A 47-year-old woman presented to the hospital with a 1-month history of abdominal distention.
Physical examination revealed a huge mass in the lower abdomen.
The peripheral blood test showed elevated levels of carcinoembryonic antigen (CEA, 335.2 ng/mL [normal, <5 ng/mL]) and carbohydrate antigen (CA) 125 (219 U/mL [normal, <45 U/mL]) but a normal level of CA19-9 (9 U/mL [normal, <37 U/mL]).
Computed tomography (CT) demonstrated a large, round mass with a maximum diameter of 15 cm in the pelvic cavity without the presence of ascites or pleural effusion (Fig.1a, ​b).
Colonoscopy identified an elevated lesion with severe stenosis in the sigmoid colon, and histopathological examination of biopsy specimens from the tumor showed moderately differentiated adenocarcinoma.
Although we scheduled an early operation, the patient developed acute dyspnea and general edema 2 weeks after the first CT scan.
The second CT scan examination demonstrated massive bilateral pleural effusion with atelectasis and ascites (Fig.2a, b).
Thoracic drainage and laparotomy were emergently performed.
Macroscopically, the tumor in the sigmoid colon had invaded the serosa, and the huge pelvic mass was found to contain a right ovarian tumor.
Several small nodules of peritoneal dissemination were distributed over the greater omentum.
Perioperatively, 3800 mL of serous ascitic fluid was drained.
Cytodiagnosis of the fluid drained from the ascites and pleural effusion revealed no tumor cells.
Bilateral oophorectomy, total hysterectomy, omentectomy, and sigmoidectomy with regional node dissection were performed (Fig.3a).
Histopathological examination of the resected specimens showed moderately differentiated adenocarcinoma in the tumors of both the ovaries and the sigmoid colon (Fig.3b).
The dissected paracolic nodes showed malignant cells.
Immunohistochemically, tumor cells from the ovaries and the colon both showed positive expression of cytokeratin 20 (CK20) but no expression of cytokeratin 7 (CK7), confirming that the ovarian tumors were metastases from primary colon cancer (Fig.4a, ​b).
The postoperative course was uneventful, and both pleural effusion and ascites rapidly resolved.
Postoperatively, a regimen of 5-fluorouracil (5-FU), leucovorin, and oxaliplatin (FOLFOX) was administered every 2 weeks for 5 months.
At 29 months after the first operation, the patient required curative hepatic resection for liver metastases.
At 78 months after the first operation, the patient remains alive with no evidence of a disease.