Abdominopelvic Actinomycosis: spectrum of Imaging Findings and common mimickers.

Abdominopelvic Actinomycosis: spectrum of Imaging Findings and common mimickers. Poster No.: C-1375 Congress: ECR 2011 Type: Educational Exhibit Authors: M. Giannila, A. J. Van Der Molen, P. Maniatis, A. Van Es, C. 1 2 1 1 1 2 2 Triantopoulou ; Athens/GR, Leiden/NL Keywords: Abdomen, Gastrointestinal tract, CT, MR, Abscess delineation, Abscess, Infection DOI: 10.1594/ecr2011/C-1375 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 27

Learning objectives To present the different aspects of Abdominopelvic actinomycosis on crosssectional imaging and indicate discriminative findings from other inflammatory or neoplastic diseases. Background Actinomycosis is a rare suppurative disease characterized by progressive, chronic, granulomatous infection caused by an anaerobic Gram-positive bacterium, Actinomyces israelii. It may manifest as fistula, sinus, inflammatory pseudotumor, or abscess formation. Its capacity to invade surrounding tissues and to form masses often leads to misdiagnosis. The three main clinical forms of this disease are cervicofacial, thoracic, and abdominopelvic. The cervicofacial region accounts for 50% to 65%, followed by abdomen (20%). Actinomyces can normally inhabit colon, but requires injury to the normal mucosa to penetrate and cause disease. Predisposing factors may include appendicitis and diverticulitis, gastrointestinal perforations, previous surgery, foreign bodies, or neoplasia. Pelvic actinomycosis has recently become more prevalent and is associated almost exclusively with women who use IUDs. The radiology, pathology and infectious diseases databases of two hospitals, one university and one general, were searched for cases of abdominopelvic actinomycosis. All selected cases and Computed tomography studies are presented and discussed focusing on possible differential diagnostic criteria from other similar conditions. Confirmation of the diagnosis of actinomycosis was done by histopathology in all cases. Images for this section: Page 2 of 27

Fig. 1: Figures 1-2: An inflammatory mass involving the right adnexa and the sigmoid region is seen. There is also extensive inflammatory infiltration of the pelvic fat anteriorly and some loops of small bowel are also involved. Page 3 of 27

Fig. 2: Figures 1-2: An inflammatory mass involving the right adnexa and the sigmoid region is seen. There is also extensive inflammatory infiltration of the pelvic fat anteriorly and some loops of small bowel are also involved. Page 4 of 27

Imaging findings OR Procedure details Patient 1 Female 35 years old, presented with abdominal pain, changed bowel habits and mild leukocytosis. The patient had been wearing IUD for 5 years. On CT scan an inflammatory mass involving the right adnexa and the sigmoid region was revealed. No diverticulosis was evident. There was extensive inflammatory infiltration of the pelvic fat anteriorly and some loops of small bowel seemed to be also involved (figures 1, 2). No ascites or lymph nodes were present. A right tuboovarian abscess was considered in the differential diagnosis, but the extensive inflammatory infiltration could not be explained. This abscess was drained. Colonoscopy showed compression of the sigmoid colon from outside but no evidence for a malignancy. The IUD was removed and actinomyces was cultured. After the final diagnosis, she received penicillin i.v and surgery was avoided. Patient 2 Female 49 years old, presented with abdominal pain and distention, fever and severe leukocytosis. The patient had been wearing IUD for 9 years. CT scan was performed after administration of rectal contrast. Bowel compression was evident as well as thickening of the sigmoid colonic wall (figures 3, 4). Many "cystic" lesions appeared in the pelvic area while the ureters were also involved resulting in mild hydronephrosis (figures 5, 6). Severe endometriosis was the initial diagnosis, but a colonic malignancy was also discussed in the differential diagnosis. Explorative laparotomy was performed. A mass lesion was found adjacent to the uterus, the ovaries were cystically enlarged and liver lesions were obvious. Small pelvis lesion showed granulating infection but no Actinomyces could be cultured. Liver lesions showed infection with Actinomyces Naeslundii. No malignancy was found in any biopsy. IUD was removed and the patient received high-dose of Penicillin G i.v. and metronidazole. The treatment continued with Amoxycillin orally for 9 months until normalization of CT findings. Page 5 of 27

