Distant metastasis from primary lung cancer is mostly seen in the liver, brain, adrenal glands and bones. Small bowel, specifically duodenum is a relatively unusual site for distant metastasis from lung carcinoma. This case reports a rare scenario of upper gastrointestinal bleeding caused by duodenal metastasis by a primary lung adenocarcinoma. A 43-year-old woman presented to the emergency department with complaints of progressive hemoptysis for the past three weeks. Esophagogastroduodenoscopy (EGD) revealed a 2.5 cm x 2.5 cm fungating villous mass-like structure in the first portion of the duodenum, with a normal-appearing esophagus and stomach. Biopsies were performed, which were histologically consistent with poorly differentiated malignant. The immunohistochemical (IHC) staining was consistent with metastatic disease from primary lung adenocarcinoma. Due to its rarity, there are no solidified guidelines for the management of duodenal metastasis from lung carcinoma. Our case was challenging due to the extensive metastasis and low functional status of the patient and was ultimately managed with home hospice.

Case Description/Methods: This is a case of a 50-year-old woman with a history of cervical cancer treated with radiation therapy 20 years ago and recurrent cystitis who was admitted due to 2 month history of CD, decreased urine output, and dysuria. The patient reported more than 5 episodes of watery diarrhea daily associated with abdominal and suprapubic discomfort. Vital signs were remarkable for tachycardia. On physical exam, she was found underweight and malnourished with a non-distended abdomen with high pitch bowel sounds. Labs showed preserved renal function with metabolic acidosis(MA). A urinalysis revealed pyuria and bacteriuria. Fecal leukocytes, stool culture and ova and parasite resulted negative. Empiric therapy for UTI and C. difficile were provided due to recent antibiotic use for recurrent cystitis. After ruling out C. difficile and no improvement of symptoms, loperamide was started without improvement. A CTE was ordered to rule out any structural cause of diarrhea but came unremarkable. Additional workup for less common causes of diarrhea like viral, parasitic and metabolic tests were ordered but all were negative. A colonoscopy was done but no endo-histologic abnormality was found. After 2 weeks, the patient reported an increased frequency of diarrhea and anuria, but renal function remained stable reason for which an enterovesical fistula (EVF) was suspected. A CT cystography was then performed confirming our suspicion. Due to poor nutritional status, the patient was not a candidate for surgery. To divert the urine and decrease the fistula's flow to the ileum, nephrostomies were placed. After 3 days the CD and MA resolved hence, the patient was discharged. Discussion: Here we portray a case of an Ileovesical fistula (IVF) causing CD, recurrent UTI, and severe MA caused by the effect of radiation. It is important to report this case to raise awareness of the importance of the history of radiation in patients with CD to decrease invasive and expensive tests in the diagnostic process. Also, to highlight the benefits of nephrostomies as a tool in the management of IVF and its impact on the quality of life of the patients.

Figure 1. The image on the left shows whitish nodular mucosa in the second portion of the duodenum in Case 1. The image on the right shows abnormal duodenal mucosa in Case 2.