Leiomyosarcoma leptomeningeal brain metastases.

Brain metastases from soft tissue sarcomas (STS) occur late and relatively rarely, most commonly after lung metastases have developed. Furthermore, they are most commonly intraparenchymal in distribution. We describe two cases of histologically confirmed intracranial metastatic soft tissue leiomyosarcomas. In both cases all the nodular metastases measuring 10 mm in diameter or less could be easily detected in the leptomeningeal spaces by MRI. However, as the lesion enlarges it is difficult to recognize the site of origin, and the mass appears and behaves as intra-axial. Lesions located in the leptomeningeal spaces and in the perivascular space can be extremely small, which makes their detection problematic. For this reason we believe that in this context, MRI global gadolinium enhanced imaging using contiguous 1 mm slice thickness acquisition (TR 23 ms,TE 8 ms 512×512 matrix) is preferable, since the patient's management may vary depending on the multiplicity and location of the lesions.