Fig. 1

a, b There was a polypoid lesion with redness on the left back. c Lesions were present from the dermis to the subcutaneous fatty tissue. d Necrosis was found in a wide area of the lesion. e Columnar epithelial cells formed a fused ductal structure. There were also ducts that produce mucus in the lumen (hematoxylin–eosin staining, c × loupe. d ×20 magnification. e ×200 magnification)