A case of intrahepatic clear cell cholangiocarcinoma

Rare histotypes of epithelial biliary tract tumors: A literature review

Adenocarcinoma represents the most frequent biliary tract cancer. However, other rare histotypes can be found in the biliary tract, such as cholangiolocellular carcinoma, cholangiocarcinoma with ductal plate malformation pattern, adenosquamous carcinoma, mucinous carcinoma, signet ring cell carcinoma, clear cell carcinoma, mucoepidermoid carcinoma, lymphoepithelioma-like carcinoma, and sarcomatous cholangiocarcinoma. These cancer types account for less than 10 % of all the already rare biliary tract tumors. Yet, they represent a relevant issue in everyday clinical practice, given the lack of therapeutic recommendations and the overall scarcity of data, mainly deriving from isolated small center-specific cohorts of patients.The shifts of such histotypes from the most common ones reflect genetic and molecular differences, determine changes in clinical aggressiveness, and suggest a possible variability in sensitivity to the standard treatments of biliary adenocarcinomas. The consistency and degree of these variables are still to be solidly demonstrated and investigated. Therefore, this paper aims to review the current literature concerning very infrequent and rare epithelial biliary tract cancers, focusing our attention on the clinical, molecular, and immunohistochemical features of these tumors.

Rare Histological Variants of Liver Cancer and Their Management: A Single-Institution Experience

Primary liver malignancies, including hepatocellular carcinoma (HCC) and cholangiocarcinoma, are a major cause of cancer-related morbidity and mortality worldwide. There are several histologically and biologically distinct subtypes of liver cancer that have previously been reported. However, literature regarding the nonsurgical management of these patients upon disease recurrence remains limited. These variants include combined HCC-cholangiocarcinoma (cHCC-CC), Epstein–Barr virus- (EBV-) associated carcinoma, undifferentiated carcinoma, and clear cell or thyroid-like variants of HCC. Here, we aim to highlight the pathologic features, clinical course, and outcomes of five patients with these unusual hepatic tumors and explain the rationale behind the choice of their systemic therapies upon disease recurrence. All patients underwent surgical resection as the standard of care for localized disease, and upon relapse, they were treated with either chemotherapy, targeted therapy, immunotherapy, or active surveillance based on the clinical context and tumor histology. These rare variants are important to recognize as they have prognostic and therapeutic implications, and there are currently insufficient data in the literature to guide further therapy.

Intrahepatic cholangiocarcinoma with clear cell type following laparoscopic curative surgery

Background

Intrahepatic cholangiocarcinoma (ICC) is the second most common malignancy of primary liver cancer. Among the several pathological types of ICC, only five cases of the clear cell type have been reported, including the one presented below. Here we report a unique case of clear cell type ICC following laparoscopic hepatectomy.

Case presentation

A 67-year-old woman had a history of hepatitis B virus. Computed tomography revealed a ring-like enhanced mass 35 mm in diameter at segment 7 in the early phase. The enhancement was prolonged to the late phase through the portal phase, while the shape was irregular. Ethoxybenzy magnetic resonance imaging revealed that the tumor had a low signal intensity on T1-weighted imaging and a high signal intensity on T2-weighted imaging. Diffusion-weighted images identified that the tumor had remarkably high signal intensity. Tumor enhancement was not detected throughout the tumor in the hepatocyte phase. Upon ICC diagnosis, a laparoscopic S7 subsegmentectomy was performed. The patient’s postoperative course was uneventful. An immunohistochemical examination revealed that the cells tested positive for cytokeratin 7 (CK7), CK19, and CD56 and negative for CK20, CD10, α-fetoprotein, thyroid transcription factor-1. At 2 years after surgery, the patient remains alive without recurrence.

Conclusions

Here we presented a case of clear cell ICC that was treated by laparoscopic hepatectomy. Immunological analysis, especially by CD56 and several CK markers, is helpful for diagnosing this disease.

Intrahepatic clear cell cholangiocarcinoma - An uncommon histologic subtype: case report and literature review

Clear-cell cholangiocarcinoma is a very uncommon variant of cholangiocarcinoma with a largely unknown natural history and prognosis. We report a case of a 51-year-old previously healthy woman presenting with a large liver nodule found on routine imaging. Needle biopsy of the lesion suggested a non-hepatocellular carcinoma. After extensive workup for other primary neoplasms, the patient underwent a partial hepatectomy. Histopathology was compatible with a moderately differentiated clear-cell cholangiocarcinoma. There was no evidence of liver disease in the remaining tissue. The patient underwent chemotherapy and remains in clinical remission after two years.

