Can the two main cystic neoplasms of the pancreas be differentiated sonographically?
Serous, or microcystic, cystadenoma is a multilocular cystic lesion comprised of cystic foci measuring from <1 mm up to 2 cm. There can be a central scar with or without calcification. The sonographic appearance can vary depending on the size of the cystic foci from a slightly echogenic solid-appearing mass when all the cystic foci are small to a solid-appearing mass with cystic spaces. The central scar is echogenic on US. This lesion is benign, is most commonly seen in women >60 years, and most commonly occurs within the pancreatic tail.
Mucinous, or macrocystic, cystadenomas and cystadenocarcinomas are unilocular or multilocular cystic lesions with occasional papillary projections or calcifications. The cystic foci are usually >2 cm in size and fewer than 6 in number. On US, these cystic lesions are typically well circumscribed, with variable wall thickness and variable cystic foci size and contents (anechoic fluid, echogenic debris, mural vegetations, or solid components). These lesions are malignant or potentially malignant, are most commonly seen in middle-aged women, and most commonly occur in the pancreatic body or tail.