Li-Fraumeni Syndrome with Unusual Synchronous Malignancies: A Case Report

Li-Fraumeni syndrome (LFS) is a rare autosomal dominant disorder brought on by pathogenic mutations in the TP53 tumor suppressor gene. LFS is characterized by a high lifetime risk of developing various cancers at a relatively young age.

We are presenting a 48-year-old male with a diagnosis of LFS that was confirmed by a genetic test triggered by the patient's son's diagnosis of LFS and leukemia. The patient's main symptoms were abdominal pain and weight loss. The patient was diagnosed with two synchronous primary tumors: first, a metastatic gastric invasive adenocarcinoma that is microsatellite instability (MSI) -high; and second, a low grade (G1) (non-function) well-differentiated pancreatic neuroendocrine tumor. These cancers are not the usual type associated with LFS. After eight cycles of chemo-immunotherapy in the form of FOLFOX-Nivolumab, our radiological assessment showed significant response in the metastatic gastric adenocarcinoma and stable disease in pancreatic neuroendocrine tumor. The patient remains on single agent Nivolumab and has had stable disease for the last 12 months.

Gastric cancer and neuroendocrine tumors are not usually associated with LFS. This case illustrates a rare clinical presentation of multiple malignancies in LFS patients.