The Origin of Liver Metastatic Adenocarcinomas, a Single Center Experience from the South of Iran

Background: Liver is one the most common sites of metastasis, and metastatic liver cancers are the most common liver malignancies. Metastatic adenocarcinomas are the most common metastatic liver cancers, which have different origins. The liver biopsy is a very important step to find the origin of metastatic cancer by immunohistochemistry. Objectives: In this study, we aimed to find the primary origin of metastatic adenocarcinomas in the liver biopsies. Methods: In this study, 210 liver biopsies with the primary diagnosis of metastasis with unknown origin in the liver were investigated from 2008 to 2017 that 126 cases (60%) of which have proved to bemetastatic adenocarcinoma with unknown origin. Histologic studies and immunohistochemical (IHC) stains were performed. Also, a complete endoscopic, radiologic, clinical, and paraclinical studies were carried out besides the liver biopsy to find the origin of the adenocarcinoma. Results: Among these 126 liver biopsies, the origin of 94 cases (74.6%) was definitely determined by IHC and other examinations mentioned above. All efforts for thirty-two cases (25.4%) failed to find the primary origin despite a complete examination. Most common primary origins were colon (23.8%), lung (19%), pancreas (13.9%), and breast (11.2%). Conclusions: Performing a liver biopsy is a very helpful modality to find the origin of liver metastatic adenocarcinoma but needs to be combined with other clinical findings and diagnostic modalities to find the origin of metastasis to the liver. By combining these methods, our study showed that the origin of 74.6% of metastatic liver adenocarcinomas can be found, which is most commonly from colon, lung, and pancreas.