Useful Trick for Discovering Granuloma in Gastric Crohn's Disease
In the present case (a 29-year-old woman complaining of dyspeptic symptoms associated with an increased erythrocyte sedimentation rate and iron deficiency without anemia), the role played by a close collaboration between the gastroenterologist and pathologist was highlighted. Together with an accurate endoscopic report of a picture of varioliform gastritis, the gastroenterologist sent the pathologist the relative endoscopic picture and suggested a possible gastric location of Crohn's disease (Fig. 1A). At the histological evaluation, a typical pattern of chronic disease was recognized, as well as the presence of a strange vascular capillary structure (Katana-like), running parallel to the muscularis mucosae, occupying the space of 2 adenomeres, in a stromal area devoid of specific antral glands (Fig. 1B). On the basis of the macroscopic pattern, the pathologist requested further sections at deeper levels of the gastric sample to explore the reason for the anomalous vascular structure and analyze the discrepancies between the macro and microscopic patterns. In the area of the arcuate vessel, in deeper sections a definite noncaseated, well-formed granulomatous lesion was identified, with histiocytic multinucleated giant cells, revealing gastric Crohn's disease (Fig. 1C). Also in intestinal Crohn's disease, as suggested by Prof. BC Morson, deep cuts into apparently uninvolved rectal samples can reveal granuloma in many cases, solving the diagnostic riddle. The patient underwent colonoscopy and terminal ileoscopy: the presence of a hyperemic area with aphthoid lesions of the terminal ileum suggested an ileal Crohn's disease, confirmed by histology. In Crohn's disease, variable mild architectural abnormalities and epithelioid granulomas are common features while granuloma is a very specific indicator. Crohn's disease can be present anywhere in the gastrointestinal tract but the most common location is the ileocecal region.1,2 Moreover, the diagnosis of gastric Crohn's, which has an incidence of 10% of cases, is almost always obtained later, during staging of an already diagnosed ileal Crohn's disease. The histological diagnosis of Crohn's disease on gastric samples is suggested by the presence of 1) a focal distribution; 2) chronic active inflammatory lesions; 3) the absence of the Helicobacter Pylori (HP) organism; and 4) granuloma. Therefore, gastric Crohn's disease can be difficult to diagnose because the symptoms can mimic many other conditions and no specific laboratory test is available. The great importance of an interdisciplinary approach between the gastroenterologist and the pathologist in the inflammatory bowel disease field is the main message that emerges from this case report, as well as the need to search for focal structural alterations (vessel abnormalities) in the absence of HP infection and make an accurate morphological evaluation.3,4 These focal stromal abnormalities could be a new diagnostic morphologic pattern in gastric Crohn's disease, sharing the same value as focal cryptal architectural abnormalities in intestinal involvement. Since the majority of patients with Crohn's disease lack significant symptoms, the true incidence of the disease depends on whether such pictures are sought for and identified.