An Unordinary Recurrence of Urothelial Bladder Carcinoma in the Colon Presenting as Hematochezia

Abstract

The conventional route of recurrence and metastasis in primary urothelial cell carcinoma of the bladder is through lymphatics and hematogenous system with regional lymph nodes, lungs, liver, brain and bone being the most commonly involved sites. Invasive urothelial cancers could also spread locoregionally to surrounding organs including female genital tract, prostate and gastrointestinal tract especially colo-rectum. However, recurrence of this cancer inside the colon in the absence of locoregional invasion, and after achieving complete long-term remission is extremely unusual. A review of the literature revealed a single case reported by Yang et al. of an urothelial cancer recurrence in the colon with mixed urothelial/colonic malignant pathology [1]. Herein we report the second case, to our knowledge, of an urothelial cell bladder carcinoma that recurred inside the colon in the form of a mass causing hematochezia, which on pathology and immunohistostaining proved to be primarily of urothelial rather than colonic origin. 67 year old male heavy smoker with stage III (T3a, N0, M0) transitional cell carcinoma of the bladder had undergone radical cystectomy, neo-bladder reconstruction and adjuvant chemotherapy following initial diagnosis. He poved repetitively to have no evidence of disease until he presented 4 years later with intermittent hematochezia and anemia. Colonoscopy revealed a fungating, ulcerated mass in the sigmoid colon suggestive of a primary colon cancer (fig 1). Pathology disclosed high grade/poorly differentiated carcinoma invading the colonic mucosa that surprisingly favored an urothelial origin. Upon further immunostaining, final diagnosis of a metastatic high-grade urothelial carcinoma was confirmed by positive cytokeratin (CK) 7 stain (specific for urothelial cells) and negative villin and CDX2 stains that are both specific for gastrointestinal differentiation (fig 2). CT scan of abdomen and pelvis, and PET scan did not reveal any other sites of cancer recurrence. Patient received a tailored chemotherapy and responded appropriately.Figure 1Figure 2This case illustrates a rare kind of recurrence of urothelial cancer in the form of a colonic mass resembling primary colon cancer. This unordinary way of recurrence could pose a clinico-pathological diagnostic challenge in distinguishing this disease treated basically with chemotherapy, from a primary colon cancer managed primarily by surgical resection. Immunohistochemical stains are essential for an accurate diagnosis. Heightened awareness is of utmost importance in such patients with history of urothelial cancer in order to appropriately tailor further treatment strategies that differ between primary and secondary colonic tumors.