Decidualization of ovarian endometriosis during pregnancy mimicking malignancy.

OBJECTIVE: The purpose of this series is to present deciduosis (the formation of extrauterine decidua) as one of the differential diagnoses of a malignant tumor during pregnancy. METHODS: Two cases are described in which pregnant patients had a pelvic tumor. The lesions, which were diagnosed in the early second trimester, consisted of complex masses with an extensive blood supply and had a sonographic appearance of a malignant tumor. The high suspicion for malignancy necessitated surgical intervention. RESULTS: During surgery, the lesions were observed to be of an ovarian origin with papillary excrescences covering their exterior. The lesions were excised and sent for histologic examination. The results showed a markedly decidualized endometriotic cyst in both cases. CONCLUSIONS: This phenomenon is a diagnostic challenge and should be considered in the differential diagnosis of a malignant mass during pregnancy.

Diagnosis of pregnancy-associated uterine venous plexus thrombosis on the basis of transvaginal sonography.

OBJECTIVE: To describe the sonographic signs of uterine venous plexus thrombosis. METHODS: Four pregnant patients had a diagnosis of uterine venous plexus thrombosis in the first half of gestation. The diagnosis was based on transvaginal sonography only in 3 cases, and the fourth had magnetic resonance imaging corroboration. RESULTS: All 4 patients had similar sonographic features of uterine venous plexus thrombosis on transvaginal sonographic examination. The thrombi within the dilated veins were shown as elongated echogenic structures along the lumen that appeared round on transverse views of the affected veins. They showed swinging movements provoked by gentle transducer pressure. Power and color Doppler sonography enhanced the uterine venous plexus thrombosis diagnosis by showing blood flow around the thrombi. There were no signs of thromboembolic disease. Sonographic findings in deep leg veins and iliac veins were normal in all cases. Complete thrombophilia studies did not reveal any abnormalities. The uterine venous plexus thrombosis could not be detected on transabdominal sonography and was shown better by transvaginal sonography compared with magnetic resonance imaging. During 3 months of anticoagulation therapy, the thrombi gradually disappeared in all cases. CONCLUSIONS: Focusing on the pelvic veins while performing a transvaginal sonographic study during pregnancy may reveal important findings, which may have clinical implications. The therapeutic treatment of uterine venous plexus thrombosis is controversial and still empirical.