Pancreatic sarcomatoid carcinoma: CT, MRI, and ¹⁸F-FDG PET/CT features

To investigate computed tomography (CT), magnetic resonance imaging (MRI), and combined 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron-emission tomography (PET)/CT features of pancreatic sarcomatoid carcinoma (PSC).

The hospital database was searched retrospectively for the patients with PSC confirmed at histopathology after surgery. Ten patients who underwent unenhanced and enhanced CT (n=4), unenhanced and enhanced MRI (n=2), ¹⁸F-FDG PET/CT (n=2), and both enhanced CT and ¹⁸F-FDG PET/CT (n=2) were enrolled. Two patients underwent additional delayed PET/CT. The maximum standardised uptake value (SUVmax) was measured on PET/CT images.

Eleven lesions were detected in 10 patients. Solid and cystic components (n=6), intratumoural haemorrhage (n=1), nodular calcification (n=2), main pancreatic duct dilatation resulted from lesion obstruction (n=5) or compression (n=3), cholangiectasis (n=5), vascular and peripheral organ invasion (n=5 and 6, respectively), hepatic and lymphatic metastases (n=4 and 2, respectively) were detected. All five lesions in four patients who underwent PET/CT showed intense FDG uptake on PET/CT with SUVmax (16, range 10.9-21.1). Increase of FDG uptake (SUVmax = 18.9, 20.1, and 27.3, respectively) was revealed on the delayed scan of three lesions in two patients.

PSCs were more commonly ill-defined solid cystic masses, which caused pancreatic duct obstruction/compression without pancreatic parenchymal atrophy, and these masses on PET/CT showed high FDG uptake on both initial and delayed PET/CT.