A 64-year old woman was admitted to the Gastroenterology Unit of another Hospital for abdominal pain, nausea, weight loss, and recurrent episodes of constipation. She had suffered from intermittent pain located in the right lower quadrant for 2 years, but denied chronic diarrhea. She was diagnosed as having Crohn's disease of the terminal ileum by ileocolonoscopy and histology. An upper gastrointestinal series excluded CD in the upper gastrointestinal tract.
After inductive therapy with azathioprine and corticosteroids, the patient was maintained with mesalazine 500 mg × 4 daily. Prednisone 50 mg/day was added only during acute phases; in the six years following the discharge, 2 episodes of abdominal pain and dyarrhea requiring steroid therapy were recorded. Seven years later the patient was admitted to our Institution for abdominal pain, nausea, iron deficiency anemia, hypoalbuminemia, and intestinal obstruction. On physical examination no masses in the abdomen were noted. Small bowel double-contrast enteroclysis (Fig. ) showed a stricture of the terminal ileum with a thickening of the wall without extravasation of the contrast material. CT scan performed by using intravenous and oral contrast material revealed thickening of the terminal ileum with stranding of the mesenteric fat. There was no clinical evidence of carcinoid tumor so biochemical tests for carcinoid syndrome were not carried out.
Small bowel double-contrast enteroclysis (detail) showing a stricture (arrow) of the terminal ileum with a thickening of the wall.
At operation, there was a stricturing lesion in the last 6 cm of the terminal ileum with proximal dilation. The wall of the affected ileal loop and caecum was thick and fibrous. Resection of the terminal ileum and caecum was performed. The intestinal continuity was obtained with an end-to-end ileocolic hand-sewn anastomosis.
The surgical specimen included 28 cm of the terminal ileum and caecum. Grossly, all the length of surgical resection showed diffuse thickness of the intestinal wall. There was no evidence of malignancy (Fig. ). Histologically, all resected surgical specimen was characterized by deep ulcers, marked proliferation of small lymph nodules involving all layers of the intestinal wall, sometimes with sarcoid-type granulomas and serosal inflammation. Moreover, two malignancies growing together were found in the ileal loop. The first showed glandular differentiation of large cells with round to oval nuclei sometimes with large nucleoli and abundant pale cytoplasm infiltrating the entire wall (pT2N0M0). The latter consisted of quite uniform medium size cells with round nuclei and inconspicuous nucleoli growing in a trabecular or acinar pattern (Fig. ). Only the immunohistochemistry of this latter tumoral population showed strong and diffuse immunoreactivity to neuroendocrine markers such as Chromogranin A and Synaptophisin. All excised mesenteric lymph nodes were negative for malignant cells. The postoperative recovery was uneventful and the patient was discharged in general good condition. At 18-months follow-up the patient, checked by colonoscopy and ileoscopy was well, free from malignancy relapse or recurrence of CD, and with normal 24-hour urinary excretion of 5-hydroxyindoleacetic acid (5-HIAA).
The ileal loop shows an important thickness of the wall with disappearance of the normal mucosal plicae.
Strong immunoreactivity for Chromogranin A of carcinoid tumor infiltrating the muscular layer of the intestinal wall is clearly evident. The deep ulcer of CD is also present. (Magnification: ×25; Chromogen diaminobenzidine).