Table 7-21.
Hepatic tumors
| CK7 | CK20 | AE1/AE3 | CAM 5.2 | KERATIN HMW | CEA m | CEA p | TTF-1 | HEP | AFP | CD10 | CHROM | MUCI | BILE | CIRRHOSIS | HBV | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hepatocellular carcinoma (HCC) | Low | neg | Low | POS | neg | neg | Higha | Highb (cyt) | High | Mod | Higha | neg | rare | May be present | 65–90% | 50% |
| Hepatoblastoma | Low | POS | Low | Higha | POS | High | Low | absent | rare | |||||||
| HCC:fibrolamellar | Mod ? | neg | POS a | POS | neg ? | neg | May be present | absent | rare | |||||||
| Cholangiocarcinoma | POS | Mod | POS | POS | High | High | POS | neg | neg | neg | neg | 75–100 | neg | rare | rare | |
| Metastatic carcinoid tumor | Low | Low | High | POS | Mod | Mod | Lowc (nuc) | neg | Low | POS | neg | absent | absent | |||
Sinusoids of HCC show diffuse CD34 positivity in 80% to 90% of cases, but this is not seen in normal liver. CD34 positivity can also be seen in focal nodular hyperplasia. Metastatic carcinomas can show diffuse positivity in 20% of cases, but the positive endothelial cells are present throughout the tumor and the cells do not surround nests of tumor cells, as is seen in HCC.
Reticulin stains can be helpful in the evaluation of fine needle aspirates or core needle biopsies of liver lesions. HCC has an a bnormal pattern of absent, decreased, or expanded trabecula, whereas benign lesions show a normal trabecular pattern.
Metastatic carcinomas can usually be distinguished from HCC by frequent expression of CK7, only rare expression of HepPar1, the absence of a bile canalicular pattern for CEA p and CD10, and the absence of cytoplasmic positivity for TTF-1.
Metastatic carcinomas to the liver often cannot be reliably distinguished from cholangiocarcinomas by histologic appearance or immunohistochemical pattern, with the exception of colorectal carcinomas. If the patient has a known primary carcinoma, it is most helpful to compare the two tumors.
cyt = cytoplasmic immunoreactivity; nuc = nuclear immunoreactivity.
Bile canalicular pattern. Other carcinomas have a membrane or cytoplasmic pattern.
TTF-1 is seen in the cytoplasm (unlike the nuclear pattern seen in lung and thyroid carcinomas).
Carcinoids arising at sites other than lung are very unlikely to be positive for TTF-1. Lung carcinoids may be positive and are more likely to express CK7.