Mucinous Cystadenoma

A 53-year-old perimenopausal woman presented to the emergency department with throbbing lower abdominal pain and distention. The pain started 5 days earlier and worsened with sitting and walking; she also experienced increasing dyspnea. She had noticed increasing abdominal girth about 5 months earlier. Since then, she had gained 5 to 10 lb, despite dieting. The patient reported a 22-pack-year history of smoking but no alcohol use. She was taking over-the-counter painkillers and allergy medications. Her family history was notable for a brother who died of laryngeal cancer.

The patient was 4 ft 9 in tall and weighed 115 lb (normal weight, 105 lb). Blood pressure was 148/ 72 mm Hg; other vital signs were normal. The abdomen was soft, distended, and tender without rebound or guarding; bowel sounds were normal. A palpable mass extended from thesymphysis pubis to near the umbilicus.

Results of a complete blood cell count, basic metabolic panel, urinalysis, amylase and lipase tests, and liver function tests were normal. A human chorionic gonadotropin urine test was negative. Abdominal and pelvic CT scans showed a large multiloculated cystic mass that arose from the pelvis and extended to the level of the diaphragm (A). There were multiple fibroids in the uterus and no peritoneal free fluid.

The cancer antigen 125 test (CA-125) value was 16 U/mL (normal range, less than 35 U/mL). Exploratory laparotomy revealed a large solid, cystic mass arising from the right ovary. A total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed. The excised mass was 24 × 15 × 14 cm and weighed about 8 lb (B); it was smooth without excrescences and was composed of gelatinous cysts. Pathological results revealed benign mucinous cystadenoma.

The patient tolerated the surgery well and recovered without complications. After the operation, she returned to her normal level of activity.

Mucinous cystadenomas are relatively common (12% to 15% of all ovarian tumors).¹ They can become massive. These tumors usually develop in the third to fifth decades of life and typically cause vague symptoms, such as increasing abdominal girth, abdominal or pelvic pain, emesis, fatigue, indigestion, constipation, and urinary incontinence.^2,3 Because this patient's 8-lb tumor was disproportionately large for her small frame, it restricted the motion of her diaphragm and led to dyspnea.

Although mucinous cystadenomas are benign, they can progress to cystadenocarcinomas; they may also contain pockets of malignancy that are easily missed.⁴ Smoking is a known risk factor for mucinous ovarian cancer.⁵

Because the clinical picture of benign and malignant mucinous tumors is very similar, biopsy is the preferred method of diagnosis. Laparoscopy with characteristic ultrasonographic findings at a minimum is required; however, open laparotomy may be necessary for staging and treatment.⁶ Measurement of CA-125 is often not helpful for diagnosis, because an elevated level is an inconsistent finding in ovarian malignancies.

Diagnosis is often delayed because women frequently fail to report symptoms or attribute them to other causes (eg, menopause). This patient thought she was "getting fat" and ignored her symptoms until the tumor had grown significantly. Fortunately, malignancy did not develop during the 5-month gap between the first symptoms and diagnosis.