Pancreatic adenocarcinosarcoma of monoclonal origin: A case report

Abstract

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.

Systemic Chemotherapy for Advanced Rare Pancreatic Histotype Tumors

“…Gemcitabine alone resulted ineffective in 2 advanced cases. 103,106 Among 4 of our 5 patients, 2 were treated with gemcitabine plus nab-paclitaxel, and 2 were treated with gemcitabine plus FU. All of them showed a PD with an OS equal to or shorter than 5 months.…”

Pancreatic carcinosarcoma with rare long-term survival

“…The disease was usually detected during physical examination [ 4 ] or while treating other diseases such as anemia, [ 2 ] deep vein thrombosis of lower limb, [ 5 ] or glucose abnormality. [ 6 ] The levels of tumor marker CA-199 were obviously increased in most patients. No typical characteristics of carcinosarcoma were seen during imaging.…”

“…Most of the cases reviewed by us were ductal adenocarcinoma, mucinous cystadenocarcinoma, [ 9 ] and intraductal papillary mucinous carcinoma. [ 6 ] Due to the low degree of differentiation, sarcoma in most cases consists of polymorphic spindle cells. However, leiomyosarcoma, [ 10 ] osteosarcoma, [ 4 ] and osteoclast giant cell tumor [ 11 ] were predominantly seen in other cases.…”

“…Malignancy of pancreatic carcinosarcoma is usually high. Previous studies indicated invasion of peripancreatic adipose tissue [ 2 , 3 , 4 , 5 , 9 , 18 ] and duodenal wall [ 5 , 16 , 17 , 18 ] in most cases, or metastasis of surrounding lymph nodes [ 2 , 3 , 5 , 9 , 16 ] and other organs such as liver, [ 6 , 15 ] resulting in poor prognosis. Gelos et al [ 2 ] found that the average postoperative survival time was 6 months.…”