The clinical histories of 10 women suffering from benign metastasizing
leiomyoma (BML) after
hysterectomy and information on lung lesions detected in these women are presented, together with corresponding data for 2 women with metastasizing
leiomyosarcoma of the uterus for comparison: gross appearance, survival, and light microscopical, immunohistochemical and
lectin-histochemical findings are reported. All patients with BML had undergone
hysterectomy for uterus leiomyomatosus without any detection of sarcomatous lesions in the uterus wall. After a median period of 14.9 years intrapulmonary masses were detected by imaging techniques. On average, six nodules with a mean 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
indicator of the presence of lymphokine
macrophage migration inhibitory factor,
antibodies and the labeled
protein to assess
galectin (galactoside-binding
animal lectin)-dependent parameters, analysis of
tumor vascularization (CD-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 vascularization compared with
metastases from the two uterine
sarcomas, remarkable p53 overexpression and frequent expression of the lymphokine, the
galectins and accessible binding sites. The median survival of the BML patients was 94 months after excision of the intrapulmonary lesions, and the maximum survival of the two
sarcoma patients was 22 months. The results recorded in this patient sample with the methodology applied suggest that benign metastasizing
leiomyomas are a slow-growing variant of
leiomyosarcoma of the uterus, which becomes clinically apparent at a young age and progresses with low velocity.