Malignant mixed Müllerian tumors of the uterus: sonographic spectrum

To describe the sonographic findings for malignant mixed Müllerian tumors (MMMTs) of the uterus with particular emphasis on their features on saline contrast sonohysterography (SCSH) and color Doppler sonography, and to determine how they relate to pathological findings.

The SCSH and color Doppler findings in 29 histologically proven cases of uterine MMMT were reviewed retrospectively and their relationship to gross and histological findings were investigated.

Of the 29 uterine tumors, 16 were located only in the corpus, nine only in the fundus and four in both the corpus and fundus. Mean tumor size was 5.4 cm. The most common appearance was a polypoid mass projecting into the endometrial cavity, found in 23 cases. Twenty-eight tumors had an irregular surface, which was papillary in 20 cases and lobulated in eight. Most appeared heterogeneously isoechoic (n = 16) or hypoechoic (n = 12), occasionally with a trabecular appearance, and they often had clefts or fissure-like cystic areas (n = 10), necrosis (n = 4) or hemorrhagic areas (n = 7). Myometrial invasion was present in 27 cases and dilatation of the endometrial cavity was seen in 11. Color Doppler sonography showed moderate to marked vascularity in 20 out of the 24 cases in which it was performed, with a mean resistance index of 0.41, and appeared as feeding (n = 15) or randomly dispersed (n = 9) vessels.

Uterine MMMTs have distinct sonographic features that are related to pathological findings. Knowledge of the sonographic appearance of MMMTs may facilitate diagnosis.