Fibrolamellar carcinoma of the liver with a mixture of ordinary hepatocellular carcinoma: a case report

Fibrolamellar Carcinoma: What Is New and Why It Matters

Fibrolamellar carcinoma is distinctive at clinical and histologic levels. A novel DNAJB1-PRKACA fusion gene characterizes almost all cases, distinguishes it from other hepatocellular neoplasms, and drives the pathogenesis of this unique tumor. A subset of cases of fibrolamellar carcinoma is associated with alternate mechanisms of protein kinase A activation. This review article discusses common and unusual histologic features of fibrolamellar carcinoma, its differential diagnoses, and how to make the diagnosis while avoiding key pitfalls. The impact of the discovery of the fusion gene on the understanding of the tumor and the prognosis of fibrolamellar carcinoma are also discussed.

Hepatocellular carcinoma with both fibrolamellar and classical components: an unusual morphological pattern

Fibrolamellar carcinoma (FLC) is an uncommon form of primary liver malignancy with unique clinical, histological, and biological characteristics. It is usually seen in young adults without underlying liver disease. Histologically, it shows large cells with abundant eosinophilic cytoplasm, large vesicular nuclei, prominent nucleoli, and lamellar type fibrosis. In contrast, classical hepatocellular carcinoma (HCC) is typically present in elderly male patients with cirrhosis. It is the most common histological subtype, and it is characterized by its resemblance to the normal liver, both in its growth pattern and its cytology. The unusual case of a liver carcinoma that presented with histological features of both FLC and classical HCC is herein reported. This was the case of a 37-year-old female complaining of diffuse abdominal discomfort and epigastric pain for two months. She was referred to us for further management after she was diagnosed with HCC in a noncirrhotic liver. She underwent a left-sided hepatectomy. A yellow nodular mass with well-defined borders and a necrotic center was present in the resection specimen. The morphological features and immunohistochemical studies were consistent with a diagnosis of FLC mixed with classical HCC. The patient was followed up for five months, and no signs of recurrence were evident.

Combined hepatocellular carcinoma and fibrolamellar carcinoma presenting as two adjacent separate lesions in a young boy: first case report from Asia

We report a rare case of combined hepatocellular carcinoma and fibrolamellar carcinoma arising in a noncirrhotic liver, in a 14-year-old boy who underwent right hepatectomy. We discuss the clinicopathological and immunohistochemical features and the clinical outcome in this unusual tumor.

Fibrolamellar carcinoma: 2012 update

Fibrolamellar carcinomas are a unique type of primary liver cancer. They occur most commonly in children and young adults. Their etiology remains a mystery, as they are not associated with chronic liver disease. Fibrolamellar carcinomas are not indolent tumors, but have an overall better prognosis than typical hepatocellular carcinomas, in part because of the younger age at presentation and the lack of cirrhosis. The most important prognostic feature is whether the tumor is resectable. Histologically, the tumor is made up of large cells that contain abundant mitochondria. The nuclei of the tumor cells have prominent nucleoli. The tumor cells induce the formation of extensive intratumoral fibrosis, which often grows in parallel, or lamellar bands. The tumor cells clearly show hepatocellular features but are also unique in showing both biliary and neuroendocrine differentiation. The uniqueness of fibrolamellar carcinoma extends to their molecular findings. While the genetic abnormalities that lead to fibrolamellar carcinomas are not yet known, studies have shown that they lack mutations in the genes most commonly mutated in typical hepatocellular carcinoma (TP53 and CTNNB1). In this paper, the clinical, pathological, and basic science literature on fibrolamellar carcinoma is comprehensively reviewed. Key areas of needed research are also discussed.

Pure and mixed fibrolamellar hepatocellular carcinomas differ in natural history and prognosis after complete surgical resection

BACKGROUND

The purpose of the current study was to describe pure and mixed fibrolamellar hepatocellular carcinoma (FL-HCC).

METHODS

Consecutive patients with pure and mixed FL-HCC were identified from a central pathological review using Edmondson's criteria. Clinical, pathological, and epigenetic characteristics of patients who underwent curative surgery were evaluated. Overall and disease-free survival as well as patterns of disease recurrence were examined. Methylation levels of L1 retrotransposon (LINE-1) repetitive elements and Ras association domain family 1A gene (RASSF1) promoter were also assessed using pyrosequencing.

