Primary hepatocellular carcinoma is divided into two main categories: hepatocellular carcinoma and intrahepatic cholangiocarcinoma.
Pathologic histologic staging of hepatocellular carcinoma
The tumor cells of hepatocellular carcinoma often resemble normal hepatocytes and are characterized by an interstitial stroma consisting of blood sinusoidal-like lacunae lined with a single layer of endothelial cells.
Histologic types commonly include fine-beam, coarse-beam, pseudoglandular ductal, and doughnut types, with specific types such as clear cell, lipid-rich, spindle cell, and undifferentiated.
Beam type
Tumor cells are arranged in strips of varying widths, mostly in highly and moderately differentiated hepatocellular carcinoma. Highly differentiated carcinomas have a thin beam-like structure, while the trabeculae widen in intermediate differentiation.
Pseudoglandular ductal type
Made up of a single layer of tumor cells that surrounds into an adenoid or glandular vesicle-like structure. Highly differentiated carcinomas have smaller adenoid structures than moderately differentiated carcinomas.
Granular lamellar type
The blood sinus-like lumen is not obvious and the tumor has a solid appearance, mostly seen in poorly differentiated carcinomas.
Special types
Including fibrous lamellar carcinoma, cirrhotic hepatocellular carcinoma, undifferentiated carcinoma, lymphoepithelioma-like carcinoma, and sarcomatoid hepatocellular carcinoma.
Pathologic histologic staging of intrahepatic cholangiocarcinoma
Intrahepatic cholangiocarcinoma is most commonly adenocarcinoma with fibrous interstitial reaction and can also present with a variety of histologically and cytologically specific types.
Rarely seen specific types include adenosquamous and squamous carcinomas, mucinous carcinomas, indolent cell carcinomas, clear cell carcinomas, mucinous epidermoid carcinomas, lymphoepithelioma-like carcinomas, and sarcomatoid carcinomas.
Frequently asked questions about pathologic staging of hepatocellular carcinoma
Frequently asked questions about the pathologic staging of hepatocellular carcinoma are answered below.
Does the pathologic histologic staging of hepatocellular carcinoma stand alone?
No, different areas of the same tumor can present with different histologic staging.
Can the pathologic histologic staging of hepatocellular carcinoma and intrahepatic cholangiocarcinoma coexist?
Yes, primary liver cancer also includes mixed hepatocellular carcinoma-cholangiocarcinoma, in which the same tumor has both areas of hepatocellular carcinoma and areas of cholangiocarcinoma.
Is the prognosis for the specific type of cancer worse than the common type?
Is the prognosis for the specific type of cancer worse than the common type?
Not necessarily. For example, fibrous lamellar carcinoma, which occurs mainly in adolescents, has a prognosis similar to but better than typical hepatocellular carcinoma in a noncirrhotic setting.
What are lymphoepithelioma-like carcinoma and sarcomatoid carcinoma?
Lymphoepithelioma-like carcinoma is a tumor with a large number of lymphocytes between the tumor cells, and some tumors contain EBV-positive tumor cells. Sarcomatoid carcinoma refers to areas containing focal malignant spindle cells and focal cancer-like areas.
How to distinguish the fine beam type from the coarse beam type of hepatocellular carcinoma?
How do you distinguish between the fine beam type and the thick beam type of hepatocellular carcinoma?
Fine beam type refers to two or three layers of tumor cells forming a striated structure; thick beam type refers to greater than three layers of tumor cells forming a striated structure.