Intratumoral calcifications in pancreatic neoplasms on unenhanced CT: frequency and diagnostic implications

Serous cystadenomas (SCAs), solid pseudopapillary neoplasms (SPNs), neuroendocrine neoplasms (NENs), and mucinous cystic neoplasms (MCNs) are pancreatic tumors that frequently develop calcifications. Identifying the presence and pattern of calcifications on unenhanced CT scans can significantly aid radiologists in differential diagnosis.

Patients were included if they had a confirmed diagnosis through pathology or endoscopic ultrasound and MRI follow-up for at least one year. Exclusion criteria were the absence of CT imaging and multiple pancreatic lesions. Two radiologists independently reviewed unenhanced CT scans to assess lesion location, size, presence of calcifications, and calcification patterns, categorized as Type 1 (punctate), Type 2 (curvilinear/elongated), and Type 3 (coarse). Statistical analysis was performed using Fisher's test for categorical variables, Kruskal-Wallis and Mann-Whitney tests for numerical variables, and logistic regression models to assess the impact of calcification patterns on diagnosis. Sensitivity, specificity, accuracy, and AUC-ROC were calculated for predictive models.

311 patients (mean age 61 ± 14 years; 56.9% female) were included. Calcifications were present in 27.7% of cases. Calcified NENs and SPNs were more frequently in the body/tail (p = 0.003), and calcified NENs were larger than non-calcified ones (p < 0.001). Punctate calcifications were most common in NENs, while coarse calcifications predominated in SCAs, decreasing the likelihood of a NEN diagnosis and increasing the probability of SCA. The AUC-ROC values were 0.891 for NENs and 0.986 for SCAs.

Approximately 30% of pancreatic tumors exhibit calcifications. Punctate intratumoral calcifications are more indicative of NENs, whereas coarse calcifications strongly suggest SCAs, influencing the differential diagnosis.