Ultrasound features of highly vascularized uterine myomas (uterine smooth muscle tumors) and correlation with histopathology

Objectives Since differential diagnosis in ultrasound (US) imaging of myometrial lesions can be challenging particularly in the highly vascularized ones, we aimed to correlate the ultrasound appearance of highly vascularized uterine myomas with the histopathological diagnosis. Methods We recruited patients with a preoperative US-diagnosis of highly vascularized uterine myoma characterized by circumferential and intralesional vascular pattern (color score assessment of 3 or 4, according to the Morphological Uterus Sonographic Assessment), who underwent myomectomy or hysterectomy. Additional US-characteristics including cystic area, echogenicity, borders, shadowing, and size were recorded for each patient at baseline. US features were matched with histological characteristics, namely the mitotic count and the presence of cellular atypia and/or coagulative necrosis, for each patient. Results 70 patients with highly vascularized uterine myomas were included; mean (± S.D.) age 46.5 years (46.5 ± 11.4), and 13 (18.5%) were post menopause. At histological examination, 93% of cases were benign lesions (32 myomas were typical leiomyoma, 29 were variants of leiomyoma, and 4 were adenomyomas). Whereas 7% were malignant masses (2 uterine sarcomas, 1 leiomyosarcoma, 1 neuroendocrine tumor, 1 uterine smooth muscle tumors of uncertain malignant potential: STUMP). Ultrasound demonstrated cystic areas within the lesion in 10/32 typical leiomyoma, in 16/29 variants of leiomyoma, in all adenomyomas, and in the STUMP and the leiomyosarcoma patients. Borders were regular in 64/65 benign lesions, and 2/5 malignant lesions (p<0.05). No significant differences in terms of echostructure, shadowing and size were found between the two groups. Endometrium was visible in 55/65 benign lesions and 2/5 malignant lesions (p=0.458). The age of patients with malignant lesions was higher than those with benign lesions (64.8±16.0 vs 42.4±5.1; p<0.001) and all were over 45 years. Conclusion Despite the low number of high vascularized myomas observed, our results showed that ultrasound features of myomas, such as circumferential and intralesional vascularity, cystic areas, and dimensions are important parameters, especially when combined with the patient's age. Such features could be useful to differentiate typical myomas from benign variants and malignant lesions in a pre-operative setting and to select patients that may benefit from a conservative management rather than surgery. This article is protected by copyright. All rights reserved.