Pitfalls in pancreatic imaging

Mimics of pancreatic neoplasms at cross-sectional imaging: Pearls for characterization and diagnostic work-up

Interpreting imaging examinations of the pancreas can be a challenge. Several different entities can mimic or mask pancreatic neoplasms, including normal anatomic variants, non-pancreatic lesions, and both acute and chronic pancreatitis. It is important to distinguish these entities from pancreatic neoplasms, as the management and prognosis of a pancreatic neoplasm, particularly adenocarcinoma, have considerable impact on patients. Normal pancreatic variants that mimic a focal lesion include focal fatty atrophy, annular pancreas, and ectopic pancreas. Extra-pancreatic lesions that can mimic a primary pancreatic neoplasm include vascular lesions, such as arteriovenous malformations and pseudoaneurysms, duodenal diverticula, and intra-pancreatic accessory spleen. Both acute and chronic pancreatitis can mimic or mask a pancreatic neoplasm and are also associated with pancreatic ductal adenocarcinoma. Awareness of these entities and their imaging features will enable the radiologist to narrow the differential diagnosis, provide recommendations that expedite diagnosis and avoid unnecessary work-up or delays in patient care.

Pancreatic surface morphology and its classification

Introduction: Anomalies and variants of development of the pancreas are relatively frequent. These variations can often lead to misdiagnosis and unnecessary medical procedures. Although, pancreatic diseases are a constantly researched field, fundamental research is relatively understudied and re-evaluation of the pancreatic morphology is performed rarely.

Aim: The goal of the current study was to analyse pancreatic surface morphology by means of macroscopic anatomical dissection of 78 organ complex.

Material and methods: The anatomy of the pancreas was studied by means of macroscopic anatomical dissection. The study was performed on 78 organ complexes (the pancreas, spleen, and duodenum with surrounding abdominal fat) donated to the department of human anatomy from patients who died of causes not related to pancreatic diseases. The organs were fixed in a 10% formalin solution separately to accurately preserve their forms. The organs were measured by a caliper.

Results: The lie of the pancreas was classified according to Kreel and co-workers into 6 types: oblique shape in 11.54% of cases, sigmoid – 30.77%, transverse – 25.64%, horseshoe – 11.54%, L-shaped – 14.1%, and inverted V shape in 5.13%. Moreover, there were two possible L-shapes, the classical (8.97%) and inverted L-shape (5.13%). In one case, the pancreas had an unusual M-shape (1.28%). One specimen was a case of short pancreas (1.28%). Surface clefts were encountered in 17.95% of cases and in 5.13% of these cases, there was a branch of the splenic artery.

Conclusions: The current study demonstrates variations in the lie of the pancreas as well as several new possible variants. Moreover, we propose a modified classification based on these findings. Therefore, the pancreas can have an oblique, sigmoid, transverse, horseshoe, L shape, inverted L, inverted V, and M shaped lie. Pancreatic clefts are another frequently encountered variation that should be kept in mind. The size of the pancreas alone is variable and should be analyzed together with its structure to avoid possible misinterpretation.