Fibrolamellar hepatocellular carcinoma: an immunohistochemical comparison with conventional hepatocellular carcinoma.

The fibrolamellar variant of hepatocellular carcinoma (FLC) differs from conventional hepatocellular carcinoma (HCC) in some clinical and pathological features. The authors investigated possible differences in reactivity between FLCs and HCCs using glypican-3 (GPC3), an oncofetal protein, and survivin, an antiapoptotic protein. They also compared staining of FLC and HCC with antibodies to cytokeratins 7 (CK7) and 19 (CK19) and CD34. GPC3 was significantly more often and more strongly expressed in HCCs (72%) than in FLCs (17%). Survivin nuclear translocation in tumor cells did not differ between HCCs (10%) and FLCs (9%). There was more abundant expression of CK7 in FLCs (92%) than in HCCs (33%), whereas CK19 was more often found in HCCs (20%) than in FLCs (5%). All tumors had CD34-positive sinusoids. This study shows that FLCs and HCCs differ in the expression of GPC3, CK7, and CK19 and that there is a lack of difference as regards survivin and CD34.

Calcifying nested stromal-epithelial tumors of the liver: a clinicopathologic, immunohistochemical, and molecular genetic study of 9 cases with a long-term follow-up.

There is a rare primary liver tumor that has been reported as "ossifying stromal-epithelial tumor" (3 cases), "desmoplastic nested spindle cell tumor" (4 cases), and "nested stromal-epithelial tumor" (6 cases). Herein we report 9 cases of this tumor, including 3 previously reported, from the files of the Armed Forces Institute of Pathology. All tumors were discovered incidentally in patients between 2 and 33 years of age. Four had a history of calcified hepatic nodules since childhood (ages 4 to 10 y). One had Cushing syndrome that abated after excision. Eight patients had a partial hepatectomy and 1 underwent liver transplantation. The tumors ranged from 5.5 to 20 cm and had a characteristic histologic appearance with irregular, sharply circumscribed nests and islands of bland-appearing spindled to focally epithelioid cells, surrounded by a cellular desmoplastic stroma. The tumor nests had focal psammoma-like calcifications with or without ossification. Immunohistochemistry demonstrated at least focal positivity for keratin cocktail AE1/AE3/LP34 in all 9 cases, and Wilms tumor suppressor gene (7/7) with variable staining for other epithelial (except keratins 7 and 20), neural, and mesenchymal markers. None of the tumors was positive for Ewing sarcoma-primitive neuroectodermal tumors, desmoplastic small round cell tumor, and SYT-SSX fusion transcript. Follow-up revealed that 1 patient had 2 local recurrences successfully treated by radiofrequency ablation. The patient who underwent liver transplantation died of postoperative complications. Six patients were alive and well up to 22 years after surgery. We propose the name "calcifying nested stromal and epithelial tumor" for this rare but distinctive clinicopathologic entity of uncertain histogenesis. On the basis of currently available information, this tumor is best considered a low-grade malignancy.

Glypican-3 expression in benign liver tissue with active hepatitis C: implications for the diagnosis of hepatocellular carcinoma.

Glypican 3 is an oncofetal antigen that shows great promise as an adjunct to the diagnosis of hepatocellular carcinoma. To investigate whether glypican 3 might also appear in nonneoplastic liver cells, we performed immunostains on 60 biopsies of chronic hepatitis C, 30 with low-grade activity and 30 with high-grade activity. Glypican 3 immunoreactivity was detected in 25 (83.6%) of 30 in the high-grade but in none in the low-grade group. In 20% of the positive cases, glypican 3 produced strong cytoplasmic staining of more than 25% of hepatocytes and could potentially lead to a misdiagnosis of hepatocellular carcinoma. Pathologists should be aware of this phenomenon and exercise caution in interpreting biopsies or other specimens of suspected hepatocellular carcinoma when active necroinflammatory disease is present.

Expression of estrogen and progesterone receptors and inhibin-alpha in hepatobiliary cystadenoma: an immunohistochemical study.

To further characterize the immunohistochemical features of hepatobiliary cystadenoma with mesenchymal stroma, a battery of stains was performed on nine typical cases. All nine tumors had been resected from female patients who ranged in age from 30 to 59 years. Freshly cut sections were stained with antibodies to estrogen receptor (ER), progesterone receptor (PR), alpha-smooth muscle actin (SMA), inhibin-alpha, and cytokeratins (CK) 7, 8, 18, and 19. Nuclear staining of the mesenchymal stromal cells for ER and PR was present in all and seven out of nine cases, respectively. A strong cytoplasmic staining of the mesenchymal stromal cells for SMA was seen in all cases. A patchy pale cytoplasmic staining of the tumor epithelium for ER and PR was seen in five out of nine and four out of nine cases, respectively. Immunoreactivity of luteinized stromal cell for inhibin-alpha was documented in three out of nine cases. All tumors (nine out of nine) demonstrated strong cytoplasmic positivity of the epithelial lining of the cysts to CK7, CK8, CK18, and CK19, typical of biliary-type epithelium. The expression of ER, PR, and inhibin-alpha in the ovarian-like stroma supports the likely hormonal dependence of this tumor and probably explains its almost exclusive occurrence in women.

Diagnosis of focal nodular hyperplasia of the liver by needle biopsy.

Focal nodular hyperplasia (FNH) of the liver can be a difficult diagnosis to establish in limited diagnostic samples such as a needle-core tissue biopsy, especially for pathologists with limited experience with the lesion. To characterize the features that can be used to make the diagnosis, we reviewed and analyzed the clinicopathologic features of 100 consecutive cases submitted for consultation in which we were confident of the diagnosis of FNH in needle biopsy material. A diagnosis of FNH was correctly made by the contributing pathologist in 24 of the 100 referred cases. Most of the patients (81%) were women of childbearing age with a mean age of 36.75 +/- 9.82 years. Most of the patients (70%) were asymptomatic at diagnosis. The most consistent diagnostic histological feature of FNH in needle biopsy was the presence of ductular reaction with varied intensity at the junction of the fibrous septa with the hepatocellular component, which was present in all 100 cases. Thick abnormal arteries were seen in all but 2 cases (n = 98). Features of chronic cholestasis with cholate stasis and accumulation of copper (demonstrable by the rhodanine stain) and copper-binding protein (demonstrable with the Victoria blue stain) were nearly as common (n = 94). A confident diagnosis of FNH can be made with a needle biopsy, especially if the biopsy is known to come from a mass, and the lesion contains characteristic fibrosis with ductules at the interface between hepatocytes and the fibrous region, prominent arteries, and benign hepatocytes with features of chronic cholestasis.