Gastric Carcinosarcoma and 18F-FDG PET/CT

First report on establishment and characterization of the extrahepatic cholangiocarcinoma sarcoma cell line CBC2T-2

BACKGROUND

Extrahepatic cholangiocarcinoma sarcoma is extremely rare in clinical practice. These cells consist of both epithelial and mesenchymal cells. Patient-derived cell lines that maintain tumor characteristics are valuable tools for studying the molecular mechanisms associated with carcinosarcoma. However, cholangiocarcinoma sarcoma cell lines are not available in cell banks.

AIM

To establish and characterize a new extrahepatic cholangiocarcinoma sarcoma cell line, namely CBC2T-2.

METHODS

We conducted a short tandem repeat (STR) test to confirm the identity of the CBC2T-2 cell line. Furthermore, we assessed the migratory and invasive properties of the cells and performed clonogenicity assay to evaluate the ability of individual cells to form colonies. The tumorigenic potential of CBC2T-2 cells was tested in vivo using non-obese diabetic/severe combined immunodeficient (NOD/SCID) mice. The cells were injected subcutaneously and tumor formation was observed. In addition, immunohistochemical analysis was carried out to examine the expression of epithelial marker CK19 and mesenchymal marker vimentin in both CBC2T-2 cells and xenografts. The CBC2T-2 cell line was used to screen the potential therapeutic effects of various clinical agents in patients with cholangiocarcinoma sarcoma. Lastly, whole-exome sequencing was performed to identify genetic alterations and screen for somatic mutations in the CBC2T-2 cell line.

RESULTS

The STR test showed that there was no cross-contamination and the results were identical to those of the original tissue. The cells showed round or oval-shaped epithelioid cells and mesenchymal cells with spindle-shaped or elongated morphology. The cells exhibited a high proliferation ratio with a doubling time of 47.11 h. This cell line has migratory, invasive, and clonogenic abilities. The chromosomes in the CBC2T-2 cells were polyploidy, with numbers ranging from 69 to 79. The subcutaneous tumorigenic assay confirmed the in vivo tumorigenic ability of CBC2T-2 cells in NOD/SCID mice. CBC2T-2 cells and xenografts were positive for both the epithelial marker, CK19, and the mesenchymal marker, vimentin. These results suggest that CBC2T-2 cells may have both epithelial and mesenchymal characteristics. The cells were also used to screen clinical agents in patients with cholangiocarcinoma sarcoma, and a combination of paclitaxel and gemcitabine was found to be the most effective treatment option.

CONCLUSION

We established the first human cholangiocarcinoma sarcoma cell line, CBC2T-2, with stable biogenetic traits. This cell line, as a research model, has a high clinical value and would facilitate the understanding of the pathogenesis of cholangiocarcinoma sarcoma.

An Unusual Case of Esophageal Carcinosarcoma on 18F-FDG PET/CT

ABSTRACT

Carcinosarcoma of the esophagus is a rare malignant neoplasm. Here, we report a case of esophageal carcinosarcoma with lymphatic and pulmonary metastases on 18F-FDG PET/CT in a 64-year-old woman.

True hypopharyngeal carcinosarcoma: a case report and literature review

Objective

Carcinosarcoma consists of carcinomatous and sarcomatous tissues and is an aggressive malignant tumor. It is rarely reported in the hypopharynx.

Methods

A 72-year-old man presented with dysphagia and dyspnea. Laryngoscopy, computed tomography (CT), and ¹⁸F-fluorodeoxyglucose positron emission tomography/CT (¹⁸F-FDG PET/CT) showed a neoplasm on the left posterior hypopharyngeal wall. The patient underwent bilateral neck dissection and excision of the hypopharyngeal cancer followed by postoperative radiation therapy.

Results

Immunohistochemistry revealed carcinomatous cells with membrane positivity for cytokeratin, glucose transporter-1 (GLUT-1), phosphoinositide-3 kinase (PI3K), hypoxia-inducible factor-1α (HIF-1α), and hexokinase-II as well as sarcomatous cells with membrane positivity for smooth muscle actin, GLUT-1, HIF-1α, and PI3K. Histopathology and immunohistochemistry revealed a true carcinosarcoma of the hypopharynx (pT3N0M0, Stage III).

Conclusions

Thorough immunohistochemistry is required for a correct diagnosis of hypopharyngeal carcinosarcoma. ¹⁸F-FDG PET/CT may help to distinguish hypopharyngeal carcinosarcoma from benign tumors.

FDG PET/CT in Sarcomatoid Carcinoma of the Gallbladder With Chondroid Differentiation

Sarcomatoid carcinoma of the gallbladder, composed of epithelial and sarcomatous components, is a rare malignant tumor with a poor prognosis. A 61-year-old man was admitted because of abdominal distention for 2 weeks. Enhanced CT showed a large gallbladder tumor with central necrosis. The tumor measuring 18 cm in maximum diameter showed intense peripheral FDG uptake with SUVmax of 15.4. The specimen of the resected tumor revealed tubular adenocarcinoma and sarcomatoid tissue with chondroid differentiation. Immunohistochemical staining showed the sarcomatoid tissue was positive for EMA, CD10, and VIM, with proliferation index of 80%. These pathologic findings were consistent with sarcomatoid carcinoma.

Primary Liver Carcinosarcoma and 18F-FDG PET/CT

Primary liver carcinosarcoma is a very rare, malignant neoplasm that is concomitantly composed of a mixture of sarcomatous and carcinomatous elements. In the present study, an initial staging FDG PET/CT showed intense FDG uptake in a patient with liver carcinosarcoma composed of hepatocellular carcinoma and rhabdomyosarcoma. Two months after surgical resection, a restaging PET/CT showed rapid progression of the disease with abdominal and lung metastases, indicating aggressive feature of the disease. The case shows the importance to repeat a restaging PET/CT at early time after surgery for a patient with liver carcinosarcoma to monitor disease progression.