The current study examined sarcomatoid intrahepatic cholangiocarcinoma (S-iCCA). S-iCCA was a more aggressive subtype of intrahepatic cholangiocarcinoma (iCCA). Early detection and complete resection of tumors are very important. Reported here is a case of S-iCCA, and the diagnosis and treatment of S-iCCA are discussed. The patient underwent a tumor resection and was treated with chemotherapy and molecularly targeted drugs after surgery. The clinical pathologic features and treatment of S-iCCA are discussed based on the literature. An immunohistochemical examination revealed positivity for cytokeratin 7 (CK7), CK-pan, vimentin, and CK19 and negativity for hepatocyte paraffin 1 (HepPar-1) in sarcomatoid cells. This case suggests that the particular molecular characteristics of sarcomatoid cells have great clinical diagnostic value, and comprehensive treatment of S-iCCA based on surgery is described.

Sarcomatoid intrahepatic cholangiocarcinoma (S-iCCA) is a rare variant of primary liver cancer with a poor prognosis due to local aggressive expansion and frequent metastases. The pathogenesis remains unclear, but theories suggest epithelial-mesenchymal transition, biphasic differentiation of pluripotent stem cells, or sarcomatoid re-differentiation of immature multipotent carcinoma cells. Chronic hepatitis B and C, cirrhosis, and age above 40 are plausible contributors. Diagnosis of S-iCCA requires immunohistochemical evidence of both mesenchymal and epithelial molecular expression. Early detection and total resection are the current mainstay approach. We report a case of metastatic S-iCCA in a 53-year-old male with alcohol use disorder who underwent en bloc right hepatic lobectomy, right adrenalectomy, and cholecystectomy.

Sarcomatoid carcinoma is a rare tumor that is composed of a mixture of malignant epithelial cells and mesenchymal cells. Many studies have reported that sarcomatoid carcinoma occurs in multiple organs including the liver. Sarcomatoid intrahepatic cholangiocarcinoma (S-iCCA) is an extremely rare tumor that primarily occurs in the liver. This case occurred in a middle-aged man who was admitted to our hospital with abdominal pain. Enhanced computed tomography of the abdomen showed a low-density mass in the upper right posterior lobe of the liver with enhancement in the periphery. Histological and immunohistochemical examination indicated that the tumor was malignant, with both cancer and sarcoma components, and was positive for cytokeratin and vimentin. The patient was diagnosed with S-iCCA. Metastases appeared in the liver and lung 4 months after surgery. Two cycles of chemotherapy were administered. Because of enlargement of the tumor, anti-angiogenic agents combined with immunotherapy were subsequently given to achieve disease control. To the best of our knowledge, this is the first reported case of a programmed cell death-1 inhibitor used in a S-iCCA patient. The purpose of this case report and literature review is to enhance clinician understanding of S-iCCA and to explore safe and effective treatment methods.

Sarcomatoid intrahepatic cholangiocarcinoma (S-iCCA) is a rare histological variant of intrahepatic cholangiocarcinoma (iCCA). The diagnosis of S-iCCA is based on histopathological and immunohistochemical examinations, and S-iCCA often has a poorer prognosis than that of ordinary iCCA. In this article, we present the case of a 64-year-old man with S-iCCA who presented with intermittent right upper abdominal pain. The aim of this case report and literature review is to strengthen the understanding of S-iCCA among clinicians and reduce the incidence of missed clinical diagnoses.

BACKGROUND: Sarcomatoid intrahepatic cholangiocarcinoma (SICC) is an extremely rare and highly invasive malignant tumor of the liver. To our knowledge, the imaging findings of sarcomatous cholangiocarcinoma have been rarely reported; and radiological features of this tumor mimicking liver abscess have not yet been reported.
METHODS: We present a case of SICC mimicking liver abscess. The patient, a 43-year-old male, complained of repeated upper right abdominal discomfort and intermittent distension over a period of one month. Radiology examination revealed a huge focal lesion in the right liver. The lesion was hypointense on computed tomography with honeycomb enhancement surrounded by enhanced peripheral areas. It showed a hypo-signal on non-contrast T1-weighted images and a hyper-signal on non-contrast T2-weighted images. Radiologists diagnosed the lesion as an atypical liver abscess. The patient underwent a hepatectomy. After surgery, he survived another 2.5 mo before passing away. A search of PubMed and Google revealed 43 non-repeated cases of SICC reported in 20 published studies. The following is a short review in order to improve the diagnostic and therapeutic skills in cases of SICC.
CONCLUSIONS: This report presents the clinical and radiological features of SICC and imaging features which showed hypovascularity and progressive enhancement. SICC can present as a multilocular cyst on radiological images and it is necessary to distinguish this lesion from an atypical abscess. Simple surgical treatment is not the best treatment option for this disease.