Multiple primary gastrointestinal tumors of gastric, pancreatic and rectal origin; a case report.

Introduction: The occurrence of multiple primary synchronous or metachronous malignancies is a described phenomenon. Such cases may have genetic predisposition or could be related to environmental risk factors but may also be sporadic. We are reporting a unique combination of triple primary synchronous malignancies in the same patient.

Case Presentation: A 71 year old man presented with constipation and per rectal bleeding with a palpable mass 5-6 cm from the anal verge on physical examination. Colonoscopy with biopsy confirmed adenocarcinoma of rectal origin. After multi-disciplinary tumor board meeting, the patient received neoadjuvant chemoradiation therapy followed by single-stage surgery. Re-staging work up showed the presence of pancreatic lesion. Incidental finding of a gastric nodule upon surgical exploration which was confirmed to be a gastrointestinal stromal tumor. The patient had an uneventful postoperative course.

Discussion: Multiple primary malignancies of the gastrointestinal system has previously been reported in the literature; whether in the form of double, triple, quadruple or even quintuple primaries. Furthermore, gastrointestinal malignancies have been reported to be combined with extra-intestinal malignancies. However, this unique combination of pancreatic adenocarcinoma, rectal adenocarcinoma and gastric gastrointestinal stromal tumor has not been previously reported in the literature. Single-stage multiple resections was successful.

Conclusion: We are reporting a unique case of three primary malignancies involving the rectum, pancreas and stomach. For such patients, there is no clear guidelines regarding management or surveillance, but rather should be individualized.