benign metastasizing leiomyoma
Benign metastasizing leiomyomas (or leiomyomata) are a rare non-malignant metastatic phenomenon that may be observed with a pelvic leiomyoma.
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. Occasionally 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 tumors although some support the hypothesis of multiple independent foci of smooth muscle proliferation.
Although most commonly seen in the lungs , other sites of involvement include lymph nodes, peritoneum, and retroperitoneal structures.
Imaging features are often non-specific .
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 . 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 .
For lung nodules, there can be a wide differential which includes:
- lung metastases from a malignant tumor
- infectious pulmonary granulomata
- pulmonary sarcoidosis (nodular)
- rheumatoid nodules
- pulmonary amyloidosis