jpg
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case_images: The pathological examination of the specimen obtained via fine needle aspiration biopsy using a hollow needle showed morphological findings consistent with anorectal melanoma (Figure 4A). The immunohistochemistry results were as follows: cytokeratin (pan, -), vimentin (+; Figure 4B); S-100 (+), Melan-A (+; Figure 4C); HMB-45 (+; Figure 4D); CD3 (T lymphocytes, +), CD20 (B lymphocytes, +), Pax-5 (B lymphocytes, +), chromogranin A (-), synaptophysin (-), CD138 (-), ER (-), Her2 (-), P63 (-), GATA-3 (-), and a Ki67 index of ~70%, which confirmed anorectal melanoma metastatic to the breast.