Malignant Transformation of Heterotopic Pancreatic Tissue in a Patient with BRCA2 Mutation

Background: Malignant transformation of heterotopic pancreatic tissue is a rare entity with only several case reports published in the scientific literature. Adjuvant chemotherapy following oncological resection for lesions with nodal metastasis has not been well described and there are no guidelines available to guide the management of these patients. Case Presentation: We present a case of gastric heterotopic pancreatic carcinoma with nodal metastasis in a young patient with breast cancer gene (BRCA) 2 mutation. He had undergone a laparoscopic wedge resection for a gastric lesion initially thought to be a gastrointestinal stroma tumor. Given the involvement of the wedge resection margins, the patient underwent a distal gastrectomy with oncological lymph nodal clearance. One out of the 33 harvested lymph nodes harboured micrometastasis while the main gastrectomy specimen did not have any residual malignancy. Following the histological diagnosis, he received an adjuvant chemotherapy regime akin to that prescribed for locally advanced pancreatic adenocarcinoma with good response. This is, to our knowledge, also the first such case report in a patient with BRCA2 mutation. Conclusions: Pre-operative diagnostic confirmation is challenging and endoscopic procedures pose significant false negatives. Reports of nodal metastasis following oncological resection are limited and there are no guidelines regarding adjuvant therapies. We would recommend a chemotherapy regimen similar to that for primary locally advanced pancreatic carcinoma in patients found to have nodal metastasis.