Pulmonary Embolus of Benign Liver Tissue Following Partial Hepatectomy

We report the case of a 55-year-old man with metastatic well-differentiated neuroendocrine tumor involving the liver and lung. He underwent a left hepatectomy to resect a large mass in the liver followed by a right lung lower lobectomy 4 months later to resect a smaller mass in the lung. The histologic evaluation of the lung specimen revealed a 0.1-cm nodule of ectopic benign liver tissue within a lumen of a small pulmonary artery. Histochemical and immunohistochemical stains were consistent with benign liver and did not provide support for metastatic well-differentiated hepatocellular carcinoma. To our knowledge, this is the first documented case of pulmonary arterial embolization by benign liver tissue as a complication of hepatectomy.