Pulmonary intestinal adenocarcinoma secondary to intestinal metaplasia of bladder: a rare case report.

Intestinal metaplasia (IM) in the esophagus is considered as a risk factor of subsequent intestinal-type adenocarcinoma based on the classical theory of metaplasia-dysplasia-carcinoma. IM rarely occurs in urinary tract and fewer studies have been reported with long-term follow-up in those patients with IM of bladder. Thus, the etiology, pathological characteristics and prognosis of IM of urinary tract remain unclear. In the past, IM was regarded as benign lesions in bladder and there might have no relationship between IM of bladder and potential malignancy. Recently, some studies suggested that IM of bladder might indicate a risk of progression to carcinoma and require active surveillance according to their findings. However, due to limited cases, there has not yet been any systematic review or consensus on the management of IM of bladder. Here we reported a patient diagnosed as pulmonary intestinal adenocarcinoma suspiciously secondary to IM of bladder, without primary gastrointestinal cancer or bladder adenocarcinoma. Receiving lung surgery and adjuvant chemotherapy, the patient had no recurrence after a follow-up of 27 months. Hence, the present case demonstrated that ectopic IM can be a driving factor of adenocarcinoma in other organs, such as pulmonary intestinal adenocarcinoma, and it requires a long-term follow-up with overall examinations.