Fine-needle aspiration cytology and differential diagnoses of fibrolamellar hepatocellular carcinoma metastatic to the mediastinum: case report

State-of-the-art MR Imaging of Uncommon Hepatocellular Tumours: Fibrolamellar Hepatocellular Carcinoma and Combined Hepatocellularcholangiocarcinoma

BACKGROUND

Fibrolamellar Carcinoma (FLC) and Combined Hepatocellular- Cholangiocarcinoma (CHC) are rare primary liver tumours, which are related to different clinical settings. In both tumours, correlation with clinical data and laboratory tests are extremely important.

DISCUSSION

Typically, FLC is diagnosed in young patients without any chronic disease and with normal biochemical tests, whereas CHC arises in cirrhotic patients with elevated tumour markers: AFP and/or CA 19-9. The review describes epidemiology, aetiology, pathogenesis, radiological features and treatment of these tumours. Imaging features typical for FLC are: The presence of central scar, calcifications, the large size, heterogeneous and early contrast-enhancement.

CONCLUSION

The diagnosis of CHC may be suggested in case of elevation of both AFP and CA 19- 9 or inconsistency between elevated tumour markers and imaging findings (i.e., elevated CA 19-9 and radiological features of HCC, or elevated AFP with imaging findings characteristic of ICC).

Utility of Cytokeratin7 Immunocytochemistry in the Cytopathological Diagnosis of Fibrolamellar Hepatocellular Carcinoma

Objective

To distinguish fibrolamellar hepatocellular carcinoma (FL-HCC) variant from the conventional hepatocellular carcinoma (HCC) by cytology, immunocytochemistry, and morphometry.

Study Design

Retrospective detailed cytomorphological, immunocytochemical, and morphometric analysis was performed in 6 cases of FL-HCC reported on fine needle aspiration. Cell block immunocytochemistry (CB-ICC) for CK7 and CD68 was performed in four cases. Morphometry was carried out with Cell A software. Area of the cell, nucleus and nucleolus was measured in 50 nuclei per case in 6 cases each of FL-HCC and HCC.

Results

The mean age of patients with FL-HCC was 19 years and all had normal serum alpha-fetoprotein levels. Fine needle aspiration smears showed large polygonal cells with abundant cytoplasm, vesicular nucleus and prominent nucleolus, associated with variably cellular fibrous stromal fragments. Intranuclear inclusions, cytoplasmic eosinophilic inclusions, and bile were also noted. FL-HCC showed strong membrano-cytoplasmic CK7 positivity and cytoplasmic granular and canalicular positivity for CD68. In contrast, HCC showed weak focal positivity for CK7 and only canalicular CD68 positivity. Morphometry revealed that FL-HCC cells were 2.19 times the size of HCC.

Conclusion

CK7 immunocytochemistry on cell blocks is useful for confirming and distinguishing it from HCC.

Hepatocellular Carcinoma, Fibrolamellar Variant: Diagnostic Pathologic Criteria and Molecular Pathology Update. A Primer

Fibrolamellar hepatocellular carcinoma (FL-HCC) is generally a fairly rare event in routine pathology practice. This variant of hepatocellular carcinoma (HCC) is peculiarly intriguing and,in addition, poorly understood. Young people or children are often the target individuals with this type of cancer. Previously, I highlighted some pathology aspects of FL-HCC, but in this review, the distinctive clinico-pathologic features of FL-HCC and the diagnostic pathologic criteria of FL-HCC are fractionally reviewed and expanded upon. Further, molecular genetics update data with reference to this specific tumor are particularly highlighted as a primer for general pathologists and pediatric histopathologists. FL-HCC may present with metastases, and regional lymph nodes may be sites of metastatic spread. However, peritoneal and pulmonary metastatic foci have also been reported. To the best of our knowledge, FL-HCC was initially considered having an indolent course, but survival outcomes have recently been updated reconsidering the prognosis of this tumor. Patients seem to respond well to surgical resection, but recurrences are common. Thus, alternative therapies, such as chemotherapy and radiation, are ongoing. Overall, it seems that this aspect has not been well-studied for this variant of HCC and should be considered as target for future clinical trials. Remarkably, FL-HCC data seem to point to a liver neoplasm of uncertain origin and unveiled outcome. A functional chimeric transcript incorporating DNAJB1 and PRKACA was recently added to FL-HCC. This sensational result may give remarkable insights into the understanding of this rare disease and potentially provide the basis for its specific diagnostic marker. Detection of DNAJB1-PRKACA seems to be, indeed, a very sensitive and specific finding in supporting the diagnosis of FL-HCC. In a quite diffuse opinion, prognosis of this tumor should be reconsidered following the potentially mandatory application of new molecular biological tools.

