[Transformation of hepatic adenoma into hepatocellular carcinoma in patients with prolonged use of oral contraceptives] Transformacao de adenoma hepatico em carcinoma hepatocelular em pacientes com uso prolongado de contraceptivo oral.
Two cases of hepatic cell adenoma associated with hepatocellular carcinoma in long-term oral contraceptive (OC) users are described. Hepatic cell adenomas are rare benign tumors whose incidence has increased with the use of OCs. They generally occur in women over age 30 who have used OCs for five years or longer. The preferred treatment is currently hepatic resection, which reduces the risk of intraperitoneal hemorrhage leading to death. A 30-year-old woman with a history of 15 years of OC use and a 37-year-old woman with a history of 20 years of OC use underwent diagnostic procedures followed by laparotomy and resection of hepatic cell adenomas. Histologic examination in both cases revealed hepatic cell adenoma with areas of hepatocellular carcinoma in a liver with otherwise normal parenchyma. Although the causal relationship between OC use and hepatic cell adenoma is well accepted, a similar etiologic relationship between OCs and hepatocellular carcinoma has not been definitively established despite anecdotal evidence and some suggestive epidemiological data. Relatively few well documented cases of malignant transformation of hepatic cell adenoma have been published. Many authors believe that hepatic cell adenomas induced by OC use are potentially premalignant, but the mechanism through which the transformation might occur has not been explained. It is likely that nonspecific pharmacological actions as well as actions mediated by hormonal receptors are involved.