Skin Metastasis of Gastric Carcinoma in a Patient with a Widespread Subcutaneous Induration of the Abdominal Wall

We report the case of a 74-year-old man with widespread subcutaneous induration of the abdominal wall who had undergone a total gastrectomy 8 months before examination at our hospital. A histologic examination of a skin biopsy specimen revealed an infiltration of atypical carcinoma cells, including signet ring cells, from the dermis through subcutaneous tissue. Hyperplasia of the collagen fibers was also observed in the dermis, but there were no carcinomatous emboli in the dermal lymphatic vessels. The images of an abdominal CT scan suggested the presence of massive peritonitis carcinomatosa without any signs of lymphadenopathy or hepatic metastasis. Metastasis was thus thought to have occurred due to a direct invasion from the widespread peritonitis carcinomatosa.