Stromal sarcoma (Endolymphatic stromal myosis)

Endometrial stroma in myometrium can be benign or malignant. Benign stromal nodules of endometrial stroma in myometrium do not invade surrounding tissue or blood vessels. Endometrial stromal sarcoma, a malignancy, invades myometrium. When it invades lymphatic channels, as in this case, it is called endolymphatic stromal myosis by some who regard it as an intermediate malignancy with fewer mitoses than endometrial stromal sarcoma.

Endolymphatic stromal myosis is regarded as less malignant than the usual endometrial stromal sarcoma but a substantial proportion of patients (50% in one study) will develop recurrences after the initial surgery. Lung metastases can occur (see the pulmonary section of this website). Fortunately, some tumors have positive estrogen and progesterone receptors and are responsive to hormonal therapy.