A Case of Plasmacytoid Variant of Bladder Cancer Mimicking Gastrointestinal Cancer

Abstract

We report our experience with a case of plasmacytoid variant of bladder cancer in which bowel obstruction due to peritoneal dissemination was the initial symptom.

A 75-year-old male patient presented with abdominal pain. An abdominal CT scan showed a colonic dilatation with an obstructive origin in the transverse colon, which was thought to be primary in the stomach or transverse colon. Since the tumor was unresectable, we performed a palliative bypass between the ileum and transverse colon followed by chemotherapy. The patient responded temporarily, but his condition worsened, and an additional upper and lower gastrointestinal endoscopy demonstrated no obvious neoplastic lesion. An additional abdominal CT scan revealed a thickened bladder biome, and so a cystoscopy was performed. Although there was no obvious invasive carcinoma in the bladder mucosa, transurethral resection of the same area confirmed the diagnosis of plasmacytoid variant bladder cancer. His condition deteriorated rapidly, and palliative care was decided. He died at a hospital to where he was transferred.

In the diagnosis and treatment of malignant tumors, we should make efforts to add findings and examinations from other fields. Even when peritoneal dissemination precedes and intestinal obstruction was the first symptom, it is important not to assume that gastrointestinal cancer should be the primary tumor, but to also differentiate between bladder cancer and plasmacytoid variant bladder cancer as in this case.