Quiz Page January 2010:
A Colonic Mass in a Kidney Transplant Recipient
Article Outline
Clinical Presentation
A 60-year-old woman was admitted for diarrhea and hematochezia. One year ago, she received a deceased donor kidney transplant for end-stage renal disease secondary to diabetes. Other medical history includes colon cancer 16 years before transplant requiring partial colectomy, with pretransplant colonoscopy showing no recurrence of cancer. Human immunodeficiency virus (HIV) serologic test results were negative, and cytomegalovirus (CMV) serologic test results were negative in the recipient but positive in the donor. Immunosuppressive medications included cyclosporine, sirolimus, and prednisone, along with valganciclovir prophylactic therapy. One month before presentation, serum creatinine level was 1.5 mg/dL (133 μmol/L; estimated glomerular filtration rate, 38 mL/min/1.73 m2 [0.63 mL/s/1.73 m2]). She now reports 1 week of diarrhea with blood, as well as nonbilious vomiting. Initial vital signs showed a temperature of 97.2°F, respiratory rate of 18 breaths/min, heart rate of 72 beats/min, and blood pressure of 171/93 mm Hg. Physical examination showed dry skin and mild diffuse abdominal tenderness. Laboratory data included the following values: serum creatinine, 2.7 mg/dL (239 μmol/L); estimated glomerular filtration rate, 19 mL/min/1.73 m2 (0.32 mL/s/1.73 m2); 12-hour cyclosporine trough, 164 ng/mL; and sirolimus, 16.6 ng/mL. Colonoscopy showed a single mass (Fig 1), and a biopsy was performed (Figure 2, Figure 3).
Figure 1.
Colonoscopy findings.
Figure 2.
Hematoxylin and eosin stain (original magnification, ×40).
Figure 3.
Immunohistochemical stain (original magnification, ×40).
■ What is the differential diagnosis of a colonic mass in a solid-organ transplant recipient?
■ Describe the features in Figure 2, Figure 3.
■ What is the pathogenesis of this lesion?
■ What is the appropriate work-up of a solid-organ transplant recipient with this condition?
Discussion
What is the differential diagnosis of a colonic mass in a solid-organ transplant recipient?
A firm sessile polyp with central indentation and patchy erythema (Fig 1) was seen on colonoscopy. Among neoplastic causes, the risk of colon cancer is higher in transplant recipients compared with the general population.1 Primary colorectal lymphoma and posttransplant lymphoproliferative disorder are other considerations in the setting of immunosuppression. Gastrointestinal stromal tumors also have been reported, and Kaposi sarcoma should be in the differential diagnosis, especially if the patient has HIV infection. Among infectious causes, CMV infection has been reported to present as pseudotumors anywhere from the esophagus to the colon. Rich et al2 described 3 cases with discrete mass lesions of the gastrointestinal tract that were indistinguishable from neoplasms, but turned out to be CMV based on immunohistochemical staining of intranuclear inclusion bodies. Tuberculosis, actinomycosis, histoplasmosis,3 Clostridium difficile colitis, and amebic colitis also have presented as colonic masses.
Describe the features in Figure 2, Figure 3
Figure 2 shows a hematoxylin and eosin–stained section of colonic tissue demonstrating multiple enlarged cells containing a single large eosinophilic nuclear inclusion surrounded by an area of clearing. These inclusions are characteristic of infection with CMV. Figure 3 shows positive immunohistochemical staining for CMV in the enlarged cells.
What is the pathogenesis of this lesion?
The strong predilection of CMV for vascular endothelium can result in ischemic mucosal injury and penetration of the virus through the lamina propria to the bowel serosa. Infection also may affect smooth muscle, nervous tissue, and even inflammatory cells. These changes, together with fibrous replacement of the muscularis mucosa and stromal reactivity, may result in the formation of a luminal mass. The characteristic histopathologic features of these inflammatory masses include infiltration of the mononuclear cells, fibroblasts, and vascular proliferation with CMV inclusion bodies.4
What is the appropriate work-up of a solid-organ transplant recipient with this condition?
Gastrointestinal CMV disease is progressive without therapy and associated with rejection in kidney transplant recipients. Korkmaz et al5 reported that in 129 colonoscopies performed between 1996 and 2004 in 89 solid-organ transplant patients for fever and diarrhea, 7 patients showed CMV colitis by histopathologic examination. Six of those patients had normal stool examination findings, and serum CMV immunoglobulin M and pp65 antigen were positive in only 2 patients. These findings show that serologic testing may be insufficient for definitive early diagnosis, especially in mild clinical presentations. Early endoscopy with histopathologic examination of biopsy specimens therefore can provide an accurate diagnosis so that appropriate therapy can be instituted in a timely manner and possibly prolong patient and transplant survival.5
A repeated colonoscopy performed in our patient 6 months after treatment with ganciclovir did not show a colonic mass.
Final Diagnosis
CMV colitis presenting as a colonic mass.
References
- . Gastrointestinal complications in renal transplant recipients. Transpl Int. 2005;18(6):643–650
- . Discrete gastrointestinal mass lesions caused by cytomegalovirus in patients with AIDS: report of three cases and review. Clin Infect Dis. 1992;15(4):609–614
- . Colonic histoplasmosis in acquired immunodeficiency syndrome mimicking carcinoma. Ann Diagn Pathol. 2003;7(1):14–19
- . Cytomegalovirus infection in AIDS presenting as a rectal mass. Am J Gastroenterol. 2000;95(1):327–328
- The role of early colonoscopy in CMV colitis of transplant recipients. Transplant Proc. 2005;37(7):3059–3060
Case provided and authored by Sardar Z. Imam, MD,1 Asadullah Khan, MD,2 Jesse M. Jaso, MD,3 and John R. Foringer, MD,2 1Department of Internal Medicine, 2Division of Renal Diseases and Hypertension, and 3Department of Pathology, University of Texas Health Science Center at Houston, Houston, TX.Address correspondence to Asadullah Khan, MD, Division of Renal Diseases and Hypertension, University of Texas Health Science Center at Houston, MSB 4.148, Houston, TX 77030. E-mail: asadullah.khan@uth.tmc.edu
Support: None.
Financial Disclosure: None.
PII: S0272-6386(09)01258-X
doi:10.1053/j.ajkd.2009.09.009
© 2009 National Kidney Foundation, Inc. Published by Elsevier Inc All rights reserved.
