Implantational growth of adenocarcinoma after Kraske operation for rectal tubular adenoma.

A 55-year-old man underwent an operation for a rectal tubular adenoma 1.5 cm in diameter by posterior proctotomy (Kraske operation). Later two rectal tubular adenomas were excised by electrocoagulation. Eight years after the primary operation, a 12 x 8 x 5 cm large mucinous adenocarcinoma was discovered inside the gluteus maximus muscle extending under the subcutaneous region of the primary incisional scar. No other metastases could be detected. It is probable that implantation of malignant or potentially malignant cells during the first operation was responsible for the adenocarcinoma.