Pleomorphic Adenoma Versus Warthin Tumor of the Parotid Gland: Diagnostic Value of CT Perfusion Imaging and Its Pathologic Explanation

Abstract

AIM: To investigate the value of CT perfusion (CTP) imaging in the differentiation of pleomorphic adenoma and warthin tumor deriving singly from the parotid gland, and to explain its pathological basis. Methods: CTP was successfully performed in 29 patients with parotid tumors whose diagnoses were confirmed by surgery or biopsy. Data were postprocessed by using the Philips EBW workstation and analyzed using a dynamic analysis module. Postprocessing-generated a tissue time-density curve (TDC) and maps showed blood flow (BF), blood volume (BV), time-to-peak (TTP) and peak enhancement index (PEI). Independent-sample test and receiver operating characteristic (ROC) curves were used to analyze the difference and diagnostic efficacies of all perfusion data between the tumors. HE dyeing pathological section of all tumors was obtained after operation. Results: Perfusion maps of all tumors were successfully obtained. TDC of pleomorphic adenomas mainly showed a gradually ascension, and warthin tumours showed a fast ascent followed by a fast descent. The BF, BV, PEI and TTP values were statistically significant different between the pleomorphic adenomas and warthin tumors (p < 0. 01). ROC demonstrated that BF, BV and PEI, except for TTP, had actual significant differences between these two tumor types. Warthin tumors contains rich capillary network, and with a high cellularity-stromal grade. With regard to pleomorphic adenomas, it had less angiogenesis, but abundant muciform and chondroid tissue. Conclusions: CTP could provide TDC and perfusion data, which is feasible to differentiate pleomorphic adenomas from Warthin tumors, and could reflect tumors histopathological feature.