Two cases of spontaneous regression of multicentric hepatocellular carcinoma after intraperitoneal rupture: possible role of immune mechanisms.

We report two cases of spontaneous regression of hepatocellular carcinoma. Firstly, a 64-year-old man with alcohol related cirrhosis developed multiple liver tumours with elevation of the alpha-fetoprotein level at 915 ng/ml. A spontaneous regression of all the tumoural masses but one and normalization of the alpha-fetoprotein level was observed after intraperitoneal spread of the malignancy. Resection of the remaining tumour 9 months later confirmed a hepatocellular carcinoma. Secondly, a 70-year-old woman with alcohol related cirrhosis developed multiple liver tumours with elevation of the alpha-fetoprotein level to 4000 ng/ml; a regression of all the tumoural masses but one and a decrease of the alpha-fetoprotein level to 400 ng/ml was observed after intraperitoneal spread of the malignancy and treatment with tamoxifen. We discuss a possible immune mechanism of tumoural regression with a review of similar cases described in the literature.