Utility of CT to Differentiate Pancreatic Parenchymal Metastasis from Pancreatic Ductal Adenocarcinoma

Abstract

Purpose: To report the computed tomography (CT) features of pancreatic parenchymal metastasis (PPM) and identify CT features that may help discriminate between PPM and pancreatic ductal adenocarcinoma (PDAC). Materials and methods: Thirty-four patients (24 men, 12 women; mean age, 63.3 ± 10.2 [SD] years) with CT and histopathologically proven PPM were analyzed by two independent readers and compared to 34 patients with PDAC. Diagnosis performances of each variable for the diagnosis of PPM against PDAC were calculated. Univariable and multivariable analyses were performed. A nomogram was developed to diagnose PPM against PDAC. Results: PPM mostly presented as single (34/34; 100%), enhancing (34/34; 100%), solid (27/34; 79%) pancreatic lesion without visible associated lymph nodes (24/34; 71%) and no Wirsung duct enlargement (29/34; 85%). At multivariable analysis, well-defined margins (OR, 6.64; 95% CI: 1.47–29.93; p = 0.014), maximal enhancement during arterial phase (OR, 6.15; 95% CI: 1.13–33.51; p = 0.036), no vessel involvement (OR, 7.19; 95% CI: 1.512–34.14) and no Wirsung duct dilatation (OR, 10.63; 95% CI: 2.27–49.91) were independently associated with PPM. The nomogram yielded an AUC of 0.92 (95% CI: 0.85–0.98) for the diagnosis of PPM vs. PDAC. Conclusion: CT findings may help discriminate between PPM and PDAC.

A nomogram diagnostic prediction model of pancreatic metastases of small cell lung carcinoma based on clinical characteristics, radiological features and biomarkers

“…Multivariate logistic regression analyses were performed to obtain six radiological features for PM-SCLC diagnosis in CT imaging model or combined model ( Tables 4 , 5 ). The six radiological features were all independent risk factors, including pancreatic duct dilatation, pushed pancreatic duct, tumor size, parenchymal atrophy, vascular involvement and enhancement type, which were similar to those reported in previous studies ( 18 , 26 , 41 ). Although pancreatic duct dilatation wasn’t obtained into the combined model, both Galia, et al.…”

“…( 18 ) and Barat, et al. ( 26 ) confirmed that absence of pancreatic duct dilatation were the discriminating features for the diagnosis of PM-SCLC against PDAC. In our analysis, pushed pancreatic duct was another independent predictor not obtained into the combined model and not reported in previous studies, but presence of pushed pancreatic duct accounted for 35.5% (33/93) of PM-SCLC and 0.4% (1/206) of PDCA in our datasets.…”

“…Barat, et al. ( 26 ) showed that no differences in largest tumor diameter were found between PM (35.0 ± 21.1 mm) and PDAC (32.1 ± 9.2 mm). In the Tsitoutridis et al.…”

“…Pancreatic metastasis of lung cancer is rare, accounting for less than 2% of all pancreatic malignancies ( 24 , 29 ), the majority being small-cell lung carcinoma (SCLC) ( 25 ). In previous studies on the differential diagnosis of PM from PDAC ( 18 , 26 ), in addition to small cell lung cancer, the primary tumors of these metastases also included non-small cell lung cancer, renal carcinoma, breast cancer, melanoma, gastrointestinal cancer, sarcoma ( 28 ). However, the characteristics of these PM depended on the primary tumor and were shown to be single, multiple, or diffuse, hypovascular or hypervascular on CT or MRI.…”

“…The variables of CT imaging were as follows: tumor size (maximum diameter on axial images, the unit is mm), number (one, two, equal to or more than three lesions in the pancreas), location (head, neck, body or tail), tumor shape (round, lobulated or irregular), necrosis (presence or absence), margin (well-defined or ill-defined), parenchymal atrophy (presence or absence), retention cyst (presence or absence), peripancreatic fluid (presence or absence), vascular involvement [presence or absence), common bile duct dilatation (> 8 mm ( 25 )], pancreatic duct through (presence or absence), pancreatic duct dilatation (≥ 3 mm ( 26 )), pushed pancreatic duct (presence or absence), coeliac enlarged lymph nodes [short-axis diameter was larger than 10 mm or included necrosis of any size ( 27 , 28 )], peritumoral lymph nodes (none, 0<SD<8mm, SD≥8mm), relative density (low density, iso density, high density), blood supply (poor, rich), enhancement pattern (homogeneous, heterogeneous), enhancement degree (none, mild, moderate, strong), enhancement type (gradual, fast forward and backward, other), enhancement type1 (circular, overall, partial).…”