Bizarre stromal cells in ischemic bowel disease.

The presence of bizarre stromal cells has been reported in gastrointestinal and extraintestinal lesions. We describe, for the first time, the presence of bizarre stromal cells with a cytomegalovirus (CMV)-like appearance or ganglion-like cells in 3 cases of ischemic colitis. The 3 patients were males ranging in age from 62 to 78 years, showed varying degrees of cardiovascular insufficiency, and were diagnosed with ischemic colitis. Colonic biopsies showed changes of ischemic colitis of variable severity. Common to all 3 cases, within the granulation tissue, stromal cells showed a broad spectrum of morphologic alterations, ranging from just nuclear enlargement to striking atypical features, large pleomorphic, hyperchromic nuclei, and eccentric prominent nucleoli. Occasionally, these cells displayed an eosinophilic oval nuclear inclusion, surrounded by a clear halo, resembling CMV inclusions. In conclusion, the etiopathogenesis of these cells can be partially explained by hypoxia, inflammation, regeneration/repair, and cell turnover alone or, more probably, in combination in the granulation tissue response to injury. The morphologic spectrum of bizarre stromal cells and ganglion-like cells suggests an obvious differential diagnosis, which includes carcinoma and sarcoma. The finding of enlarged cells with eccentric intranuclear eosinophilic inclusions requires the exclusion of CMV. However, immunohistochemistry, together with an awareness of those atypical stromal cells, can occur in the setting of ulceration and/or polypoid lesions, preventing an incorrect diagnosis.