INTRODUCTION
Cytomegalovirus (CMV) commonly causes gastrointestinal lesions, particularly in immunosuppressed
patients or in patients with inflammatory bowel disease. Most commonly, these lesions
present as ulcerations or erosions.[1] Rarely, CMV colitis can present as a discrete mass that grossly mimics adenocarcinoma.[2],[3],[4] Even more uncommon, and never reported before, is CMV colitis presenting as a rectal
mass that induces rectal prolapse. We present a case of CMV colitis presenting as
a mass lesion leading to rectal prolapse, in a patient on immunosuppression.
CASE REPORT
A 59-year-old female was seen in our gastroenterology clinic for rectal bleeding and
a sensation of a “mass” protruding through the anus. The patient received a heart
transplant 14 years prior in the setting of ischemic cardiomyopathy and was taking
cyclosporine, mycophenolate, and prednisone for immunosuppression. She was also taking
valacyclovir 500 mg/day for CMV prophylaxis. Physical examination was notable for
intermittent full-thickness protrusion of the rectum compatible with rectal prolapse.
Laboratory assessment was notable for an elevated carcinoembryonic antigen (CEA) of
6.6 ng/mL. Polymerase chain reaction of the blood was negative for CMV.
A colonoscopy was performed, which demonstrated a 2 cm mass in the rectum [Figure 1]. Endoscopically, the lesion was most concerning for rectal adenocarcinoma. A biopsy
was performed.
Figure 1: Colonoscopy demonstrating a 2 cm circumferential mass in the rectum
Pathology of the mass demonstrated severe active colitis with ulceration and viral
cytopathic change in the endothelial and epithelial cells [Figure 2]. An immunohistochemical stain for CMV was positive [Figure 3]. There was no evidence of malignancy. These findings were consistent with a diagnosis
of CMV colitis.
Figure 2: Rectal mass biopsy stained with Hematoxylin and Eosin demonstrating severe active
colitis and viral cytopathic change in the epithelial and endothelial cells
Figure 3: Immunohistochemical stain for Cytomegalovirus demonstrating positive cells infected
with Cytomegalovirus
The patient was started on valganciclovir 450 mg daily for CMV colitis. Follow-up
flexible sigmoidoscopy revealed that the prior mass had healed. There was note of
punctate erythema but biopsies were negative [Figure 4]. A repeat biopsy demonstrated reduced inflammation with an absence of CMV-infected
cells. With resolution of the mass and prevention of constipation, the patient's symptoms
of rectal prolapse also significantly improved. After 14 months, with both radiographic
and pathologic resolution of her infection, her valganciclovir was discontinued.
Figure 4: Follow‑up flexible sigmoidoscopy 11 months after diagnosis demonstrating resolution
of the mass with surrounding biopsy‑negative punctate erythema
DISCUSSION
The most common gastrointestinal lesions from CMV include ulcerations, erosions, perforations,
hemorrhage, and inflammatory pseudotumors.[1] Rectal prolapse is a rare manifestation of CMV colitis, which has previously been
reported only once in a child with HIV.[5] CMV colitis presenting as a rectal mass that mimics rectal adenocarcinoma is also
a rare phenomenon. There are few reported cases in the literature.[2]-[4],[6] In these documented cases, as in our patient, initiation of antiviral therapy led
to regression of the rectal mass. This is the first report of CMV colitis presenting
as a rectal mass and leading to rectal prolapse.
Immunosuppression is a well-documented risk factor for CMV colitis with HIV/AIDS or
transplantation being the two greatest risk factors.[1] There are reports of patients with HIV presenting with discrete gastrointestinal
mass-like lesions caused by CMV.[6] As noted above, our patient was on a multidrug immunosuppressive regimen to prevent
transplant rejection.
As opposed to CMV infection, which is diagnosed by isolating CMV DNA from the serum,
CMV disease is defined as clinical findings or organ dysfunction with evidence of
CMV infection.[7] CMV prophylaxis has been shown to be effective at reducing the rates of CMV disease
particularly in donor positive, recipient negative heart transplant patients.[7],[8] While controlled studies are lacking, meta-analyses have shown that universal prophylaxis
can prevent between 58% and 80% of cases of CMV disease. The ideal agent, dose, and
duration are not agreed upon; however, valacyclovir has been shown to be effective
in heart-transplant patients.[9],[10] Despite low-dose prophylaxis, our patient still presented with clinical evidence
of CMV disease, which underscores the risk of developing the disease even with preventive
treatment. For treatment of established CMV disease, IV ganciclovir and oral valganciclovir
have been shown to be equally effective in transplant patients.[9]
Our patient also presented with a mild elevation of the CEA tumor marker. Benign conditions
of the gastrointestinal tract, including ulcerative colitis and colonic polyps, are
associated with mild CEA elevations.[11] Relevant to our case, a similar patient with CMV colitis presenting with a colonic
mass also demonstrated a mild CEA elevation.[4]
In summary, we present a case of a patient on chronic immunosuppression with rectal
prolapse who was found to have a rectal mass on colonoscopy, with an endoscopic appearance
initially concerning for malignancy. However, pathology confirmed CMV colitis as the
etiology, and the mass has resolved with antiviral therapy.
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