[Benign metastasizing leiomyoma of the lung--a rare differential diagnosis of pulmonary space-occupying lesions].

HISTORY AND ADMISSION FINDINGS

A 45-year-old woman was refferred for diagnosis of an accidentally found symptomless space-occupying lesions in the central part of the right lung. She had undergone a hysterectomy 4 years before and reported smoking 15 cigarettes daily since the age of 17 years. Physical examination was normal.

INVESTIGATIONS

As primary bronchial carcinoma or metastasis to the lung was suspected she underwent a series of diagnostic tests: sonography, computed tomography (CT), gastroscopy, coloscopy, bronchoscopy, skeletal scintigraphy, gynaecological examination and various laboratory tests, none of which indicated a primary extrapulmonary tumour. CT-guided fine-needle biopsy then suggested benign metastasizing pulmonary leiomyoma (BMPL).

TREATMENT AND COURSE

The largest of the tumours were surgically removed, confirming BMPL. Hormone receptors (for oestrogen, progesterone) having been demonstrated, progesterone treatment was initiated as prophylaxis against recurrences. CT 6 months later revealed new intrapulmonary foci. Administration of luteinizing hormone-releasing hormone analog to stop completely any oestrogen effect, and CT of the thorax 6 months later showed that both tumour numbers and their size had been reduced. The patient remained asymptomatic and the findings had not changed in the subsequent 12 months.

CONCLUSION

BMPL is a rare cause of a space-occupying pulmonary lesion, predominantly affecting middle-aged women after hysterectomy for uterine myoma. The pathogenesis remains unclear, hormone-dependent tumour growth being discussed as a possible mechanism. Anti-oestrogen administration is the treatment of choice to achieve remission and effective prevention of recurrences.