technetium-tc-99m-sulfur-colloid and Solitary-Fibrous-Tumors

Although FDG PET is increasingly used for the staging of many types of sarcoma, little has been written regarding the FDG PET imaging characteristics of solitary fibrous tumor. We report a patient undergoing FDG PET/CT surveillance for squamous cell carcinoma of the tongue who was incidentally found to have two soft tissue masses in the retroperitoneum and pancreatic tail. Due to their low degree of FDG avidity, they were followed conservatively for approximately one year as they gradually increased in size. Technetium-99m sulfur colloid SPECT helped confirm that the pancreatic tail mass was not a splenule, after which both lesions were surgically resected and found to be extrathoracic solitary fibrous tumors without malignant features. These findings suggest that, as with other low-grade sarcomas, benign extrathoracic solitary fibrous tumors exhibit relatively little glycolytic metabolism in vivo.

Topics: Carcinoma, Squamous Cell; Fluorodeoxyglucose F18; Humans; Incidental Findings; Male; Middle Aged; Multimodal Imaging; Neoplasms, Multiple Primary; Pancreatic Neoplasms; Positron-Emission Tomography; Radiopharmaceuticals; Retroperitoneal Neoplasms; Solitary Fibrous Tumors; Technetium Tc 99m Sulfur Colloid; Tomography, X-Ray Computed; Tongue Neoplasms