Consequences of a wait-and-see strategy for benign metastasizing leiomyomatosis of the lung.

Pulmonary benign metastasizing leiomyomatosis (BML) is a rare smooth-muscle cell disorder of the lung. Most BML lesions stay constant in size for a long time. The prevailing treatment option is primary excision of the nodules or if unresectable, long-time hormone therapy. Herein, we present a case of BML in which a wait-and-see strategy after diagnosis was decided. Fourteen years later a routine chest roentgenogram revealed multiple bi-lobar BML lesions with a giant cyst filling the whole left lung cavity. We conclude that a wait-and-see procedure for BML is feasible, but primary resection of the BML tumor masses is preferable to avoid complications as described in our case.