A forty‐three year‐old woman presented with anorexia, fatigue, and a fifty‐pound weight loss over three months. She reported inability to tolerate food due to nausea, vomiting, and diarrhea with every meal. She denied abdominal pain, hematemesis, melena, and hematochezia. She did endorse vaginal spotting for several weeks. Surgical history included open total hysterectomy and abdominal sacral colopexy with mesh four years prior to presentation. Her exam was negative for abdominal tenderness and lymphadenopathy. Vaginal exam revealed a one centimeter opening in the center of the vaginal cuff and a one centimeter by one centimeter firm, “crunchy”, yellow‐white mass. Complete blood count and basic metabolic tests were unrevealing. Computed tomography scan showed a prominent vaginal cuff and a 1.8 centimeter enhancing oval lesion. Biopsy of the lesion revealed bacterial morphology consistent with Actinomycesassociated with implanted mesh. She was discharged on a 3‐month course of intravenous penicillin with plans to remove the infected mesh. At two‐month follow up visit her diarrhea and appetite had significantly improved and her weight was stable.
Actinomycosis is an indolent disease caused by the slow growing gram positive anaerobic bacteria Actinomyces israelii. The bacteria are normal flora of the oropharynx, gastrointestinal tract, and urogenital tract and become pathogenic with disruption of the mucosal barrier. Twenty percent of infections are abdominopelvic while the rest are orocervicofacial and thoracic. Risk factors for infection include immunosuppression, local tissue damage, and the presence of a foreign body. Most abdominal infections are associated with surgery. Pelvic actinomycosis is most commonly associated with intrauterine contraceptive devices. Because of the slow growth of the pathogen, patients often present years after acquiring the infection. These infections are difficult to diagnose because they often mimic malignancy with nonspecific symptoms of fever, weight loss, and malaise. Fewer than ten percent of cases are diagnosed preoperatively. CT often shows a cystic mass with thickened walls and characteristic disruption of tissue planes as the pathogen often forms sinus tracts. Actinomycosis is diagnosed when biopsy of the infected tissue reveals sulfur granules and gram positive filamentous organisms. Culture is more specific but takes up to three weeks and is positive in less than fifty percent of cases. The yield is limited by previous antibiotic treatment and sample error. New diagnostic studies using PCR are currently in development. Treatment involves high doses of penicillin for six to twelve months and removal of infected foreign bodies.
Abdominopelvic actinomycosis often mimics malignancy. Risk factors include surgery or the presence of foreign materials in the body such as an IUD or vaginal mesh. The astute clinician will recognize that the offending surgery or procedure could have been temporally remote and will include actinomycosis in the differential for at‐risk patients presenting with nonspecific symptoms of weight loss, fevers or fatigue.
To cite this abstract:Dancel R, Caldwell M, Pauley E. An Unusual Pelvic Infection Mimicking Malignancy. Abstract published at Hospital Medicine 2014, March 24-27, Las Vegas, Nev. Abstract 397. Journal of Hospital Medicine. 2014; 9 (suppl 2). https://www.shmabstracts.com/abstract/an-unusual-pelvic-infection-mimicking-malignancy/. Accessed March 31, 2020.