First reported case of a collision tumor composed of pancreatic adenocarcinoma and retroperitoneal liposarcoma: a case report

Collision tumors are rare cases with two different tumor entities growing synchronously. While adenocarcinoma of the pancreas is the most common pancreatic tumor with an incidence of 10 per 100.000, retroperitoneal liposarcoma remains very rare. This is the first report of a collision tumor between these two tumor entities. Demographic details: The tumor was diagnosed in a 64 male Caucasian patient. Besides atrial fibrillation, arterial hypertension and a hypothyroidism there is no relevant medical history especially no history of cancer. Clinical details: During a routine check-up an unclassified tumor of the pancreatic tail was diagnosed. The lab showed no pathologies. Tumor markers were negative for carbohydrate antigen 19-9 and 72-4 (CA 19-9, CA 72-4) and carcinoembryonic antigen (CEA). Alpha-fetoprotein (AFP) and neuron specific enolase (NSE) were both elevated (AFP 97kU/l, (