Epstein E, et al. - Researchers aimed at delineating the sonographic characteristics of post‐molar gestational trophoblastic neoplasia (GTN) at diagnosis and during follow‐up. In addition, they determine their correlation with methotrexate (MTX) resistance (R) as first‐line chemotherapy. They analyzed a total of 36 women who were treated for post‐molar GTN and had undergone expert transvaginal ultrasound assessment ≤ 2 weeks prior to, or ≤ 1 week after, the start of first‐line MTX treatment. Seventy-eight percent of women with post‐molar GTN were detected to have uterine lesions at the time of diagnosis. Focal lesions were observed in 24 (67%) women and global lesions in four (11%) women. Median maximum lesion diameter of 40.4 mm was inscribed; a color score of 3 or 4 was reported for 26/28 (93%) lesions. Arteriovenous fistulas were identified in 9/28 (32%) women and theca lutein cysts in 4/36 (11%) women. Complete resolution of the vast majority of the lesions occurred during follow‐up, after a median of 7 months. In uterine tumors of 4 cm, or larger, and in global lesions, MTX‐R was more frequently observed.