Diagnostic Approach to Benign and Malignant Calcifications in the Abdomen and Pelvis.

Intra-abdominal calcifications are common. Multiple pathologic processes manifest within the abdomen and pelvis in association with calcifications, which can be benign, premalignant, or malignant. Although calcium deposition in the abdomen can occur secondary to various mechanisms, the most common cau se is cellular injury that leads to dystrophic calcifications. The authors provide a summary of various common and uncommon calcifications in the abdomen and pelvis, primarily using location to illuminate diagnostic significance. Six broad categories of calcifications in the abdomen and pelvis are recognized: mesenteric, peritoneal, retroperitoneal, organ-based, vascular, and musculoskeletal. In addition to site, the various patterns and morphology of calcifications encountered in various conditions can be helpful for diagnosis, especially those depicted on radiographs. For example, some patterns diagnostic for various conditions include round or oval stones in the biliary or urothelial tracts, curvilinear calcifications associated with cysts or neoplasms, and sheetlike calcifications along peritoneal surfaces in the setting of chronic peritoneal dialysis or metastatic disease. Organ encrustation with calcium may be a premalignant finding (eg, porcelain gallbladder). In addition, the development of calcium after initiation of treatment can be used as an indicator of response in conditions such as tuberculosis, lymphoma, and hydatid disease. As calcifications are almost invariably detected at imaging, it is imperative for radiologists to be aware of their diagnostic implications and use the presence of calcification in an organ, mass, or other anatomic location for problem solving. RSNA, 2020.