Pseudomyxoma peritonei, first described by Werth in 1884,¹ is an uncommon tumor in which the peritoneum and omentum are filled with large quantities of yellowish-greenish gelatinous mucus and mucinous cysts. Rupture of a primary cyst-adenoma or adenocarcinoma, usually of the appendix or ovary, is the most common cause. The diagnosis is usually made by laparoscopy or laparotomy, and x-rays, including CT scan, are not usually helpful in making a definitive diagnosis. The course of these patients is that of progressive abdominal accumulation of mucinous material, usually leading to repeated surgical evacuations and death from intestinal obstruction and its sequelae.² Definitive treatment has not been established. This report describes two cases of pseudomyxoma peritonei diagnosed by laparoscopy at the Gastroenterology Unit, Riyadh Armed Forces Hospital.

Case

The first patient, a 30-year-old Saudi female, was admitted to the hospital on 18 January 1986 with a 6-month history of abdominal distention and fever. Clinical examination revealed the presence of ascites. The second patient, a 41-year-old Saudi male, was admitted on 30 April 1986 and had a 1-year history of abdominal pain and abdominal swelling. Examination showed tense ascites and umbilical hernia.

In both cases the provisional diagnosis was intestinal tuberculosis. In both, results of hematologic and biochemical blood tests were normal. Serologic blood tests (hepatitis B screen hydatid and schistosomal titers) were also normal. Paracentesis in both showed a yellow ascitic fluid the laboratory tests of which were not specific. Abdominal x-ray examination, including plain ultrasound, and CT scan, revealed the presence of ascites and failed to provide a diagnosis.

Laparoscopy was performed in both under local anesthesia. In the first patient, this showed straw-colored ascitic fluid and multiple small cystic masses. The differential diagnosis included disseminated hydatid disease. The biopsy was not conclusive, and it was decided to proceed to laparotomy. Laparotomy confirmed the laparoscopic findings and, in addition, revealed an enlarged appendix and cystic changes in the left ovary. Appendectomy, left oophorectomy, and partial resection of the large omentum were done. Histologic examination showed disseminated low-grade mucinous cystadenoma.

In the second case, the laparoscopic findings showed thick ascitic fluid, multiple small gelatinous cysts, and jelly-like nodules fixed on the surface of the peritoneum (Figure 1). A diagnosis of pseudomyxoma peritonei was made, which was confirmed histologically (Figure 2).

Both patients were seen by the oncologist who thought that chemotherapy or radiotherapy would probably not be helpful.

Discussion

Pseudomyxoma peritonei is an uncommon tumor, the diagnosis of which may be difficult to make clinically or radiologically. There is a considerable controversy over the precise cause and pathogenesis of pseudomyxoma peritonei, but it is perhaps best described as a form of peritoneal carcinomatosis with a variable prognosis.³

The clinical presentation in this condition may mimic intestinal tuberculosis, especially in areas where tuberculosis is common, and the findings of cystic lesions during laparoscopy may simulate hydatid daughter cysts.

Conventional radiographic studies are not diagnostic. In our patients, radiographic studies were not helpful, including CT scan. There are some reports indicating that CT scan might be helpful in diagnosing pseudomyxoma peritonei.^4,5

Laparoscopy is helpful in diagnosing pseudomyxoma peritonei⁶ while laparotomy will reveal the extent of the disease, as well as allow surgical removal. Herrerias et al⁷ studied five cases of pseudomyxoma peritonei, in whom laparoscopic findings were diagnostic. Another five cases, diagnosed by peritoneoscopy, were reported by Sato et al,⁸ who concluded that peritoneoscopy is one of the more helpful procedures for the early diagnosis of pseudomyxoma peritonei and is particularly useful in the follow-up assessment of the effectiveness of chemotherapy.

References

1. Werth R, cited by Balthazar EJ, Javors BR. Pseudomyxoma peritonei, clinical and radiographic features. Am J Gastroenterol 1977;68(5):501-9.

2. Fernandez RN, Daly JM. Pseudomyxoma peritonei. Arch Surg 1980;115(4):409-14.

3. Sandenbergh HA, Woodruff JD. Histogenesis of pseudomyxoma peritonei: a review of 9 cases. Obstet Gynecol 1977;49(3):339-45.

4. Gustafson KD, Karnaze GC, Hattery RR, Scheithauer BW. Pseudomyxoma peritonei associated with mucinous adenocarcinoma of the pancreas: CT findings and CT-guided biopsy. J Comput Assist Tomogr 1984;8(2):335-8.

5. Weigert F, Lindner P, Rohde U. Computed tomography and magnetic resonance of pseudomyxoma peritonei. J Comput Assist Tomogr 1985;9(6):1120-2.

6. Chui CJ. Pseudomyxoma peritonei diagnosed by peritoneoscopy. Aust NZ J Surg 1975;45(3):277-9.

7. Herrerias JM, Muniain M, Pellicer F, et al. The spectrum of pseudomyxoma peritonei: a study of 5 cases. Rev Esp Enferm Apar Dig 1985;68(3):255-7.

8. Sato W, Komatsu K, Morial N, et al. Five cases of pseudomyxoma peritonei with reference to the peritoneoscopic findings. Gastroenterol Endoscopy 1983;25:1697-1703.