RESULTS

Forty of 53 patients with a median age of 22 years (range, 9 years-;65 years) met the criteria for analysis. Central pathological review found that 30 patients (75%) had pure and 10 patients (25%) had mixed FL-HCC. Pure FL-HCC typically occurred in patients aged < 30 years. These patients often presented with lymph node metastasis at the time of diagnosis and frequently experienced extrahepatic recurrences (n = 16). Conversely, mixed FL-HCC appeared to resemble to classic HCC, occurring in patients aged > 40 years and frequently involving the liver as the primary site of disease recurrence. With a median follow-up of 7.8 years, the median overall survival from the time of diagnosis in all patients was 6.4 years (range, 3.2 years-12 years). Multivariate analysis found that the risk of death was increased in patients with higher American Joint Committee on Cancer disease stages (P = .003) and those with mixed FL-HCC (P = .03). Methylation analysis of LINE-1 repetitive elements and RASSF1 promoter revealed different methylation levels between pure and mixed FL-HCC, suggesting a different epigenetic background.

CONCLUSIONS

Pure and mixed FL-HCC display distinct clinical presentations and epigenetic backgrounds leading to different prognoses and as such may be regarded as separate clinical entities.

Fibrolamellar hepatocellular carcinoma

Fibrolamellar hepatocellular carcinoma (FHLCC) generally occurs in young individuals lacking a background of chronic liver disease and other risk factors for hepatocellular carcinoma. The clinical presentations of FLHCC are generally nonspecific, and the alpha-fetoprotein level is typically within the normal range in most cases. Imaging studies have a major role in clinical diagnosis, but pathology is the gold standard in confirming diagnosis. Pathological characteristics of FLHCC include the presence of tumor cells with a deeply eosinophilic cytoplasm and macronucleoli surrounded by abundant fibrous bands. The most effective treatment for FLHCC is aggressive surgical resection. This comprehensive literature review gives a full account of the clinical, pathological, and molecular features of FLHCC.

Review of the clinicopathologic features of fibrolamellar carcinoma

Since its first description 50 years ago, fibrolamellar carcinomas (FLCs) have been recognized as a unique type of primary liver cancer. FLCs occur principally in children and young adults and are not associated with chronic liver disease. Their etiology is unknown. The tumor is made up of large polygonal cells containing abundant eosinophilic cytoplasm, large vesiculated nuclei, and large nucleoli, with tumor cells that are embedded in lamellar bands of fibrosis. Although rare, the most common variant of FLC shows areas of glandular type differentiation with mucin production. The uniqueness of FLC extends to their molecular findings, as they show no evidence for involvement by many of the major pathways and genes that are dysregulated in typical hepatocellular carcinoma, including alpha-fetoprotein, TP53 mutations, and beta catenin mutations. FLCs are not indolent tumors, but have an overall better prognosis than hepatocellular carcinomas of the usual sort because of the younger age at presentation and lack of cirrhosis. The most important prognostic feature is resectability. Although their morphologic appearance on routine stains is well defined, their etiology is still unknown and much of their molecular biology remains poorly described and awaits future investigation.

Adult-type hepatocellular carcinoma in the center of a fibrolamellar hepatocellular carcinoma

A large hepatic tumor was detected in the noncirrhotic liver of a 27-year-old female patient. The tumor was radiologically characterized by a peripheral mass encircling a central ovoid tumor, and was resected by an extended right hemihepatectomy. Histologic examination revealed that the peripheral and major component of the tumor represented a fibrolamellar hepatocellular carcinoma, whereas the central, well-demarcated tumor was a less well-differentiated adult-type hepatocellular carcinoma completely encircled by the former. Cells of the peripheral tumor mass abundantly expressed cytokeratin-7, typically present in the fibrolamellar variant, whereas no cytokeratin-7 immunoreactivity was found in the central tumor. To our knowledge, this is the first reported case of a not admixed but clearly separated evolution of these 2 histologic patterns within the same tumor, and suggests that the 2 types of hepatocellular carcinoma may share a common pathogenic pathway.