Uterine blush mimicking a hypervascular tumour in the pelvis as demonstrated by a triple-phase bone scan

Transient visualization of the uterus, mimicking a hypervascular soft tissue tumour in the pelvic region, in the blood flow and blood pool phases of a triple-phase bone scan, was seen in 78 of 91 females of reproductive age. It was noted in all cases of menstrual (n = 15), early proliferative (n = 9) and secretory (n = 42) phases of the cycle, but in only 12 of 25 subjects studied in the late proliferative phase. This observation differs from previous reports of uterine uptake only being seen in the menstrual and secretory phases, or in all menstrual cycle phases. None of the 58 control patients (20 males, 16 pre-menarcheal females and 22 post-menopausal females) had such uterine uptake in either the blood flow or blood pool phase in the pelvic region. We suggest that this normal physiological phenomenon, mimicking a hypervascular soft tissue tumour in the pelvis, occurs in the menstrual, early proliferative and secretory phases of pre-menopausal females and in all phases of the cycle in younger females of reproductive age.