case_images: PMC7566174_01
case_images: Hard fixed 8 x 6 x 5 cm left inguinal mass and overlying skin at a pre-ulcer stage.
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case_images: The overlying skin was at a pre-ulcer stage (Figure 1).
case_images: Computed tomography (CT) scan with contrast shows a 12 x 11 x 5 cm multilobular
  () mass of the left
  inguinal region with heterogeneous enhancement.
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case_images: Pathologic inguinal lymph nodes and infracentimetric subcutaneous nodules were observed (Figure 2).
case_images: (A) Wide local excision of the tumor () with peripheral margins of 2 cm. (B)
  Wide local excision with deep margins extending to the level of the deep fascia and an
  intact left femoral pedicle ( ).
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case_images: MCC. The patient underwent a left inguinal dissection with wide local excision of the tumor with 2 cm margins and satellite lymph node dissection (Figure 3A and B). Macroscopic examination revealed a solid, yellow-tanned, and lobulated mass measuring 13 x 10.5 x 9.5 cm with clear lateral margins of 1 cm and narrow deep margins (<4 mm).
case_images: (A) Merkel cell carcinoma infiltrating subcutaneous fatty tissue (hematoxylin-eosin,
  original magnification x200). (B) Small round cells with a round nucleus, dusty
  chromatin, and numerous mitotic figures ( ) (hematoxylin-eosin, original magnification
  x400). (C) Para nuclear dot-like staining with cytokeratin 20 (immunoperoxidase
  staining, original magnification x400). (D) Cytoplasmic staining with synaptophysin
  (immunoperoxidase staining, original magnification x400).
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case_images: Histological examination revealed a dermal and subcutaneous tumor with a diffuse growth pattern (Figure 4A). Frequent mitotic figures were observed (Figure 4B). Immunohistochemically, tumor cells were positive for cytokeratin 20 (CK20) in a perinuclear dot-like fashion (Figure 4C), chromogranin, and synaptophysin (Figure 4D).