VATS biopsy of a left lower lung nodule showed:

"Sections of the tumor mass show it to consist of bundles of smooth muscle fibers surrounded by a fibrous tissue stroma. Amongst the smooth muscle and fibrous tissue, there are a number of entrapped glandular structures lined by cuboidal to columnar epithelium. These are more prominent at the periphery of the lesion. The tumor cells show positive staining with smooth muscle actin, desmin and also with estrogen and progesterone receptors. The entrapped glandular tissue shows positive staining with TTF-1. The features, including positive staining with hormone receptors, are typical of benign metastasizing leiomyoma."

This case is just an example of an interesting pathology - there are no specific imaging features that would suggest metastasizing leiomyoma.