Primary appendiceal malignancy mimicking advanced stage ovarian cancer.

Primary appendiceal malignancies are rare and account for less than 0.5% of all gastrointestinal tumors [1]. While these tumors are not very common, they have a tendency for ovarian spread when they disseminate beyond the appendix. Most of them are presented at the emergency room with nonspecific symptoms, such as acute abdominal pain and huge pelvic mass, mimicking advanced stage ovarian cancer. Definite diagnosis preoperatively or intraoperatively is not easy. Therefore, gynecologists, as well as surgeons, radiologists and gastroenterologists, should consider carcinoma of the appendix in the differential diagnosis of ovarian cancer. In addition, at the time of laparotomy, the appendix should be evaluated carefully for suspected ovarian carcinoma. A 50-year-old woman presented at the emergency room with complaints of lower abdominal pain. Clinical examination revealed a protuberant, tense and diffusely tender abdomen. A tender mass in the right adnexal region was noted on pelvic examination. An ultrasound scan demonstrated a solid/cystic mass of 16 cm in diameter in the right ovarian region, while the uterus and left ovary were found normal in size and morphology. Computed tomography (CT) scan confirmed the presence of a 16 cm right pelvic mass with thin-walled septum, but no lymph nodes were revealed. There was no mention of the appendix. The mass was suspected to be a cystadenocarcinoma of the ovary (Figure 1). Serum CA-125 levels showed a value of 73.8 U/mL. The other hematologic and biochemical tests were normal, and the chest X-ray result was negative. Three days later, the patient underwent laparotomy. During surgery, a complex cystic ovarian mass (15 cm) with a gelatinous discharge extruding through the capsule of the right mass was found (Figure 2). Peritoneal carcinomatosis was extensive. Pseudomyxoma peritonei due to mucinous cystadenoma or cystadenocarcinoma of the ovary were considered to be the primary process first. However, swollen appendix with intraluminal glassy mucinous masses and gelatinous discharge extruding through the serosa were also found during the operation. Under the impression of ovarian cancer with extensive metastasis, optimal debulking surgery was performed smoothly. Pathologic examination reported that sections of the appendix and right ovary show mucinous cystadenocarcinoma, lined by mucin-producing cells with stromal invasion. The tumor cells of both sites, including right ovary and appendix, were positive for CK20 and negative for CK7, which were consistent with mucinous cystadenocarcinoma of appendiceal origin. The histologic features of peritoneal pseudomyxoma were also examined (Figure 3). PRIMARY APPENDICEAL MALIGNANCY MIMICKING ADVANCED STAGE OVARIAN CANCER