Mucinous adenocarcinoma arising in a giant urachal cyst associated with pseudomyxoma peritonei and stromal osseous metaplasia

Abstract

An unusual urachal lesion, which is a mucinous adenocarcinoma arising in a giant urachal cyst and is associated with pseudomyxoma peritonei and stromal osseous metaplasia of the cyst wall, was examined in a 45-year-old male. The cyst was encapsulated, measured 22 x 20 x 20 cm and weighed 3800 g. The unilocular cavity was filled with mucin. Most of the cystic cavity was lined with tall, simple or stratified columnar epithelium with a focus of papillary projection into the cavity. These findings suggest that this cystic lesion represents cystadenoma rather than a simple cyst. Foci of invasive moderately differentiated mucinous adenocarcinoma were detected in the area of macroscopic papillary fronds. Carcinoembryonic antigen and CA19-9 were immunohistochemically positive for tumor cells and their serum levels were also elevated. Stromal dystrophic calcification was extensively observed in the cyst wall with foci of osseous metaplasia. Mucinous implants, which histologically demonstrated adherent mucinous masses without epithelial components on the surface, were observed in the pelvic and abdominal cavity, indicating pseudomyxoma peritonei.

Unusual origins of pseudomyxoma peritonei

“…Segmental resection, however, brings tumor of the bladder dome in open contact with the peritoneal cavity, providing the way for peritoneal seeding. Nine other such cases resulting in pseudomyxoma peritonei have been reported in the international literature [13,14].…”

“…The majority of cases are associated with appendiceal and ovarian tumors [1][2][3]. Sporadically this condition is associated with tumors of colon and rectum [4], lung [5], breast [6], pancreas [7,8], stomach [4,9], gallbladder and bile ducts [10], fallopian tubes [11,12], urachus [13,14], urinary bladder, and small intestine [4], whereas another report [15] has attributed the disease to retained rectal tissue after proctocolectomy for ulcerative colitis. Herein, we report on two cases with rare origins of this entity.…”

Pseudomyxoma peritonei due to mucinous cystadenocarcinoma in situ of the urachus presenting as an inguinal hernia

“…It has been reported only seven times since 1966 according to the MEDLINE literature database. [4][5][6][7][8][9][10] In one patient, 4 pseudomyxoma peritonei was associated with the local recurrence of urachal mucinous adenocarcinoma. In two patients, 5,6 it was described as peritoneal mucinous carcinomatosis that resulted from invasive urachal adenocarcinoma.…”

Pseudomyxoma Peritonei Originating from Urachus—Case Report and Review of the Literature

“…In an important proportion of cases (42%), elevated serum carcinoembryonic antigen and carbohydrate antigen 19-9 are present. Both markers are not disease-specific, but remain useful and recommended for primal diagnosis, evaluation of cytoreduction, and postoperative follow-up 28,35,45 .…”