The 'lead vessel': a vascular ultrasound feature of metastasis in the ovaries.

OBJECTIVE: To investigate, in a series of metastatic and primary invasive ovarian lesions examined by color Doppler, the prevalence of a main peripheral vessel penetrating into the central part of the ovarian mass with a tree-shaped morphology, defined as the 'lead vessel'. METHODS: This was a retrospective study of 31 patients with histopathologically confirmed metastatic involvement of the ovary and 106 patients with confirmed primary invasive ovarian carcinoma, who had undergone standardized ultrasound examination, with established definitions of ultrasound characteristics. We retrieved sonographic images and videoclips, focusing on the detection of the lead vessel. RESULTS: The presence of the lead vessel was detected in 11/31 (35.4%) metastatic ovarian tumors, and in only two (0.01%) cases of primary ovarian carcinoma (P = 0.0001). At color Doppler analysis, metastatic ovarian lesions were characterized by significantly lower pulsatility index (P = 0.0001) and resistance index (P = 0.0001) values, and significantly higher peak systolic velocity (P = 0.0002) and time-averaged maximum velocity (P = 0.04) values, when compared with primary ovarian carcinomas. The lead vessel was detected in 11/21 (52%) solid metastatic lesions and in no cases of multilocular or multilocular-solid lesions (P = 0.008). CONCLUSION: The lead vessel is a novel sonographic feature of vascular morphology in solid ovarian metastases. The more frequent observation of this feature in metastatic ovarian tumors compared with primary invasive ovarian carcinomas warrants further investigation in order to explore its potential role in the diagnosis of metastatic ovarian masses.