S6140 Urothelial Cancer: A Rare Cause of Protein Losing Enteropathy

Introduction: Urothelial carcinomas (UC) can spread locally to invade surrounding organs, or metastasize distantly to the lungs, bone or liver. Small bowel metastasis is very rare and have been reported to present with small bowel obstruction. Protein losing enteropathies (PLEs) are characterized by a loss of serum proteins (albumin, immunoglobulins, fibrinogen) through the gastrointestinal tract at a rate that exceeds the livers’ ability to produce and replace them. This can be the result of mucosal injury secondary to inflammation or infiltrative diseases that results in loss of protein-rich serum into the lumen of the gastrointestinal tract, or the result of lymphatic fluid leakage due to lymphatic obstruction or elevated central venous pressure. The presentation can be highly variable and can include limb edema, effusions, as well as other gastrointestinal symptoms such as diarrhea, abdominal pain and bloating due to ascites. We present a case of metastatic bladder cancer and protein losing enteropathy. Case Description/Methods: An 85-year-old man with a history of bladder cancer status post cystoprostatectomy with urostomy in 2019, congestive heart failute, remote CVA, depression, presented to the Emergency room with a 6-month history of generalized weakness and weight loss. He recalls a history of coronavirus disease 2019 9 months prior to presentation and noted progressive loss of appetite, early satiety and 30 lbs weight loss. On examination, he was afebrile, normotensive and appeared thin and cachectic with bilateral 2+ pitting pedal edema. Laboratory testing revealed mild thrombocytopenia (205,000 platelets per microliter), low total protein of 5.8 g/dl and hypoalbuminemia 2.8 g/dl. Lower extremity doppler ultrasound revealed nonocclusive deep vein thrombosis in the bilateral iliac veins and was started on Eliquis. Given weight loss and extensive deep vein thromboses, he underwent a computed tomography angiogram of the chest, abdomen and pelvis which revealed mural thickening of numerous small bowel loops raising a concern for enteritis. He underwent an upper endoscopy which revealed congested appearing duodenal mucosa. Duodenal biopsies confirmed metastatic carcinoma within lymphatics, most consistent with urothelial origin, positive for GATA3, CK7, CK20. An elevated fecal Alpha 1 Antitrypsin clearance confirmed protein losing enteropathy. The cause of his weight loss, hypoalbuminemia was felt to be from metastatic urothelial carcinoma causing secondary intestinal lymphangiectasia and protein losing enteropathy. Discussion: To date, this is the first reported case of bladder cancer presenting as protein losing enteropathy.