Primary urachal malignancy: case report and literature review

Abstract

Dear Editor, We present the case of a 38-year-old nulliparous woman who presented with a 3 months history of lower abdominal pain, dysuria and frequency. She denied weight loss, altered bowel habit or PR bleeding. Examination revealed a pelvic mass palpable to the level of the umbilicus. It was firm, non-tender and immobile. Hb was 9.6 g/dl and CA 125 was 18 U/ml. Her liver function tests, urea and electrolytes were within normal limits. Past history included emergency surgery at 3 days of life for Meckels diverticulum, atrial septal defect repair at 7 years of age and an appendectomy at 8 years of age. She had no previous gynae history or family history of breast, ovarian or bowel carcinoma. An abdominal and pelvic CT scan revealed a 9.5 9 7.7 cm midline abdominal mass suspicious for ovarian malignancy (Figs. 1, 2). The mass appeared adherent to the anterior abdominal wall had irregular margins and fat stranding. It indented small bowel loops and possible invasion of the small bowel was suggested. A further multi-cystic lesion was seen in the left adnexa. No pleural effusion or ascites were present. Multiple mesenteric nodes of 1 cm in diameter were present. She was referred to a tertiary gynaecology oncology centre where a laparotomy was performed with a colorectal surgeon present. She was found to have situs inversus of the abdominal organs, an absent right ovary and fallopian tube and normal left ovary and fallopian tube. The tumour was adherent to the anterior abdominal wall and to the bladder posteriorly. A frozen section confirmed metastatic mucinous adenocarcinoma consistent with an ovarian primary. Also present was a healthy appendix although situated in the left iliac fossa. The mass was resected en bloc (Fig. 3) including much of the rectus muscle, the dome of the bladder, two loops of small bowel and a right hemicolectomy was performed. A simple cystic left paraovarian mass was also removed. Histology showed a signet-ring mucinous adenocarcinoma of the urachus (10 cm) extending from the dome of the bladder with full thickness invasion of the small bowel and inflammatory adhesions to large bowel. All bowel, bladder and soft tissue margins were free of tumour. A normal appendix was noted. 31 lymph nodes isolated were free of tumour. The para-ovarian mass showed signet-ring mucinous adenocarcinoma also consistent with metastasis from urachal malignancy. Peritoneal washings were negative. She recovered well postoperatively and was referred to urology for discussion re-adjuvant chemotherapy. The urachus is a midline vestigial remnant located between the dome of the bladder and the umbilicus (Fig. 4). In the foetus the urachus connects the bladder to the allantois. In normal development the allantois is gradually reduced and obliterated with the urachus becoming a fibrous band extending from the anterior bladder dome to the umbilicus. Primary adenocarcinoma of the bladder accounts for less than 1 % of all bladder malignancies, of these 20–39 % are urachal in origin. Urachal adenocarcinoma is more common in men and tends to present in the fifth and sixth decade of life. The common presenting symptoms are haematuria, pain, irritative voiding symptoms and mucosuria. Most urachal malignancies (70 %) are mucin-producing adenocarcinomas, more rarely it is a non-mucin producing adenocarcinoma (15 %). Consistent with other enteric type adenocarcinomas, urachal cancers may express detectable D. Hayes Ryan (&) P. Paramanathan N. Russell J. Coulter South Infirmary Victoria University Hospital, Cork, Ireland e-mail: dee_hayes_ryan@hotmail.com