Diffuse pancreatic parenchymal atrophy, an imaging finding predictive of the development of pancreatic ductal adenocarcinoma: A case-control study

Abstract

Background and aim: Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer, partly because its early detection is difficult. This study aimed to identify computed tomography (CT) findings associated with PDAC prior to diagnosis.

Methods: Past CT images were retrospectively collected from the PDAC group (n = 54) and the control group (n = 90). The following imaging findings were compared: pancreatic mass, main pancreatic duct (MPD) dilatation with or without cutoff, cyst, chronic pancreatitis with calcification, partial parenchymal atrophy (PPA), and diffuse parenchymal atrophy (DPA). In the PDAC group, CT findings were examined during the pre-diagnostic period and 6-36 months and 36-60 months before diagnosis. Multivariate analyses were performed using logistic regression.

Results: MPD dilatation with cutoff (P < 0.0001) and PPA (P = 0.023) were identified as significant imaging findings 6-36 months before diagnosis. DPA was identified as a novel imaging finding at 6-36 months (P = 0.003) and 36-60 months (P = 0.009) before diagnosis.

Conclusion: DPA, MPD dilatation with cutoff, and PPA were identified as imaging findings associated with pre-diagnostic PDAC.

Keywords: computed tomography; main pancreatic duct; pancreatic cancer; pancreatic ductal adenocarcinoma; pancreatic parenchymal atrophy.

Figure 1

Study flow chart. CT, computed tomography, PDAC, pancreatic ductal adenocarcinoma. *1: Eleven patients belonged to both groups since they underwent CT examinations in both periods. *2: Eight patients belonged to both groups.

Figure 2

(a) Changes in the prevalence of computed tomography (CT) findings associated with cyst and main pancreatic duct (MPD) dilatation. The prevalence of cyst, MPD dilatation without cutoff, and MPD dilatation with cutoff for each time period (36–60 months, 18–36 months, and 6–18 months before diagnosis and time of diagnosis) is shown. The prevalence of cyst and MPD dilatation with cutoff increased from 36 months before diagnosis to the time of diagnosis. (b) Changes in the prevalence of CT findings associated with parenchymal atrophy. The prevalence of parenchymal atrophy (diffuse parenchymal atrophy [DPA], focal parenchymal atrophy [FPA], or upper parenchymal atrophy [UPA]) for each time period (36–60 months, 18–36 months, and 6–18 months before diagnosis and time of diagnosis) is shown. The prevalence of UPA was highest at the time of diagnosis. The prevalence of FPA and DPA was similar before diagnosis, and the prevalence of both was lower at the time of diagnosis. M, months. (a): , Cyst; , MPD dilatation without cutoff; , MPD dilatation with cutoff. (b): , DPA; , FPA; , UPA.

Figure 3

Typical cases with diffuse parenchymal atrophy in the pancreatic ductal adenocarcinoma (PDAC) group on past computed tomography (CT) images and CT images at diagnosis. (a) CT images of a 75‐year‐old female at 30 months prior to the diagnosis (left panels) and at the time of diagnosis (right panels). PDAC developed in the body of the pancreas. (b) CT images of a 73‐year‐old male at 43 months prior to the diagnosis (left panels) and at the time of diagnosis (right panels). PDAC developed in the head of the pancreas. (c) CT images of a 71‐year‐old female at 35 months prior to the diagnosis (left panels) and at the time of diagnosis (right panels). PDAC developed in the tail of the pancreas. The yellow arrows indicate PDAC.

Figure 4

Histopathology of diffuse parenchymal atroph (DPA). A 71‐year‐old woman with DPA developed pancreatic ductal adenocarcinoma (PDAC) in the pancreatic tail. (a) A loupe image of hematoxylin and eosin‐stained sections of a resected specimen in the noncancerous portion of the pancreatic body, which was taken from about 2.5 cm away from the lesion. An arrow indicates the main pancreatic duct. (b) Interlobular fatty deposit and mild fibrosis (arrow heads) are shown in a low magnified view. An arrow indicates the main pancreatic duct. (c) Interlobular fatty infiltrations are seen under high magnification. However, these findings were not specific findings shown in the noncancerous portion of PDA but sometimes shown in the noncancerous portion of PDAC developed in elderly people.