CT features of low grade serous carcinoma of the ovary

OBJECTIVE: To evaluate the CT features of pathologically proven low grade serous carcinoma (LGSC) of the ovary. METHODS: Patients with a pathologic diagnosis of LGSC and CT prior to oophorectomy were retrospectively identified. The CT scans in 14 patients were available and were analyzed for an adnexal mass, peritoneal mass and ascites. The adnexal mass was characterized as complex primarily cystic, mixed cystic solid, or primarily solid. Calcification in the adnexal and peritoneal masses and nodes was noted. RESULTS: Pathology revealed 6 patients had LGSC and 8 patients had a combined diagnosis of LGSC and serous borderline tumor (SBT) of the ovary. Of the 6 patients with only LGSC, 4 had primarily solid or mixed solid cystic adnexal masses and 5 had peritoneal masses. Calcification was present in the adnexal and peritoneal masses in 4 patients, and in nodes in 2 patients. Of the 8 patients with co-existing LGSC and SBT, 7 had complex primarily cystic adnexal masses and 6 had peritoneal masses. Calcification was present in the adnexal and peritoneal masses in 5 patients and in nodes in 2 patients. CONCLUSION: LGSC can appear as a solid, mixed solid cystic, or complex primarily cystic ovarian mass, and the appearance may be due to a co-existing SBT. Calcification of the adnexal and peritoneal masses appears to be common. LGSC is a diagnostic consideration in patients with a calcified adnexal mass and concurrent peritoneal masses or calcified nodes on CT.