Beautiful and regular vascularization in a borderline ovarian seromucinous tumor detected by microvascular imaging

A 35-year-old female patient was admitted due to elevated tumor markers for 17 days. Seventeen days ago, the patient underwent a physical examination, which revealed a serum CA125 of 339.8 U/ml and a serum CA199 of > 2000 U/ml. Anal examination revealed a right adnexal mass measuring 6 × 5 cm with well-defined margins. The patient had no nausea, vomiting, abdominal pain, bloating or abnormal vaginal bleeding. Contrast-enhanced computed tomography (CT) showed a mass in the right adnexa with a size of 6.3 × 4.5 cm with no lymph node enlargement in the pelvic cavity, considered an ovarian epithelial tumor. Transrectal ultrasonography [Figure 1 A] and three-dimensional (3D) transrectal ultrasound [Figure 1 B] showed a cystic-solid mass measuring 6.2 × 5.3 × 3.5 cm in the right adnexa, with regular morphology, clear boundary, poor translucency, and papillary projections on the wall (3.0 × 2.5 × 1.5 cm), and the ovarian tissue was visible encircling its periphery in the form of “crescent sign”. Microvascular imaging [Figure 1 C] and 3D microvascular imaging [Figure 1 D] showed bifurcation of blood flow into papillary projections, regularly distributed along the axis of the papillary trunk and branches, considered a SMBT. Ovarian mass was removed by laparotomy. Intraoperative findings included a 6 cm cyst in the right ovary with a smooth surface [Figure 1 E] and the cut surface of the cyst showed papillary projections and brownish gelatinous cystic fluid [Figure 1 F]. Besides, a 5 mm brown nodule was seen on the surface of the sacral ligament. Postoperative pathology confirmed an SMBT and ectopic endometrial foci. Immunohistochemistry showed ER (+), PR (partial +), PAX-8 (+), P53 (wild-type expression), Ki-67 (index 5%), WT-1 (-), Villin (-), P16 (partial +), MUC6 (partial +), CA-125 (+). Fig. 1 Borderline Ovarian Seromucinous Tumor. Transrectal ultrasound ( A ) and three-dimensional ultrasound ( B ) show a cystic-solid mass in the right adnexa with regular morphology, clear border, poor translucency, and papillary protrusions on the wall. Microvascular imaging ( C ) and three-dimensional microvascular imaging ( D ) show bifurcation of blood flow into papillary projections, regularly distributed along the axis of the papillary trunk and branches. Intraoperative findings ( E ) include a cyst with a smooth surface and the cut surface of the cyst ( F ) shows papillary projections and brownish gelatinous cystic fluid Borderline Ovarian Seromucinous Tumor. Transrectal ultrasound ( A ) and three-dimensional ultrasound ( B ) show a cystic-solid mass in the right adnexa with regular morphology, clear border, poor translucency, and papillary protrusions on the wall. Microvascular imaging ( C ) and three-dimensional microvascular imaging ( D ) show bifurcation of blood flow into papillary projections, regularly distributed along the axis of the papillary trunk and branches. Intraoperative findings ( E ) include a cyst with a smooth surface and the cut surface of the cyst ( F ) shows papillary projections and brownish gelatinous cystic fluid

Pathologically, SMBTs consist of papillae with stratified branches surrounded by an edematous fibrous matrix [ 2 ]. A cyst with septa, solid component(s), mural nodules, and blood vessels in the papillary projections are characteristic of SMBTs on imaging [ 3 ]. SMBTs can present similarly to serous borderline tumours, and differentiation lies in the origin of the endometriotic cysts [ 4 , 5 ]. In our case, the SMBT showed a cyst with mural nodules, poor translucency, and blood vessels in the mural nodules. Moreover, microvascular imaging, particularly 3D microvascular imaging of ultrasound showed the regular distribution of vascularity along the axis of the papillary trunk and branches. The ultrasound distribution of the blood flow was consistent with the microscopic characteristics of the SMBT. Microvascular imaging helped detect very slow flow, especially in small vessels, improve identify vascularity distribution in the papillary of SMBT, and may improve our ability to differentiate SMBTs.

In 2014, a new pathological classification of borderline seromucinous ovarian tumor (SMBT) was included in the World Health Organization (WHO) classifications [ 1 ]. SMBTs are considered to be an endometriosis-related ovarian neoplasm and, unlike other types of borderline tumours, endometriosis is found in about 30–70% of ovarian SMBTs. In clinical practice, SMBT is still hard to differentiate preoperatively on ultrasound. We presented a case of SMBT, in which microvascular imaging of ultrasound helped in the diagnosis.