图示：子宫平滑肌瘤红色变性
此种外观使我们认为可能是恶性肿瘤，然而子宫平滑肌瘤很少恶变，由此看来事情并不坏，因为子宫平滑肌瘤太常见了(20%妇女有可能发生)。绝经期后，子宫平滑肌瘤开始变小并纤维化。
子宫平滑肌瘤：宫底粘膜下(大体) | 多发性 | 示红色变性（大体） | MRI盆腔矢状面 | 高分化
Here is a very large leiomyoma of the uterus that has undergone degenerative change and is red (so-called "red degeneration"). Such an appearance might make you think that it could be malignant. Remember that malignant tumors do not generally arise from benign tumors, which is a good thing, because leiomyomas are so common (20% of women will have at least one). Postmenopausally, leiomyomas tend to regress in size and become fibrotic.