Abstract
Since actinomycosis sometimes causes an abdominal tumor which mimics malignancy, treatment strategy varies from case to case. We herein report two cases which were treated with a combination of antibiotics and surgical intervention. Both patients presented with an intra-abdominal tumor lesion mimicking malignant disease after an appendectomy for acute appendicitis. Case 1 received surgical extirpation of the abdominal tumor in the liver and kidney twice since the clinical diagnosis of actinomycosis was not made. In contrast, case 2 was successfully treated by a combination of antibiotics and laparoscopic surgery following the experience of case 1. When a high probability diagnosis can be made, a laparoscopic approach is a useful and effective option to treat this condition.