Benign metastasizing leiomyoma of the uterus: documentation of clinical, immunohistochemical and lectin-histochemical data of ten cases

The clinical histories of 10 women suffering from benign metastasizing leio myoma (BML) after hysterectomy and information on lung lesions detected in these women are presented, together with corresponding data for 2 women wit h metastasizing leiomyosarcoma of the uterus for comparison: gross appearan ce, survival, and light microscopical, immunohistochemical and lectin-histo chemical findings are reported. All patients with BML had undergone hystere ctomy for uterus leiomyomatosus without any detection of sarcomatous lesion s in the uterus wall. After a median period of 14.9 years intrapulmonary ma sses were detected by imaging techniques. On average, six nodules with a me an diameter of 1.8 cm were seen. Resection of the lesions was performed in all cases. The immunohistochemical and lectin-histochemical examination of the tumors included analysis of the proliferation-associated protein Ki-67, the p53 protein, estrogen and progesterone receptor, sarcolectin as an ind icator of the presence of lymphokine macrophage migration inhibitory factor , antibodies and the labeled protein to assess galectin (galactoside-bindin g animal lectin)-dependent parameters, analysis of tumor vascularization (C D-34), and expression of bcl-2, vimentin, smooth muscle actin, desmin, and keratin. The lesions were characterized by low proliferation activity of 2. 9% (measured with Ki-67), frequent hormone receptor expression (8 of the 10 cases presented hormone-specific receptors), low to moderate vascularizati on compared with metastases from the two uterine sarcomas, remarkable p53 o verexpression and frequent expression of the lymphokine, the galectins and accessible binding sites. The median survival of the BML patients was 94 mo nths after excision of the intrapulmonary lesions, and the maximum survival of the two sarcoma patients was 22 months. The results recorded in this pa tient sample with the methodology applied suggest that benign metastasizing leiomyomas are a slow-growing variant of leiomyosarcoma of the uterus, whi ch becomes clinically apparent at a young age and progresses with low veloc ity.