Published online Sep 21, 2014. doi: 10.3748/wjg.v20.i35.12682
Revised: April 30, 2014
Accepted: July 24, 2014
Published online: September 21, 2014
Adenocarcinosarcoma, a neoplasm containing both carcinomatous and sarcomatous components, is a rare form of a cancer and the pathophysiology is currently poorly understood. Moreover, definitive treatment guidelines for this disease have not yet been established. Pancreatic adenocarcinosarcoma is even more rare and the prognosis is fatal. Here, we report a case of a 77-year-old male with pancreatic adenocarcinosarcoma and metastasis to the liver. The patient presented at our hospital with uncontrolled glucose levels and diabetes mellitus. The patient’s laboratory findings were unremarkable with the exception of elevated carbohydrate antigen 19-9 levels. Biopsies of the tumors in the pancreas and the liver revealed two types of tumors: pancreatic adenocarcinoma and a poorly differentiated sarcoma. To determine if KRAS mutations were present, we performed a peptide nucleic acid (PNA) clamp PCR-based assay. DNA sequencing by PNA clamp PCR identified a point mutation in codon 12 of exon 2 within KRAS from both tumor types. Because the KRAS mutation is observed in both tumor components, our findings support a monoclonal tumor origin followed by subsequent divergent differentiation into the sarcomatous and carcinomatous tumor populations. After we considered the patient’s status and the late stage of tumor detection, gemcitabine chemotherapy was administered.
Core tip: Pancreatic adenocarcinosarcoma is a very rare form of cancer. Here, we present a case report of a 77 year-old male with pancreatic adenocarcinosarcoma and metastasis to the liver. Using peptide nucleic acid clamp PCR, we identified a mutation in KRAS in both tumors. These results indicate that both the sarcomatous and carcinomatous components of the tumor likely arose from a monoclonal origin.