We previously reported the presence of MUC2, MUC5AC and, for the first time, MUC5B in a 58-year-old male with
pseudomyxoma peritonei (PMP). This is a report on the biochemical and immunohistochemical characterization of
mucin in a 50-year-old female with the same rare illness. A right
oophorectomy and appendicectomy and a resection of the involved omentum were performed. Approximately a litre of crude material in the
sol and gel phases was obtained from the patient during
laparotomy. This was briefly homogenized in 6 M
guanidinium hydrochloride and proteolytic inhibitors and purified by density gradient centrifugation in
caesium chloride. At
laparotomy it was noted that the patient had appendiceal and ovarian masses as well as extensive mucinous deposits in the omentum and peritoneum. A
mucinous adenocarcinoma of the appendix and ovary was confirmed on histology. The cells expressed both sulphated and non-sulphated acidic
mucins. The presence of MUC2, MUC5AC, MUC5B and a-1-acid
glycoprotein was shown by Western blotting and MUC4 by immunohistochemical staining. MUC1 and MUC6 were not detectable in the tissue. The study confirms that MUC2, MUC5AC and MUC5B are produced in the mucus of patients with PMP. The expression of MUC4 in this disease has not been previously reported.