Clear cell hepatocellular carcinoma: origin, metabolic traits and fate of glycogenotic clear and ground glass cells

Clear cell hepatocellular carcinoma (CCHCC) has hitherto been considered an uncommon, highly differentiated variant of hepatocellular carcinoma (HCC) with a relatively favorable prognosis. CCHCC is composed of mixtures of clear and/or acidophilic ground glass hepatocytes with excessive glycogen and/or fat and shares histology, clinical features and etiology with common HCCs. Studies in animal models of chemical, hormonal and viral hepatocarcinogenesis and observations in patients with chronic liver diseases prone to develop HCC have shown that the majority of HCCs are preceded by, or associated with, focal or diffuse excessive storage of glycogen (glycogenosis) which later may be replaced by fat (lipidosis/steatosis). In ground glass cells, the glycogenosis is accompanied by proliferation of the smooth endoplasmic reticulum, which is closely related to glycogen particles and frequently harbors the hepatitis B surface antigen (HBsAg). From the findings in animal models a sequence of changes has been established, commencing with preneoplastic glycogenotic liver lesions, often containing ground glass cells, and progressing to glycogen-poor neoplasms via various intermediate stages, including glycogenotic/lipidotic clear cell foci, clear cell hepatocellular adenomas (CCHCA) rich in glycogen and/or fat, and CCHCC. A similar process seems to take place in humans, with clear cells frequently persisting in CCHCC and steatohepatitic HCC, which presumably represent intermediate stages in the development rather than particular variants of HCC. During the progression of the preneoplastic lesions, the clear and ground glass cells transform into cells characteristic of common HCC. The sequential cellular changes are associated with metabolic aberrations, which start with an activation of the insulin signaling cascade resulting in pre-neoplastic hepatic glycogenosis. The molecular and metabolic changes underlying the glycogenosis/lipidosis are apparently responsible for the dramatic metabolic shift from gluconeogenesis to the pentose phosphate pathway and Warburg-type glycolysis, which provide precursors and energy for an ever increasing cell proliferation during progression.

Cytopathologic, histopathologic, and immunohistochemical features of intrahepatic clear cell bile duct adenoma: a case report and review of the literature

Intrahepatic clear cell bile duct adenoma is extremely rare, with only 3 previous cases reported in the literature. The cause of cytoplasmic clearing in clear cell bile duct adenoma has not been previously investigated. Distinguishing clear cell bile duct adenoma from other clear cell tumors, particularly clear cell cholangiocarcinoma, can be challenging. Previous studies have shown loss of CD10 expression and focal CD56 expression in cholangiocarcinoma. Expressions of CD10 and CD56 have not been previously studied in clear cell bile duct adenoma. A 37-year-old morbidly obese woman was diagnosed with a 2.8 cm intrahepatic clear cell bile duct adenoma following segmental hepatic resection. Histochemical analysis of the tumor suggested the cause of cytoplasmic clearing in the neoplastic cells to be mucin and not glycogen or lipid. On immunohistochemical staining, the neoplastic cells demonstrated staining for CK7, CA 19-9, polyclonal CEA, CD10 (apical), CD56 (focal), and vimentin. Ki-67 highlighted less than 2% of tumor cell nuclei. This is the first report to study the etiology of cell clearing in clear cell bile duct adenoma. Expression of CD10 in clear cell bile duct adenoma may help distinguish clear cell bile duct adenoma from clear cell cholangiocarcinoma.

A case of primary clear cell hepatocellular carcinoma in a non-cirrhotic liver: an immunohistochemical and ultrastructural study

The clear cell variant of hepatocellular carcinoma is a rare entity, occurring at a frequency of less than 10% of hepatocellular carcinoma, with a female prevalence and usually associated with hepatitis C and cirrhosis. We reported a case of primary clear cell hepatocellular carcinoma occurring in a non-cirrhotic liver without history of hepatitis. Our examination included gross pathology, histopathology, immunohistochemistry, special stains, and electron microscopy evaluation. The tumor was composed of sheets of medium-to-large cells with foamy and reticulated cytoplasm and small-to-medium sized nuclei with variably prominent nucleoli. Oil red O stain showed abundant intracellular lipid. Periodic Acid-Schiff stain confirmed the presence of abundant glycogen deposition. Immunohistochemically the tumor cells were positive for Hep Par1, negative for epithelial membrane antigen, steroidogenic factor-1, HMB45, melan A, CK7 and CK20. Electron microscopy study was performed, which was first done in a clear cell hepatocellular carcinoma occurring in a non-cirrhotic liver without elevation of liver function tests. Ultrastructural evaluation of the clear cells showed scarce cellular organelles, cytoplasmic lipid vacuoles and swollen mitochondria.

The use of immunohistochemistry in the diagnosis of metastatic clear cell renal cell carcinoma: a review of PAX-8, PAX-2, hKIM-1, RCCma, and CD10

The diagnosis of metastatic clear cell renal cell carcinoma may be difficult in some cases, particularly in the small image-guided biopsies that are becoming more common. As targeted therapies for renal cell carcinoma are now standard treatment, the recognition and diagnosis of renal cell carcinoma has become even more critical. Many adjunctive immunohistochemical markers of renal epithelial lineage such as CD10 and RCCma have been proposed as aids in the diagnosis of metastatic renal cell carcinoma, but low specificities often limit their utility. More recently described markers (PAX-2, PAX-8, human kidney injury molecule-1, hepatocyte nuclear factor-1-β, and carbonic anhydrase-IX) offer the potential for greater sensitivity and specificity in this diagnostic setting; however, knowledge of their expected staining in other neoplasms and tissues is critical for appropriate use. In this review, we discuss the most widely used immunohistochemical markers of renal lineage with an emphasis on their sensitivity and specificity for metastatic clear cell renal cell carcinoma. Subsequently, we present a variety of organ-specific differential diagnostic scenarios in which metastatic clear cell renal cell carcinoma might be considered and we propose immunopanels for use in each situation.