¹⁸F-fluorodeoxyglucose PET/CT features and correlations with histopathologic characteristics in sclerosing epithelioid fibrosarcoma

Abstract

Sclerosing epithelioid fibrosarcoma (SEF) is a clinicopathologically distinct variant of fibrosarcoma that is capable of recurrence and metastasis. Awareness of imaging features and histopathologic characteristics will be helpful for differential diagnosis from other common tumors. Here, we report a case of SEF metastasizing to the pancreas as a solitary mass mimicking primary pancreatic cancer, and summarize the reported cases with FDG PET/CT from the literature (n=4). PET/CT showed abnormal FDG accumulation (n=2), mild FDG uptake (n=1), or photopenic (n=1). The FDG PET/CT features are closely related to histopathologic characteristics regarding its differentiation and aggressiveness.

Keywords: FDG; PET/CT; Sclerosing epitheloid fibrosarcoma; pancreas.

Figure 1

A. Portal venous phase of contrast enhanced CT shows a light enhanced mass in the head of the pancreas. B. Curved planar reformation shows the mass is adjacent to the portal vein without gross invasion. C. The distal pancreatic duct is obviously dilated. D, E. Mild FDG signal within the mass in PET/CT scan.

Figure 2

A, B. The tumor is composed of small to medium size epithelioid cells with pale or clear cytoplasm. The tumor cells are arranged in nests, cords and clusters, and are embedded in a dense hyalinized collagenous matrix. C. The tumor cells show diffuse and strong reactivity for vimentin. D. Ki-67 labeling index is 15%.