KIT Mutation in Gastric Gastrointestinal Stromal Tumor in a Patient With Familial Paraganglioma Syndrome Type 4

OBJECTIVE: Familial paraganglioma syndrome type 4 is associated with mutations in the succinate dehydrogenase complex subunit B (SDHB) gene. We report the case of a patient with familial paraganglioma syndrome type 4 with the mutation c.600G>T; p.Trp200Cys who developed a gastric gastrointestinal stromal tumor (GIST) with a KIT mutation. METHODS: Clinical, radiographic, and genetic data have been presented. RESULTS: A 40-year-old man with familial paraganglioma syndrome type 4 and recurrent paraganglioma presented with epigastric pain. He had undergone resection of a paraganglioma superior to the right adrenal gland at 19 years of age, resection of two para-aortic paragangliomas at 39 years, and resection of a paraganglioma in the interatrial septum at 40 years. Computed tomography scan showed a 3.2 × 3.8-cm gastric body intraluminal polypoid mass. A partial gastrectomy was performed, which revealed a GIST with a KIT mutation (NM_000222.2[KIT]:c.2466T>A[p.Asn822Lys]). CONCLUSION: This case provides further evidence that mutations in SDHB and KIT are not mutually exclusive with GISTs. It also identifies the need for endoscopic evaluation for GIST in patients with familial paraganglioma syndrome type 4 with unexplained gastrointestinal symptoms.