A total of 188 pathologically metastatic ovary masses in 112 patients were considered for analysis. Their primary tumor histological diagnoses were from stomach, colon, breast, uterus, liver–pancreas–biliary tract (LPB), appendix, lungs, and kidneys (Table 1). Metastasis was identified before primary tumor in 12 patients. Metastasis and primary tumor were simultaneously identified in 16 patients. The rest interval between diagnosis of a primary carcinoma and subsequent discovery of ovarian involvement ranged from 1 month to 186 months (28.2±33.2 months) (Table 2). Among them, 143 masses in 102 patients were detected by ultrasonography, but 45 masses in 38 patients were misdetected. The most common origin was stomach: 45.7% and 51.0% via pathology and ultrasonography, respectively. Breast origin had the highest misdetection rate (69.6%). In the misdetection group, unilateral misdetection of bilateral metastasis was found in 31 patients, unilateral misdetection of unilateral metastasis in 2 patients, and bilateral misdetection of bilateral metastasis in 6 patients. No significant difference in age was observed between ultrasonography-detected and ultrasonography-misdetected groups. The maximum tumor diameter of the ultrasonography-misdetected group was significantly smaller than that of the ultrasonography-detected group (p < 0.05) (Table 3).
Except for 1 uterus endometrial stromal sarcoma and 1 uterus neuroendocrine carcinoma, the masses in the ultrasonography-detected group were classified into adenocarcinoma, including 73 gastric adenocarcinomas, 42 colorectal adenocarcinomas, 6 breast invasive ductal carcinomas, 1 invasive lobular carcinoma, 2 cervical adenocarcinomas, 2 uterus endometrial adenocarcinomas, 6 appendicular adenocarcinomas, 2 lung adenocarcinomas, 2 renal clear cell carcinomas, 3 pancreatic ductal adenocarcinomas, 2 gallbladder adenocarcinomas, and 2 cholangiocarcinomas.
The masses detected by ultrasonography were classified into three subtypes (Figure 1): (Type A) multilocular–solid similar to primary epithelial ovarian tumor with variable solid and cystic component ratio and the cystic component of good ultrasound penetration; (Type B) purely solid with inner echo that can be uniform or irregular in some cases as its mass volume is big; (Type C) solid with one or several round or oval cysts that are plump, with a smooth wall, superior transparency and of variable number, size, and position (Figure 2). Their shape is mostly regular or irregular or polylobate in some cases as its mass volume is big or adhered to peripheral tissues.
We noticed that the masses that originated from colon were mostly multilocular–solid (Type A; 29/44, 65.9%). Those that originated from stomach were mostly solid and could be classified as Types B (23/72, 31.9%) and C (42/72, 58.3%) (65/72 in total, 90.3%). Furthermore, we found 62 SRCC cases, including 18 Krukenberg cases (arbitrarily defined as >10% component of signet-ring cells). Their ultrasonography image features could be classified into Types B and C only regardless of their origin (stomach, colon, gall bladder, and appendix) (Table 4).