Introduction

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers, but diagnosis at an early stage can improve the prognosis. Focal parenchymal atrophy and main pancreatic duct (MPD) dilatation have been identified as early signs of PDAC through imaging studies. However, limited evidence exists regarding their temporal progression due to previous study limitations with restricted case numbers.

Aims & Methods

We aimed to ascertain a more precise frequency assessment of suspicious PDAC findings as well as delineate the temporal progression of them. A multicenter retrospective study was conducted on patients diagnosed with PDAC between 2015 and 2021. We included patients who had undergone at least one computed tomography (CT) scan ≥6 months before diagnosing PDAC. The temporal progression of suspicious PDAC findings on CT was investigated. As an additional relatively small control group analysis, we reviewed the CT findings of each 30 consecutive patients with chronic pancreatitis and autoimmune pancreatitis at our hospital between 2022 and 2023.

Results

Out of 1832 patients diagnosed with PDAC at 17 facilities, 320 had a previous CT before their diagnosis. Suspicious PDAC findings were detected in 153 cases (47.8%), with focal parenchymal atrophy being the most common (26.6%), followed by MPD dilatation (11.3%), pancreatic swelling or mass (6.9%), retention cysts (5.0%), pancreatic inflammation (3.8%), and MPD stricture (1.9%). Focal parenchymal atrophy was the earliest detectable sign among all suspicious findings and became visible on average 2.7 years before diagnosis, and the next most common, MPD dilatation, 1.1 years before diagnosis. Other findings were less frequent and appeared around 1 year before diagnosis. Focal parenchymal atrophy followed by MPD dilatation was observed in 10 patients but not in reverse order. Focal parenchymal atrophy was more frequently detected in the pancreatic body/tail. No significant relationship was found between the pathological PDAC differentiation or tumor stage and the time course of the CT findings. All cases of focal parenchymal atrophy progressed just prior to diagnosis, and the atrophic area was occupied by tumor at diagnosis. Main pancreatic duct dilatation continued to progress until diagnosis. In the study of the control group, among the patients with chronic pancreatitis, 96.7% (29/30) exhibited diffuse pancreatic atrophy, while focal pancreatic atrophy was observed in 3.3% (1/30) in the body of the pancreas. There was no significant progression of focal pancreatic atrophy observed in chronic pancreatitis patient. Among the patients with autoimmune pancreatitis, pancreatic atrophy was identified in 90% (27/30), and all instances of atrophy observed in diffuse pancreatic parenchyma.

Conclusion

This large-scale study revealed that the temporal progression of focal parenchymal atrophy is the earliest detectable sign indicating PDAC. The morphology of the atrophy and whether it is progressive or not are important factors in distinguishing pancreatic atrophy with malignancy from that with benign lesion. These results provide crucial insights for early PDAC detection.

Clinical Case Summary

Colonoscopy is an essential tool in the diagnosis and management of various gastrointestinal disorders, yet it carries a risk of complications that can complicate patient care. Among these, post-colonoscopy appendicitis represents a rare but critical condition. The interplay between colonoscopy-induced inflammation and pre-existing appendiceal pathology may contribute to this phenomenon. A thorough understanding of the pathophysiology, clinical manifestations, and management strategies associated with post-colonoscopy appendicitis is vital for healthcare professionals to enhance early recognition and optimize patient outcomes.
A sixty-one-year-old female patient underwent esophagogastroduodenoscopy(EGD) and colonoscopy due to recurrent episodes of diffuse, non-radiating mild abdominal pain, as well as for colorectal cancer screening. The procedure was conducted without complications, but the bowel preparation was deemed inadequate (BBPS: 1-2-1). Twenty-four hours later, the patient presented to the emergency department, reporting severe diffuse non-radiating abdominal pain accompanied by multiple episodes of vomiting, nausea, and watery non-bloody diarrhea. Computed tomography of the abdomen was performed showing acute appendicitis. Subsequently, open appendectomy was performed with a course of intravenous antibiotics and patient then discharged home in good physical condition.
In conclusion, this case highlights the potential for post-colonoscopy appendicitis as a rare but significant complication that can arise following gastrointestinal procedures. It underscores the importance of maintaining a high index of suspicion for appendicitis in patients presenting with abdominal symptoms after colonoscopy, facilitating timely diagnosis and treatment.

References

• Ali,Mohammad MD¹; Patel, Jigar MD²; Katz, Douglas MD²; Friedel, David MD³. Post-Colonoscopy Appendicitis: A Rare but Concerning Entity: 1548. American Journal of Gastroenterology 113():p S891, October 2018
• ASGE review of adverse events in colonoscopyKothari, Shivangi T. et al.
  Gastrointestinal Endoscopy, Volume 90, Issue 6, 863 - 876.e3