Endolymphatic stromal myosis: a case with positive estrogen and progesterone receptors and good response to progestins.

This report describes a case of recurrent and metastatic endolymphatic stromal myosis (ESM), which showed good response to progestin therapy. Metastatic lung nodules regressed after medroxyprogesterone acetate (MPA) treatment, recurred while MPA was stopped, and disappeared again when MPA was restarted. The levels of estrogen and progesterone receptors measured in the resected tumor amounted to 79.5 and 310 fmole/mg protein, respectively. Sex steroid hormone dependency of ESM was reviewed in the literature.