Primary signet ring cell carcinoma of the bladder: a report on 10 cases.

Primary signet ring cell cancer of the urinary bladder is a rare tumour with some 70 cases reported to date. We report on ten additional cases with long-term follow-up. All 713 primary bladder tumours in western Sweden diagnosed during a 2-year period were prospectively registered and followed and all the histopathological material reviewed. A clinical and histopathological review of 816 bladder tumours from the files of the Oncology Clinic treated between 1962 and 1989 was performed. An incidence of primary signet ring cell carcinoma of 0.6% was found. Three out of five patients who were worked up as a result of an occasional episode of macroscopic haematuria were tumour-free 2, 5 and 14 years, respectively, after radical transurethral resection. Seven patients died of the disease after 5-26 (median 19) months. Our study and a review of the literature indicate that the majority of patients with primary signet ring cell carcinomas are diagnosed at an advanced stage and survival is poor. However, some patients with small tumours at diagnosis were tumour-free after transurethral resection. Radiotherapy was ineffective in most cases. Systemic chemotherapy is of no benefit.