Massive ovarian edema is a rare entity that can be confused with an ovarian neoplasm. A few ovarian lesions have been reported that are associated with massive ovarian edema. This article describes the first case of an ovarian serous cystadenoma associated with a massive ovarian edema. The patient was a 17-year-old female who was referred to the emergency room because of lower abdominal pain. Subsequent ultrasound and computed tomography scanning studies revealed an abdominopelvic cystic mass suggestive of an ovarian neoplasm. She underwent an exploratory laparoscopy, and a left salpingo-oophorectomy was performed. The specimen weighed 1610 g and consisted of a cystic mass measuring 17 x 15 x 8 cm attached to a solid mass measuring 13 x 11 x 4 cm. Microscopy revealed a cystic and a solid lesion. The cystic structure was composed of a flat or cuboidal single-layer lining showing ciliated epithelium and focal areas of papillary structures compatible with a diagnosis of ovarian serous cystadenoma. The solid mass had an intact capsule and diffuse interstitial edema, preserving the overall structure of the ovary and sparing the outer cortex. These findings are compatible with the diagnosis of ovarian massive edema. This report of an association of serous cystadenoma with massive ovarian edema broadens the histologic spectrum in which a massive ovarian edema may be encountered.