IMMUNOHISTOCHEMISTRY IN THE DIFFERENTIAL DIAGNOSIS OF THE LIVER MASSES

Liver is an organ which can harbour a wide variety of masses neoplastic and nonneoplastic; benign and malignant; primary and metastatic. Tru-cut biopsy is a frequently performed sampling method for diagnosis of liver masses. We evaluated our diagnostic approach to this kind of biopsies by reviewing our three month-tru-cut biopsy experience.
We reviewed 40 patients biopsied for the diagnosis of liver masses. We performed immunohistochemistry on 27 (67.5%) of them and used cytokeratins 7, 20, 19, HepPar1, alpha-fetoprotein and several specific tumor markers for differential diagnosis.
Forty patients with an age range between 1-83 years and a mean of 40 years, were 24 (60%) males and 16 (40%) females. Twelve (30%) patients had primary, 21 (52.5%) had secondary tumors and one (2.5%) patient had a mass lesion diagnosed as nonnoplastic. Six (15%) biopsies were reported to be unsatisfactory for diagnosis. There were 6 hepatocellular carcinomas, 3 cholangiocarcinomas, one angiosarcoma, one infantile hemangioendothelioma and one hemangioma among the primary tumors. Thirteen of the secondary masses originated from gastrointestinal system and five of them had the features of endocrine carcinoma histomorphologically and immunohistochemically. We were unable to find out the origin of four metastatic masses.
With an immunohistochemistry panel arranged in the guidance of clinical and radiological information and histomorphological features, it is possible to detect the cellular origin of the tumor in 75% of the patients. In order to take as much benefit as possible from this diagnostic method, the importance of clinical and radiological information should always be kept in mind. Arranging the immunohistochemistry panel in the guidance of sufficient clinical and radiological information, and the usage of cytokeratins 7 and 20 as the first step in the immunohistochemical evaluation are the most important factors to achieve the correct diagnosis.

Keywords: Liver, needle biopsy, metastasis, hepatocellular carcinoma, immunohistochemistry