Watery Diarrhea and Various and Variable Lesions in the Intestine

Question: A 58-year-old man was admitted to the Gastroenterology Department because of persistent watery diarrhea for 4 months. Four months ago, the patient began to suffer from 8–10 episodes of watery diarrhea per day without an obvious cause, and the diarrhea did not cease with fasting. He denied abdominal pain, nausea, vomiting, fever, and so on. He lost about 15 kg in the past 4 months. He had no history of long-term medication use. Physical examination revealed hyperactive bowel sounds (10 times/min) and bilateral pedal edema. Stool examination showed large numbers of red and white blood cells, negative Sudan III staining, negative acid-fast staining, undetected Clostridium difficile toxin, and undetected Salmonella and Shigella based on the culture method. Laboratory tests revealed hypoalbuminemia (22 g/L), hypokalemia (2.9 mmol/L), hypomagnesemia (0.54 mmol/L), and that hemoglobin decreased from 150 g/L–106 g/L in the past 2 months. The thyroid function test was normal. Thoraco-abdomino-pelvic computed tomography (CT) showed multisegmental localized thickening of the intestinal wall. The patient underwent colonoscopy and gastroscopy examinations at the beginning of the disease course, 2 months after onset, and at admission. The first colonoscopy showed a raised lesion in the transverse colon, and the pathologic examination suggested inflammatory granulation tissue. The second colonoscopy showed edema, hyperemia, and erosions in the transverse colon, descending colon, and sigmoid colon, and sporadic ulcers in ascending colon and cecum. The last colonoscopy and gastroscopy revealed the following findings: esophagus (Figure A); stomach (Figure B); duodenum (Figure C); terminal ileum (Figure D); cecum (Figure E); ascending colon (Figure F); transverse colon (Figure G); descending colon (Figure H); sigmoid colon (Figure I); and rectum (Figure J). Biopsy specimens were taken and histologic findings are shown (Figure K). Immunohistochemistry showed CD2 (partial +; Figure L), CD3 (+; Figure M), CD4 (partial+; Figure N), CD5 (focal+; Figure O), CD7 (+; Figure P), CD8 (focal +; Figure Q), CD20 (-; Figure R), CD21 (-), CD30 (Ki-1)(-), CD56 (-), Ki-67 (index 90%, Figure S), granzymeB (-), TIA-1 (+), and AE1/AE3 (-).