A 50-year-old man comes to the emergency department due to 2 days of malaise, decreased appetite, abdominal discomfort, and bloody stools. The patient had end-stage renal disease and underwent kidney transplantation 4 months ago. He had no major postoperative issues and currently takes mycophenolate, tacrolimus, and prednisone. The patient has a 15 pack-year smoking history but quit several years ago. Temperature is 37 C (98.6 F), blood pressure is 110/70 mm Hg, pulse is 104/min, and respirations are 22/min. Physical examination shows mild abdominal tenderness in the left lower quadrant. Rectal examination is normal. Stool is guaiac positive. Laboratory results are as follows: Atypical lymphocytes are seen on peripheral blood smear. A colonoscopy reveals multiple ulcerations throughout the colon. Which of the following is the most likely diagnosis for this patient?

Question

A 50-year-old man comes to the emergency department due to 2 days of malaise, decreased appetite, abdominal discomfort, and bloody stools.  The patient had end-stage renal disease and underwent kidney transplantation 4 months ago.  He had no major postoperative issues and currently takes mycophenolate, tacrolimus, and prednisone.  The patient has a 15 pack-year smoking history but quit several years ago.  Temperature is 37 C (98.6 F), blood pressure is 110/70 mm Hg, pulse is 104/min, and respirations are 22/min.  Physical examination shows mild abdominal tenderness in the left lower quadrant.  Rectal examination is normal.  Stool is guaiac positive.  Laboratory results are as follows:  Atypical lymphocytes are seen on peripheral blood smear.  A colonoscopy reveals multiple ulcerations throughout the colon.  Which of the following is the most likely diagnosis for this patient?

Quizplus · Accepted Answer

Patients who undergo renal transplantation receive high-dose immunosuppressant medication for several months after surgery, putting them at risk for opportunistic infections. One of the most common opportunistic infections following renal transplantation is cytomegalovirus (CMV). CMV is a widely prevalent herpesvirus that establishes a latent infection after initial inoculation. Most patients remain asymptomatic, but infection may reemerge in patients who are severely immunocompromised. CMV reactivation results in viremia and/or tissue-invasive disease. The gastrointestinal tract is the most common organ system affected, and patients usually manifest symptoms of colitis or enteritis, including fever, malaise, vomiting, bloody diarrhea, and abdominal pain. Laboratory studies often show cytopenias due to bone marrow involvement, and peripheral blood smear typically reveals atypical lymphocytes. atypical lymphocytes Viremia can be present, but end-organ disease can occur in the absence of viremia; biopsy of the affected organ is the gold standard for diagnosis of tissue-invasive disease. Patients with symptoms of CMV colitis typically have multiple, large, shallow erosions or ulcers on colonoscopy. Treatment with antivirals (eg, ganciclovir) and a reduction of immunosuppressant medication is usually required. ulcers (Choice B) Initial infections with both Epstein-Barr virus (EBV) and CMV may cause infectious mononucleosis, and both viruses establish latent infections; however, EBV reactivation is typically associated with malignancies (eg, nasopharyngeal carcinoma, non-Hodgkin lymphoma), not colitis. (Choice C) Although graft rejection can occur after kidney transplantation, graft-versus-host disease is quite rare. Graft-versus-host disease is typically seen in patients who have undergone allogeneic stem-cell transplantation. (Choice D) Patients who have undergone transplantation are at risk for herpes simplex reactivation with resultant tracheobronchitis, esophagitis, pneumonia, and/or hepatitis; colitis is uncommon. This patient is much more likely to have CMV reactivation. (Choice E) Ischemic colitis can cause abdominal pain and bloody stools; however, atypical lymphocytes are not a feature of this disease and endoscopy usually reveals pale mucosa with petechial bleeding, hemorrhagic nodules, or cyanotic mucosa with hemorrhagic ulcers. Educational objectives: Patients who undergo renal transplantations are at risk for cytomegalovirus reactivation with viremia and/or end-organ disease. Gastrointestinal manifestations are common and include abdominal pain, vomiting, bloody diarrhea, and endoscopic evidence of multiple, large, shallow ulcers. Biopsy is the gold standard for diagnosis of tissue-invasive disease.

A 50-Year-Old Man Comes to the Emergency Department Due to 2