Native Hepatectomy Specimens
Access to the entire liver will result in significant additions or changes to the original diagnosis in about 10% of cases. One of the most frequent additions is the discovery of a small hepatocellular carcinoma(s), especially in patients with chronic viral hepatitis type B and/or C as the underlying liver disease. Other common changes include abnormalities of the hilar or peri-hilar bile ducts and their accessory glands; the detection of unsuspected a-1-anti-trypsin deficiency; infarcted regenerative nodules and minor developmental abnormalities of the intra-hepatic biliary tree.
The gross and histopathologic examination of native hepatectomy specimens should be completed according to a defined protocol(Figure 1), which represents considerations of excellent patient care and research needs(1). The liver is first examined from the capsular surface and obvious defects are sampled. The hepatic artery, portal vein and bile duct are identified and opened longitudinally and the resection margins of each are routinely sampled. Any obvious pathologic defects, including thrombi, vegetations, areas of strictures or mural fibrosis, papillae or tumors are also sampled. The precise location of any stents, drainage tubes, stones or other objects is also noted. The hepatic veins and inferior vena cava, if present, are examined next and the resection margins sampled. Then, the gallbladder, if present, is opened and any obvious defects are sampled. In the absence of defects, a section from the fundus and another from the region of the neck and cystic duct are routinely submitted in one cassette.
Once the liver has been thoroughly examined from the exterior surface, it is extremely important to thinly slice the liver at 1 cm intervals. This is needed so that small tumors or defects are not missed. We prefer to horizontally align the plane of sectioning similar to that observed in computerized tomograms and other scans of the liver. Therefore, the radiographic hepatic images and slices of the resected liver can be directly compared. It is also very important to liberally sample regenerative nodules that, by virtue of size, color and/or consistency, are distinguished from the surrounding parenchyma. Sampling of other intrahepatic defects, such as tumors, cysts, abscesses or other lesions is intuitive. Microscopic sections other than from suspicious nodules or other obvious defects should be taken according to a predefined protocol. We routinely take a subcapsular and deep section of the right and left lobes; the resection margins of the hepatic artery, bile duct and portal vein submitted together in one cassette; the deep hilum; and the resection margins from the hepatic veins/vena cava.
The precise location of any obvious defects should be recorded on a diagram and we routinely capture digital images of important findings. Bulk frozen, optimum cold temperature compound embedded, and bulk formalin-fixed tissue are saved from each case. Since native hepatectomy specimens often first become available for examination between midnight and 6 AM, arrangements often have to be made for research request that require isolation of viable cells, mRNA or tissue enzymes susceptible to degradation. These requests are best handled between the department of pathology and the investigators on a cases by case basis. Priority must be given to diagnostic and patient management considerations with research concerns of secondary importance. However, the two are rarely in conflict and in most cases, both can be simultaneously fulfilled.