68Ga-DOTATOC PET/CT Imaging of a Muscular Solitary Fibrous Tumor

A 73-year-old woman was referred for Ga-68-DOTATOC PET/CT staging of a grade 2 pancreatic neuroendocrine tumor, which showed the primary pancreatic tumor, liver metastases, one left pleural metastasis, and high uptake in a mass of the right triceps brachii muscle. Two years before, she underwent F-18-FDG PET/CT and In-111-pentetreotide scan, respectively, with low and high uptake of each radiotracer in the triceps mass. Histopathological analysis revealed a solitary fibrous tumor. Immunohistochemistry showed no staining for SSTR-2 and SSTR-5, suggesting tumor overexpression of another somatostatin receptor. This case highlighted a potential pitfall on Ga-68-DOTATOC PET/CT.

Automated summary

A 73-year-old woman with a grade 2 pancreatic neuroendocrine tumor underwent Ga-68-DOTATOC PET/CT staging, revealing primary pancreatic tumor, liver and pleural metastases, and high uptake in a triceps muscle mass. Previous F-18-FDG PET/CT and In-111-pentetreotide scans showed low and high uptake in the triceps mass, respectively. The histopathological analysis identified a solitary fibrous tumor with no staining for SSTR-2 and SSTR-5, indicating overexpression of another somatostatin receptor. This case highlights a potential pitfall in Ga-68-DOTATOC PET/CT.