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cytomegalovirus ( cmv ) infection of the gastrointestinal tract is seen in up to 40% of patients with acquired immunodeficiency syndrome ( aids).1 although frequently presenting as ulcerative lesions resulting in erosive esophagitis , gastritis , or colitis , nonulcerative presentations of cmv in the gastrointestinal tract have been reported.2,3 kaposi s sarcoma and lymphoma are the most common cause of discrete mass lesions in the alimentary tract of individuals with aids.1,4 we present a rare case of a discrete colonic mass secondary to cmv infection in a patient with aids .
a 38-year - old hispanic male with a past medical history of aids on highly active antiretroviral therapy ( haart ) , diabetes mellitus , and stage 5 chronic kidney disease on hemodialysis presented to the medical emergency room with complaints of bright red blood per rectum and abdominal pain .
he had noticed bright red blood intermixed with stool present with every bowel movement for two days .
he also experienced dull intermittent pain in the right upper quadrant of the abdomen during this period .
the patient denied any unintentional weight loss , anorexia , diarrhea , fatigue , or tenesmus .
physical examination was remarkable for pallor and mild tenderness in the right upper quadrant without rigidity or guarding .
digital rectal examination did not reveal any hemorrhoids , mass lesions , or evidence of gross bleeding .
laboratory evaluation was significant for hemoglobin of 8 g / dl with hematocrit of 24% .
his plasma human immunodeficiency virus rna level was undetectable , and cd4 t lymphocyte count was 410 cells / mm . computed tomography of the abdomen revealed no significant abnormalities .
the patient was admitted to the medical floor where his haart was continued , and he underwent esophagogastroduodenoscopy and colonoscopy .
the esophagogastroduodenoscopy was unremarkable , but colonoscopy revealed a 4  5 cm friable mass with mucosal ulcerations in the ascending colon near the hepatic flexure suspicious for neoplasm ( figure 1 ) .
surgical pathology showed colonic mucosa with extensive granulation tissue and acute inflammatory cells suggestive of colitis . within the granulation tissue were endothelial cells and fibroblasts with basophilic intranuclear inclusion bodies suggestive of cmv infection ( figure 2 ) which was confirmed by immunohistochemistry staining for cmv antibodies ( figure 3 ) .
there was no histological evidence of spindle cells with neovascularization , or lymphocytic proliferation with plasmacytic differentiation suggestive of kaposi s sarcoma or lymphoma , respectively .
repeat colonoscopy after treatment showed complete resolution of the mass ( figure 4 ) , with significant clinical improvement .
cmv is a double - stranded dna virus of the herpesviridae family that frequently infects both immunocompetent and immunocompromised hosts .
serologic evidence of prior infection can be seen in nearly 60% of all individuals , often remaining clinically silent.2 in immunocompromised individuals , especially those with aids , cmv infection may involve different organ systems , including the gastrointestinal tract , resulting in significant morbidity . despite the declining incidence of most opportunistic gastrointestinal infections in patients with aids since the advent of haart , cmv coinfection of the gastrointestinal tract is still clinically present.5 cmv infection is present in the alimentary tract of approximately 15%40% of individuals with aids.1 the gastrointestinal manifestations may occur with reactivation of latent disease , secondary to diminishing immune function.1,2 the most frequent clinical presentations of gastrointestinal infection with cmv include erosive esophagitis and colitis .
rarely , bowel obstruction , perforation , toxic megacolon , and gastrointestinal hemorrhage have been reported , often requiring surgical intervention.6 colonic involvement of cmv may present clinically with fever , abdominal pain , profuse diarrhea , weight loss , and gastrointestinal hemorrhage , often warranting endoscopic evaluation for prompt diagnosis.7 endoscopic findings of cmv infection may demonstrate mucosal erythema , erosions , ulcerations , and submucosal hemorrhage.6 cmv infection in the colon may also mimic ischemic colitis in appearance due to interstitial necrosis of colonic mucosa , secondary to involvement of endothelial cells.8 colonic involvement of cmv can be diffuse or limited to one particular part of the bowel . in nearly 25% of individuals with cmv colitis , colonic mucosa may appear endoscopically normal , so biopsies should be taken from multiple areas of bowel if cmv infection is suspected.6 rarely does colonic involvement of cmv result in a discrete mass lesion.1,4 a discrete mass lesion of the gastrointestinal tract in patients with aids is frequently caused by a malignant neoplasm .
the most frequent malignancies of the gastrointestinal tract in patients with aids are kaposi s sarcoma and lymphomas , accounting for nearly 95% of all identified malignancies.9,10 infrequent causes of gastrointestinal mass lesions in patients with aids may include infectious processes , such as tuberculosis , toxoplasmosis , histoplasmosis , and cmv infection.1114 fan et al retrospectively analyzed 25 cases of patients with aids who underwent endoscopic evaluation for gastrointestinal complaints , such as abdominal pain , diarrhea , and hemorrhage . of the 25 patients , six were found to have discrete colonic masses . despite similar clinical and endoscopic presentations ,
three patients were found to have malignancy , and the other three were found to have a mass lesion caused by an infectious etiology based on histopathologic evaluation .
this study emphasizes that , despite malignancy being a common cause of colonic mass lesions in patients with aids , a thorough endoscopic evaluation with histological examination of the lesions is needed to rule out a possible infectious etiology.14 colonic mass lesions due to malignancy that are noted on endoscopy are often indistinguishable from those caused by cmv infection .
however , they may also appear as a solitary colonic mass . in rare instances ,
vascular proliferation of cmv infection results in a mass - like lesion grossly resembling a neoplasm on endoscopic evaluation.15 the diagnosis of cmv infection of the colon relies heavily on histolopathological examination , and may reveal a variety of findings .
cells infected by cmv are often larger than adjacent cells ( cytomegaly ) , and may have a thickened nuclear membrane along with granular intracytoplasmic inclusions.16 basophilic intranuclear inclusion bodies surrounded by a clear halo , giving rise to the characteristic 
owl s eye  appearance of the cell , are suggestive of active cmv replicating nucleoprotein cores.16 despite typical histological findings suggestive of cmv infection , immunohistochemistry is often required to confirm the diagnosis .
kandiel et al suggest that nearly 40% of patients with gastrointestinal cmv infection do not demonstrate typical inclusion bodies on standard hematoxylin and eosin staining , and the use of immunohistochemical staining can increase sensitivity to greater than 90%.16,17 medical management is the mainstay of treatment for cmv infection in the gastrointestinal tract .
ganciclovir and foscarnet are antiviral agents demonstrated to be active against cmv , and clinical improvement of patients treated may be observed in up to 90% of cases.6 in the case described , ganciclovir therapy resulted in marked clinical improvement and complete resolution of the colonic mass on subsequent colonoscopy .
although frequently caused by neoplasm , infectious processes such as cmv must also be considered as a cause of a discrete colonic mass in patients with aids .
if cmv infection is identified , medical therapy often results in significant clinical improvement , and possible resolution of a colonic mass if present .
cytomegalovirus ( cmv ) infection of the gastrointestinal tract occurs in both immunocompromised and immunocompetent hosts . often presenting as ulcerative lesions 
 , cmv infection rarely presents as a mass lesion in the gastrointestinal tract . 
 we present a case of a discrete colonic mass caused by cmv infection in a patient with acquired immunodeficiency syndrome ( aids ) . 
 this case illustrates that an infectious process such as cmv should be considered along with malignancy as the etiology of a mass lesion present in the gastrointestinal tract of patients with aids .