Gray scale ultrasound feature typing of metastasis in the ovary, especially signet-ring cell carcinoma

Abstract Background To describe the gray scale ultrasound features of metastatic ovarian tumors on the basis of the origin of the primary tumor in a large study population. This retrospective study included 112 patients with 188 histopathologically confirmed metastatic ovarian tumors. Among the patients, 102 were detected with 143 masses via ultrasonography. Patient age, mass bilaterality, maximum tumor diameter and ultrasound image character were recorded. Results Ultrasound images were classified into three subtypes: (type A) multilocular-solid, (type B) purely solid, and (type C) solid with several round or oval cysts. The metastatic tumors in the ovaries were mostly bilateral but had a lower rate of bilaterality when detected by ultrasound. Breast cancer metastasis had the highest misdetection rate (69.6%) because its focal metastasis could only be recognized by histology or immunohistochemistry. Stomach was the most common origin of metastasis: 45.7% and 51.0% via pathology and ultrasonography, respectively. Metastases that originated from colon mostly belonged to type A (65.9%) and closely mimicked primary epithelial ovarian tumor morphologically. Metastases that originated from stomach predominantly belonged to types B (31.9%) and C (58.3%). Signet-ring cell carcinoma (SRCC) corresponded to types B and C only regardless of its origin. Conclusions The novel typing method developed herein provides more vivid images for classifying ovary metastasis compared with existing typing methods.