Well-differentiated papillary mesothelioma manifesting in a hernia sac.

Well-differentiated papillary mesothelioma (WDPM) is a tumor of uncertain malignant potential that usually occurs as a multifocal lesion of the female peritoneum, and is incidentally found at the time of surgery. We present here a multifocal case that had arisen from the lining of a hernia sac. To our knowledge, only four cases of this event have been previously described. A review of the five cases reported, including our case, revealed that the mean age of the patients was 56.6±8.35 years. There was predominance in men (4:1). In four cases, the lesion was incidental. Most tumors were found in inguinal hernias. Four cases presented with gross abnormalities in the hernia sac. All the five patients were alive with no evidence of WDPM after a mean follow-up of 38.6 months. Extensive sampling of this rare lesion helps to rule out an epithelial malignant mesothelioma and prevents overtreatment.