renatal sonographic diagnoses of subcutaneous soft tissue masses include hemangiomas, malformations (capillary, lymphatic, venous, arterial, or mixed), teratomas, and, rarely, sarcomas. 1-5 Prenatally depicted malformations may be seen in association with more complex fetal conditions, including Klippel-Trenaunay-Weber (angio-osteohypertrophy) and Proteus syndromes. [6][7][8][9] We present an unusual case in which extensive multiple soft tissue tumors encompassing the fetal upper chest, back, nuchal area, and bilateral axillae, considered consistent with multiple large lymphatic malformations noted at 23 weeks' gestation, decreased in size throughout the remainder of gestation. At delivery, relatively small subcutaneous masses remained. Tissue histopathologic findings obtained at biopsy and the neonate's clinical course during which the subcutaneous masses underwent a marked spontaneous decrease in size, were consistent with low-flow mixed lymphatic and venous malformations.A 29-year-old patient, gravida 3, para 2, was followed during her third pregnancy at the State University of New York Downstate Medical Center. Her medical and obstetric histories were unremarkable, and her current pregnancy was uneventful. Results of second-trimester serum screening for aneuploidy was negative.Sonography at 23 weeks' gestation depicted a singleton vertex-presenting female fetus with normal-appearing fetal anatomy other than extensive multiple semicystic, semisolid subcutaneous masses located on the entire upper anterior chest wall, both axillae, back, and nuchal areas (Figures 1-3). Minimal vascularity was depicted on color Doppler imaging. The estimated fetal weight was 700 g (80th percentile for gestational age).