RESUMEN
INTRODUCTION: Adenocarcinoma of the small bowel is a rare gastrointestinal neoplasm usually affecting the distal duodenum and proximal jejunum. Because of their rarity and poorly defined abdominal symptoms, a correct diagnosis is often delayed. CASE OUTLINE: We present a 43-year-old woman admitted at the Clinic for Endocrinology due to a large tumor (over 7 cm) of the left adrenal gland.The tumor was detected by ultrasound and confirmed by CT scan.The patient complained of abdominal pain in the left upper quadrant, fatigue and septic fever. Normal urinary catecholamines excluded pheochromocytoma. The endocrine evaluations revealed laboratory signs of subclinical hypercorticism: midnight cortisol 235 nmol/L, post 1 mg - overnight Dexamethasone suppression test for cortisol 95.5 nmol/L and basal ACTH 4.2 pg/mL. Plasma rennin activity and aldosterone were within the normal range. Surgery was performed. Intraoperative findings showed signs of acute peritonitis and a small ulceration of the jejunum below at 70 cm on the anal side from the Treitz's ligament. Adrenal glands were not enlarged. Patohistology and immunochemistry identified adenocarcinoma of the jejunum without infiltration of the lymphatic nodules. The extensive jejunal resection and lavage of the peritoneum were performed. Due to complications of massive peritonitis, the patient died seven days after surgery. CONCLUSION: Poorly defined symptoms and a low incidence make the diagnosis of small bowel carcinoma, particularly of the jejunal region, very difficult in spite of the new endoscopic techniques.