Pancreatic solitary and synchronous metastasis from breast cancer: a case report and systematic review of controversies in diagnosis and treatment

Background: Metastases from breast cancer cause the frequent involvement of lung, bone, liver, and brain, while the occurrence of metastases to the gastrointestinal tract is rare, and more frequently discovered after a primary diagnosis of breast cancer. Solitary pancreatic metastases from breast cancer, without widespread disease, are actually unusual, and only 19 cases have been previously described; truly exceptional is a solitary pancreatic metastasis becoming evident together with the primary breast cancer. Case presentation: A 68-year-old woman reported general fatigue, lethargy, and jaundice. Abdominal ultrasound (US) and magnetic resonance imaging (MRI) showed an ampulloma of Vater's papilla; moreover, a neoplastic nodule in the left breast was diagnosed. She underwent surgery for both breast cancer and ampulloma of Vater's papilla. Pathological examination of pancreatic specimen, however, did not confirm primary carcinoma of the duodenal papilla, but showed a metastatic involvement of pancreas from lobular breast cancer. Immunohistochemistry has been essential to confirm the origin of the malignancy: hormone receptors and mammaglobin were expressed in both the primary breast tumor and the pancreatic metastasis. Conclusions: This is one of the few reported cases in literature of an isolated and synchronous pancreatic metastasis from breast cancer, where the definitive diagnosis was obtained only after surgery. We discuss the controversies in this diagnosis and the choice of correct treatment. The surgical resection of solitary metastases can be performed in the absence of disseminated disease.