Brain metastasis secondary to hepatoid adenocarcinoma of the lung

Abstract

Hepatoid adenocarcinoma (HAC) of the lung is a rare type of extrahepatic adenocarcinoma that is very similar in cellular morphology to hepatocellular carcinoma. HAC can be found in various organs within the peritoneal and retroperitoneal cavities, but is most commonly seen in the stomach, and least commonly in the lung. A review of the literature revealed only 29 previously documented cases of HAC of the lung. Of the 29 reported cases, only 2 of those patients had known brain metastases. This case report discusses the initial presentation, diagnostic data, treatment, and follow up of the thirtieth reported patient with HAC, and only the third with associated brain metastases. HAC of the lung can initially be mistaken for lung metastases from hepatocellular carcinoma. The molecular and genetic rearrangements of these tumors are of particular significance, as the particular expressions will vary based on the site of origin. As there is a scarcity in the available literature on this rare disease, it is imperative to utilize imaging, morphological, and immunohistochemical studies to aid in the diagnosis and treatment of HAC of the lung.