Histopathologic analysis of the nodule revealed a cystlike cavity in the dermis, with multiple villous or papillary structures protruding into the cavity. Fibrin, mucin, and erythrocytes were also seen within the cavity. The papillary structures were covered by a synoviumlike lining. A tracklike defect was found at the bottom of the cyst (not shown), probably corresponding to the site where the wire was pulled away from the cyst. Away from the main lesion, there was a localized area of degenerated collagen as well as partial necrosis of the blood vessels.
A Dermal Nodule Near a Laparotomy Scar—Diagnosis. Arch Dermatol. 2006;142(6):775-780. doi:10.1001/archderm.142.6.775-h