Favorable response to antigonadal therapy for a benign metastasizing leiomyoma

Abstract

Background: Benign metastasizing leiomyoma and lymphangioleiomyomatosis (LAM) both are characterized by abnormal proliferation of smooth muscle-like cells in the lung.

Case: A 32-year-old African woman with a diagnosis of LAM underwent myomectomy for uterine leiomyomas. An alternative diagnosis of benign metastasizing leiomyoma was made on repeat lung biopsy. Treatment with leuprolide acetate decreased pulmonary infiltrates and improved lung function and exercise tolerance.

Conclusion: Accurately diagnosing benign metastasizing leiomyoma has important implications for clinical outcome. Because its clinical presentation may be misleading, immunohistochemical techniques may assist in differentiating benign metastasizing leiomyoma from LAM. This is important because, in benign metastasizing leiomyoma, reduced tumor burden and improved pulmonary function may be achieved by suppressing gonadal steroids.

Figure 1

Computed tomography images of the lung before initiating anti-gonadal therapy (panel A) and 24 months after treatment with leuprolide acetate (panel B). Panel B shows a significant decrease in the density of the interstitial pulmonary infiltrates following anti-gonadal therapy. Panel C shows changes in lung function expressed as percent predicted of the normal total lung capacity, forced vital capacity, forced expiratory volume in the first second (, and diffusion capacity for carbon monoxide, during 11 years of follow-up. After initiation of leuprolide acetate therapy (arrow), total lung capacity increased 10% (500 mL), forced vital capacity increased 15% (300 mL), forced expiratory volume in the first second increased 14% (270 mL), and diffusion capacity for carbon monoxide increased 4%.

Figure 1

Computed tomography images of the lung before initiating anti-gonadal therapy (panel A) and 24 months after treatment with leuprolide acetate (panel B). Panel B shows a significant decrease in the density of the interstitial pulmonary infiltrates following anti-gonadal therapy. Panel C shows changes in lung function expressed as percent predicted of the normal total lung capacity, forced vital capacity, forced expiratory volume in the first second (, and diffusion capacity for carbon monoxide, during 11 years of follow-up. After initiation of leuprolide acetate therapy (arrow), total lung capacity increased 10% (500 mL), forced vital capacity increased 15% (300 mL), forced expiratory volume in the first second increased 14% (270 mL), and diffusion capacity for carbon monoxide increased 4%.

Figure 1

Computed tomography images of the lung before initiating anti-gonadal therapy (panel A) and 24 months after treatment with leuprolide acetate (panel B). Panel B shows a significant decrease in the density of the interstitial pulmonary infiltrates following anti-gonadal therapy. Panel C shows changes in lung function expressed as percent predicted of the normal total lung capacity, forced vital capacity, forced expiratory volume in the first second (, and diffusion capacity for carbon monoxide, during 11 years of follow-up. After initiation of leuprolide acetate therapy (arrow), total lung capacity increased 10% (500 mL), forced vital capacity increased 15% (300 mL), forced expiratory volume in the first second increased 14% (270 mL), and diffusion capacity for carbon monoxide increased 4%.

Figure 2

Histologic sections of initial lung biopsy. Panel A shows a distinctive pattern of cystic lesions, along with multinodular proliferation of smooth muscle cells characteristic of lymphangioleiomyomatosis (hematoxylin-eosin staining; magnification × 50, bar-graph 250 micrometers). Panel B: high magnification view of one nodule showing characteristic smooth muscle cells (hematoxylin-eosin staining; magnification × 200, bar-graph 100 micrometers).