Benign metastasising leiomyoma (BML) is a rare metastatic phenomenon that is observed when a pelvic leiomyoma is present.
Women who have undergone hysterectomy for leiomyomas are most commonly affected.
Patients are usually asymptomatic at presentation. A history of a hysterectomy for uterine leiomyoma may be indicative. Occasioanlly symptoms of chest pain, shortness of breath, and cough may be present.
The condition is characterized by multiple well-differentiated leiomyomas at sites distant from the uterus. The lesions are histologically identical to their uterine counterparts. It is generally considered that the lesions are a result of haematogenous metastases from benign tumours although some support the hypothesis of multiple independent foci of smooth muscle proliferation.
Although most commonly seen in the lungs 2, other sites of involvement include lymph nodes, peritoneum, and retroperitoneal structures.
Imaging features are often non-specific 3.
When there is lung involvement this may be seen as multiple nodules and pulmonary masses on chest radiography and/or CT. Mediastinal and hilar lymphadenopathy is rare. Cavitation of lesions may occasionally take place and rarely may be accompanied by a pneumothorax. Calcification is rare. Following intravenous contrast, the lesions usually enhance homogeneously 3. Occasional cases have been reported with a miliary pattern or a pattern simulating interstitial lung disease.
Treatment and prognosis
The clinical course is typically indolent and spontaneous resolution has been described.
History and etymology
The condition was first described by P E Steiner in 1939 4.
For lung nodules there can be a wide differential which includes:
- 1. Abramson S, Gilkeson RC, Goldstein JD et-al. Benign metastasizing leiomyoma: clinical, imaging, and pathologic correlation. AJR Am J Roentgenol. 2001;176 (6): 1409-13. AJR Am J Roentgenol (full text) - Pubmed citation
- 2. Chan CY. A woman with a pelvic mass and pulmonary nodules. Br J Radiol. 2004;77 (917): 459-60. doi:10.1259/bjr/22684696 - Pubmed citation
- 3. Fasih N, Prasad shanbhogue AK, Macdonald DB et-al. Leiomyomas beyond the uterus: unusual locations, rare manifestations. Radiographics. 28 (7): 1931-48. doi:10.1148/rg.287085095 - Pubmed citation
- 4. Steiner PE. Metastasizing fibroleiomyoma of the uterus: Report of a case and review of the literature. Am. J. Pathol. 1939;15 (1): 89-110.7. - Free text at pubmed - Pubmed citation