Small Bowel Metastsis from Lung Cancer

Abstract

Introduction: Symptomatic small bowel metastasis from primary carcinoma of the lung is considered a rare clinical entity. We report two distinct clinical presentations of non-small-cell lung carcinoma with gastrointestinal involvement. Case 1: A 68 year old Hispanic male with a non-small-cell lung cancer presented to the ED with shortness of breath, fatigue, anorexia, emesis, and dark stools. Physical examination revealed a pale elderly male, with epigastric fullness and crepitations in the right lung field. Laboratory tests suggested severe anemia with Hemoglobin level of 5.2 gm/dl. Upper endoscopy and colonoscopy failed to identify the etiology of the anemia. CT scan suggested a filling defect in the jejunum with suspected intussusception, requiring partial small bowel resection. Histopathology confirmed malignancy consistent with metastasis from the primary non-small-cell lung carcinoma. He deteriorated clinically with worsening metastasis and died within a few weeks. Case 2: A 74 year old Hispanic male presented with left knee pain. He had anorexia, weight loss, fatigue and occasional dark stools. Physical examination revealed a pale elderly male with tachycardia. His hemoglobin was 7.7 gm/dl with fecal occult blood positive. Endoscopies revealed raised, friable, vascular, superficially ulcerated mucosal lesions in the stomach, jejunum, cecum and rectum. CT scan of the chest was noted for 6 cm size right lower lobe lung mass. There was evidence of extensive bone metastasis. Histopathology report from gastrointestinal lesions revealed large cell poorly differentiated carcinoma. He opted for hospice care and died within a few weeks Discussion: Cancers of the lung often disseminate early, but small bowel metastasis of a primary lung carcinoma is rarely encountered, with a reported incidence of 0.5% in one series. Large cell carcinoma is the most common histopathologic type. Usual presentation includes intestinal obstruction, perforation and rarely bleeding and peritonitis. Surgical resection may be pursued in patients with excellent primary tumor control in the absence of concurrent other metastatic involvement. The prognosis for patients with small bowel metastasis of non-small-cell lung carcinoma is poor with reported survival ranging from weeks to months.