Colovesical Fistula As An Uncommon Presentation Of Metastatic Lung Cancer.

Colovesical fistula is an atypical communication between the colon and the bladder. The most common causes of colovesical fistula are diverticulitis, inflammatory bowel disease, lymphoma and complication from radiation therapy. Patients with colovesical fistula present with recurrent urinary tract infections (UTI), dysuria, frequency, abdominal pain, pneumaturia, faecaluria, and hematuria. We present a case of a patient with stage IV lung adenocarcinoma presented with abdominal pain, dysuria, and faecaluria who was found to have a colovesical fistula. Although colovesical fistula may be sequelae of advanced colon or bladder cancer, it is a very uncommon presentation of metastatic cancer from distant sites. Our case is the first to show that colovesical fistula may present from metastatic lung adenocarcinoma. Clinical awareness of this very unusual presentation of metastatic cancer can lead to faster diagnosis and treatment, possibly minimizing excessive use of antibiotics.