A Rare Triple Coexistence Of A Collision Tumor, A Benign Mature Cystic Teratoma And A Hemorrhagic Follicular Cyst Of The Ovaries

摘要

Ovarian collision tumors are rare entities and most commonly consist of a benign mature ovarian teratoma and an ovarian cystadenoma or cystadenocarcinoma. Serous cystadenomas are the most common ovarian neoplasms, representing 20% of them. Benign mature ovarian cystic teratomas are often diagnosed in women of child-bearing age (12-15% of ovarian neoplasms). Benign mature ovarian solid teratomas are less common than the cystic ones. Follicular cysts are cysts of unruptured mature ovarian follicles. We present a rare case of a triple coexistence of a large collision tumor (consisting of a serous cystadenoma and a benign mature cystic teratoma) in the right ovary and a benign mature solid teratoma and a hemorrhagic follicular cyst in the left ovary of a young-aged woman, with a palpable mass in the lower abdomen. Right-sided salpingo-oophorectomy and left ovarian cystectomy preserving as much intact ovarian tissue as possible, took place.The possible existence of an ovarian collision tumour should carefully be examined pre- and postoperatively and histologically, so as to avoid misdiagnosis of a possible malignancy. Introduction Collision tumors represent a coexistence of two adjacent but histologically distinct tumors, without histologic admixture in an organ [1]. Collision tumors have been reported in various organs, but they are rare in ovaries. Ovarian collision tumors are most commonly composed of teratoma and cystedenoma or cystadenocarcinoma, but other histologic combinations have been also reported [2, 3], with the mechanism of origin still uncertain.Ovarian serous cystadenomas represent 20% of all ovarian tumors. They usually appear during the climacteric age as unilocular cysts, with a diameter less than 15 cm and containing serum-like fluid [4].Ovarian teratomas are the most common germ cell neoplasms and, in many series, the most common excised ovarian neoplasms [5]. The most common of these tumors are the benign mature cystic teratomas (also known as dermoid cysts), representing 12-15% of the ovarian neoplasias [4]. Mature cystic teratomas are bilateral in about 10% of cases [6].The mature solid teratomas are another type of ovarian teratomas, which do not meet the criteria for an immature teratoma. They are benign teratomas, just like the cystic ones [7].The follicular cysts are solitary or multiple cysts of unruptured ovarian follicles, which appear in the ovarian surface as pale cystic masses, with a diameter rarely exceeding 4 cm [4]. We present a rare case of a non child-bearing young-aged woman, who was hospitalized for the removal of a large cystic mass, probably arising from the right ovary. The eventual pathology exam revealed a collision tumor of a benign serous cystadenoma and a mature solid teratoma in the right ovary, and a mature cystic teratoma and a hemorrhagic follicular cyst in the left ovary. Case Report A 29-year-old non child-bearing female, presented to our department complaining of a palpable mass in the lower abdomen, with a chronic mild pelvic pain and menstrual irregularity. The patient denied fever or chills and, except for pain, had no significant gastrointestinal symptoms. The patient, on admission, had a menstrual period, the onset of which was delayed for two weeks. She had no significant medical or surgical history. Family history was negative.Abdominal examination revealed a large, smooth, palpable and mobile mass, extending from the pelvis to approximately 3-4 cm below the umbilicus. The lower border of this mass was palpable through a vaginal digit exam. There was no guarding or rebound tenderness. Abdominal ultrasound revealed a unilocular cystic mass of 17 cm in diameter, probably originating from the right ovary, with a thin cystic wall and without hyper-echogenic content. There was no free fluid detected between the intestinal loops or in the Douglas pouch (Fig.1).