Metastatic Crohn disease presents microscopically as sterile, noncaseating granulomatous inflammation located primarily in the superficial papillary and deep reticular dermis with occasional extension into the subcuticular fat (Figures 2 through 5).
There are a number of differences between the microscopic findings of primary gastrointestinal Crohn disease and that of MCD.
The histopathologic features of MCD compared to Crohn disease directly involving the skin (ie, perianal, peristomal, perifistular) are similar overall, with anatomic location being the main differentiating feature.
Initially, we found 117 potential hospital- or population-based case-control studies with Crohn disease as cases and identified 39 studies with ulcerative colitis as cases.
The odds ratios per allele for Crohn disease were 2.2 (95% CI, 2.0-2.5) for Arg702Trp, 2.6 (95% CI, 2.2-2.9) for Gly908Arg, and 3.8 (95% CI, 3.4-4.3) for Leu1007fsinsC (Fig.
The odds ratios per allele for Crohn disease were similar for the following subgroup comparisons: northern vs southern Europeans, adults vs children, and familial vs sporadic cases (Fig.
Obliterative muscularization of the submucosa resembles the neuromuscular and vascular hamartoma, considered by Shepherd and Jass (5) as part of the histologic spectrum of Crohn disease. Indeed, these authors mentioned that "we have recently reviewed 50 sequential cases of small intestinal Crohn's disease and histological features identical to those of neuromuscular and vascular hamartoma ...
Intestinal obstruction is an important feature in the natural history of Crohn disease. (6) Several pathogenetic mechanisms have been proposed.
If this were true, "eel in rigor mortis" could be more than a mere historical and graphic description of bowel involved by Crohn disease. (7) Alternatively, OMUS, by minimizing the vasoprotective role of normal submucosa, could cause ischemia contributing to bowel scarring.
Primary gastrointestinal Hodgkin disease in association with Crohn disease is a rare entity.
Because primary gastrointestinal Hodgkin disease cases are so rare, and those arising in Crohn disease are even rarer, the diagnosis should only be made following strict histologic and other criteria proposed by Dawson et al: (a) no superficial lymphadenopathy should be present at the time of diagnosis; (b) chest radiological studies should indicate no involvement of mediastinal lymph nodes; (c) the complete blood count and white cell differential should be within normal limits; (d) gastrointestinal lesion should predominate with or without positive adjacent lymph nodes; and (e) liver and spleen should be free of disease at the time of diagnosis.
In the patients with primary Hodgkin disease complicating Crohn disease reported by Vanbockrijck et al and Kelly et al, immunohistochemical studies with antibodies to CD15 and CD30 confirmed the diagnosis of Hodgkin disease, but the presence of EBV was not investigated.