Adrenocorticotropic hormone-producing thymic neuroendocrine carcinoma with oncocytic features: a case report and review of literature

Thymic neuroendocrine carcinomas are the most common mediastinal neuroendocrine tumor. These malignancies are not often diagnosed by fine-needle aspiration (FNA), as they are more commonly diagnosed by biopsy or excision. We describe a case of a FNA of a paratracheal mass from a 38-year-old man who presented with Cushing syndrome. A low-grade neuroendocrine carcinoma with oncocytic features was diagnosed, which was later confirmed by excision of the thymus, anterior mediastinal and paratracheal soft tissue, and lymph nodes. Oncocytic features in these tumors are a rare finding and bring metastatic medullary thyroid carcinomas as well as other metastases into the differential diagnosis. The prognosis of neuroendocrine carcinomas in this location is worse than neuroendocrine carcinomas in other areas, and close follow-up is recommended.

Fibrolamellar hepatocellular carcinoma with biliary tumor thrombus: an unreported association

Fibrolamellar hepatocellular carcinoma (FHCC) is a rare malignant tumor of hepatocyte origin occurring earlier in life than typical hepatocellular carcinoma (HCC). We describe a distinctive case of FHCC with biliary tumor thrombus (BTT) in a 25-year-old Caucasian patient, pointing out the imaging features supported by histopathology.

Diagnosis of metastatic fibrolamellar hepatocellular carcinoma by endoscopic ultrasound-guided fine needle aspiration

The fibrolamellar variant of hepatocellular carcinoma (FL-HCC) is distinguished from other hepatocellular carcinomas (HCC) by its unique clinical and pathologic features. Cytological features for this tumor on fine needle aspiration (FNA) of primary tumors have been described earlier. We present here a unique case of metastatic FL-HCC diagnosed by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of mediastinal adenopathy. A 32-year-old woman with a history of oral contraceptive use presented with nausea and severe abdominal pain but no ascites or stigmata of cirrhosis. She had a past history of resection of a liver lesion. Serial computed tomography scans revealed mediastinal lymphadenopathy and the patient was referred for endoscopic ultrasound (EUS). A transesophageal EUS-FNA was performed and tissue was collected for cytological evaluation by an on-site pathologist with no knowledge of prior history. Based on morphology correlated with prior history received later, a final diagnosis of metastatic FL-HCC in the retrocardiac lymph node was rendered on the EUS-FNA samples. There are very few reports in the literature where a diagnosis of FL-HCC is rendered at unusual sites. This case highlights that EUS-FNA is a relatively non-invasive, rapid, accurate and effective modality in obtaining tissue from otherwise hard-to-reach areas. It also suggests that metastasis of FL-HCC can be observed in mediastinal nodes and that diagnosis based on cytological features can be rendered even when the tumor is identified at unusual locations.

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.

Fibrolamellar hepatocellular carcinoma: A case report with cytological features in a sixteen-year-old girl

We report a case of a 16-yr-old girl with a liver tumor revealed by thrombophlebitis of the left leg. On physical examination the patient was found to have painless hepatomegaly. Ultrasound and CAT scan showed a large tumor of the left portion of the liver, measuring 14 cm in diameter. Cytological preparations were touch imprints of the biopsy fragments obtained under ultrasound guidance. Cytological examination using May-Grünwald Giemsa stain revealed highly cellular smears containing large tumor cells with a round nucleus, prominent nucleoli, and abundant granular basophilic cytoplasm. Cytological features were those of fibrolamellar hepatocellular carcinoma, confirmed by histological examination of the biopsy sample as well as the surgical specimen obtained after wide excision of the lesion following ineffective neoadjuvant chemotherapy.