Improvement of the Diagnosis of Isoattenuating Pancreatic Carcinomas by Defining Their Characteristics on Contrast Enhanced Computed Tomography and Endosonography with Fine-Needle Aspiration (EUS-FNA)

Abstract

(1) Background. The aim was to define typical features of isoattenuating pancreatic carcinomas on computed tomography (CT) and endosonography and determine the yield of fine-needle aspiration endosonography (EUS-FNA) in their diagnosis. (2) Methods. One hundred and seventy-three patients with pancreatic carcinomas underwent multiphase contrast-enhanced CT followed by EUS-FNA at the time of diagnosis. Secondary signs on CT, size and location on EUS, and the yield of EUS-FNA in isoattenuating and hypoattenuating pancreatic cancer, were evaluated. (3) Results. Isoattenuating pancreatic carcinomas occurred in 12.1% of patients. Secondary signs of isoattenuating pancreatic carcinomas on CT were present in 95.2% cases and included dilatation of the pancreatic duct and/or the common bile duct (85.7%), interruption of the pancreatic duct (76.2%), abnormal pancreatic contour (33.3%), and atrophy of the distal parenchyma (9.5%) Compared to hypoattenuating pancreatic carcinomas, isoattenuating carcinomas were more often localized in the pancreatic head (100% vs. 59.2%; p < 0.001). In ROC (receiver operating characteristic) analysis, the optimal cut-off value for the size of isoattenuating carcinomas on EUS was ≤ 25 mm (AUC = 0.898). The sensitivity of EUS-FNA in confirmation of isoattenuating and hypoattenuating pancreatic cancer were 90.5% and 92.8% (p = 0.886). (4) Conclusions. Isoattenuating pancreatic head carcinoma can be revealed by indirect signs on CT and confirmed with high sensitivity by EUS-FNA.

The role of abdominal ultrasonography in patients with isoattenuating pancreatic carcinoma

“…Histology was the gold standard for the final diagnosis in operated patients 9 . In patients without surgical treatment, the diagnosis of pancreatic carcinoma was based on positive cytology from EUS-FNA or ERCP (endoscopic retrograde cholangiopancreatography)-guided brushings and concurrent clinical and radiographic disease progression during 1-year follow-up.…”

“…Isoattenuating pancreatic carcinomas have almost twice the chance of surgical treatment than hypoattenuating carcinomas 9 . It is therefore very important to diagnose these isoattenuating tumours correctly and early, at a stage when surgical treatment is still possible 8,10 .…”

“…A possible diagnostic problem is isoattenuating pancreatic carcinoma, which cannot be directly visualised on contrast-enhanced CT. In isoattenuating pancreatic carcinoma, the difference in attenuation between the area of the suspected tumour and surrounding parenchyma is usually less than 10-15 HU (Hounsfield Units) and only the secondary signs are present [7][8][9] . The reported incidence of isoattenuating pancreatic carcinomas on CT is 5.4-14% (ref.…”

“…There are only a few studies on radiologically defined isoattenuating pancreatic carcinoma [7][8][9][13][14][15][16] . To date, only the sensitivity of MRI, PET (positron emission tomography) / CT (ref.…”

“…8 ) and EUS with fine-needle aspiration (FNA) (ref. 9 ) in isoattenuating pancreatic carcinoma has been examined. To our knowledge, the sensitivity of abdominal ultrasonography (US) in the diagnosis of isoattenuating pancreatic carcinoma has not yet been evaluated in detail.…”