Abstract:
Introduction: Histopathology has played a major role in understanding the pathophysiology and aiding in the diagnosis and management of graft-versus-host disease (GVHD). For all the cases undergoing transplant the post-transplant recovery depends on a multitude of factors and one of the common problems that may impede recovery is acquiring infections like CMV or drug induced injuries(mycophenolate mofetil) etc. GVHD reactions affect almost all the organ systems. The department received biopsy samples of 2 cases of Colitis post bone marrow transplant ,suffering from thalassemia and aplastic anemia. We aimed this study in highlighting the histopathological findings which differentiate cases of primary GVHD colitis versus CMV colitis.
Cases:
Case1:Patient was 10-year male, case of aplastic anemia who underwent a bone marrow transplant and presented with diarrhea. A histopathological biopsy sample from duodenum was sent to the department. Microscopic examination of the biopsy tissue showed biopsy fragment with large areas showing crypt drop out, focal ulceration, crypt destruction with apoptotic bodies and regenerative atypia focally. This was accompanied by fair number of eosinophils in Lamina propria, lymphocytes and neutrophils. Occasional intranuclear inclusion mimicking CMV inclusion was also seen.A diagnosis of CMV colitis with GVHD was rendered and IHC advised for confirmation.
Case2:8 year male case of Thalassemia post BMT suffering from persistent diarrhea. Biopsy sent twice from rectal and colonic mucosa showed variable degree of crypt dropout, apoptotic debris and reactive atypia. Lamina propria showed inflammation comprising of lymphocytes, plasma cells and few eosinophils .No viral inclusions were noted in both the biopsy specimens. IHC for CMV was negative in both the cases. The first biopsy specimen from colon was Modified Lenner Sale Grade 1,Myersons Grade 1 while the follow up biopsy was Modified Lenner Sale Grade 1,Myersons Grade 2,indicating persistent GVHD features on histopathology.
Results: On comparing the histopathological features of the 2 cases it is clear that while features like crypt loss, crypt destruction, reactive atypia can occur in both CMV and GVHD inflammation comprising of neutrophils and viral inclusions are seen with CMV infection per se while absence of neutrophils favours GVHD.IHC is confirmatory for CMV infection. Presence of eosinophils may be there in GVHD as well as drug induced injury as in case with Mycophenolate mofetil.
Conclusion: Histopathological clues on biopsy specimen are extremely useful diagnostic tool with specific features which can help a histopathologists in diagnosing GVHD from CMV colitis in patients post bone marrow transplant.
