If no fetal tissue or villi are observed grossly, ectopic pregnancy must be excluded by ultrasound. 如果肉眼检查没有见到胎儿组织或绒毛，需要用超声波排除异位妊娠。
This is because some lung cancer cells can secrete a human chorionic gonadotropin, the hormone can cause breast tissue, breast mast. 这是因为某些肺癌细胞能分泌出绒毛膜促性腺激素，这种激素可引起乳腺组织增生，使乳房肥大。
