Pelvic actinomycosis

Abstract

Abstract Background Actinomycosis is a rare infectious disease caused by Actinobacteria. It has a wide spectrum of presenting symptoms depending on anatomical location and can occasionally mimic pelvic malignancy and cause diagnostic difficulty. Case A female in her seventies presented with altered bowel habit, anorexia and abdominal discomfort with a history of diverticulosis. CT-AP revealed a sigmoid lesion causing large bowel obstruction. She underwent a laparoscopic defunctioning sigmoid loop colostomy and limited sigmoidoscopy. Subsequent endoscopy showed no dysplastic change but obvious stricturing. A diagnosis of locally perforated diverticular disease was made. Subsequent imaging showed rapid progression with hydroureter and hydronephrosis, now suggesting locally perforated sigmoid tumour or gynaecological malignancy. Tumour markers were normal. She underwent surgical exploration and resection. Specimen evaluation revealed Actinomyces likely originating from diverticular disease. Treatment involved long-term antibiotics for 12 months. Conclusion Pelvic Actinomyces is a difficult diagnosis to make on clinical and radiological findings. It should be considered in differential diagnoses of progressive pelvic lesions.