Patient 3 Female 33 year old, presented with peritonitis. She underwent uncomplicated surgery for appendicitis three months before. Many abscesses were evident on CT involving the pericecal and pelvic area, while there was also bowel wall thickening, inflammatory infiltration of the pelvic fat, and extensive small bowel dilatation (figures 7, 8, 9). Intestinal perforation was discussed in the differential diagnosis as well as complications related to the previous surgery. She was operated for a second time after the final diagnosis and extensive drainage was performed as well as partial enterectomy. Patient 4 A 50 year old female patient was admitted to the emergency department complaining of fever, weight loss, anorexia and constipation. On admission she presented severe lower abdominal pain, with a palpable mass. She was receiving antibiotics for a suspected urinary infection with no symptoms relief, while the abdominal mass was 3 enlarging. Laboratory results revealed leukocytosis of 23,900/mm. The CT scan examination revealed a very large abscess of the left lateral abdominal wall, as well as many intraabdominal smaller abscesses in the pelvic area above the uterus and the sigmoid colon (figure 10 on page 17). Perienteric infiltration was also observed as well as omental involvement. She underwent surgery and upon receiving the pathology report systemic intravenous penicillin treatment was administered for 14 days. Patient 5 Man 55 year old, presented with mild right lower abdominal pain. The laboratory results were unremarkable. He underwent emergency surgery five months ago due to penetrating abdominal trauma. On CT scan a mass like heterogenous large lesion was revealed in the right pelvis adjacent to a bowel segment that seemed intact but slightly compressed. No lymph nodes or vessels involvement were revealed (figure 11 on page 18). There were also no signs of inflammatory pelvic infiltration. In the differential diagnosis a complication related to the previous surgery like a retained foreign body was discussed. Correct diagnosis was made only after surgery. Page 6 of 27

Patient 6 Female 60 years old, presented with abdominal pain, fever, coughing and severe leukocytosis. She underwent hysterectomy one year before due to large leiomyomas. On the abdominal CT scan many abscesses were revealed in the right pelvis, mild inflammatory fatty infiltration was seen and small pelvic lymph nodes were noted (figure 12 on page 19), while on the thoracic CT scan a small abscess was found in the right upper lobe and atelectasis in the left lower lobe associated with pleural effusion (figure 13 on page 20). TBC infection was considered as a probable diagnosis. After FNA and laboratory investigation abdominal actinomycosis was revealed with thoracic dissemination. The patient received penicillin treatment and the need for surgery was obviated. Patient 7 Female 51 years old, wearing an IUD, presented with abdominal pain of one month duration, fever and weight loss. Inflammatory markers (ESR and CPR) were elevated. On the emergency department diverticulitis was diagnosed. However her complaints persisted after a fluid diet. Gynecological consultation resulted in removal of the IUD which was in situ for 20 years. Actinomyces was cultured from this IUD. On CT examination many collections and abscesses were found in the pelvis and there was also inflammatory involvement of the fat and mild small bowel wall thickening (figures 14, 15). She refused surgery and received antibiotics. She returned one month later for the follow up. In the new scan a large left lateral abdominal wall abscess was evident (figure 16 on page 23). After drainage of the abscess and adequate treatment she underwent a third CT scan six months later showing marked improvement (figure 17 on page 24). Patient 8 Page 7 of 27

Female 34 years old, presented with progressive crampy pain extending from the left to the right lower abdomen, of six days duration, nausea, watery diarrhea and brown vaginal discharge. The physical examination was painful and the IUD was removed. On Ultrasound a heterogeneous lesion was found in the left adnexal region measuring 6X4 cm, while another solid lesion was noted within the first one measuring 3cm in diameter (figure 18 on page ). No flow was shown inside the lesion (figure 19 on page ). There was also an amount of free fluid in the pelvis (figure 20 on page ). Diverticulitis as well as a left ovarian lesion were considered in the differential diagnosis. Diagnostic laparoscopy was performed. Purulent ascites was found with pus pockets adjacent to the uterus and an enlarged left ovary. Biopsies were taken and drainage was performed. Cultures supported the diagnosis of actinomycosis. Patient 9 Female 44 years old, presented with pain in the left lower abdominal quadrant that existed for more than a month and she had no gynecological complaints. An IUD was in situ for 10 years. Gynecological US showed a mass in the left of the uterus. On a subsequent CT scan a solid and cystic mass was identified on the left pelvic area, while there was also involvement of the sigmoid colon and the pericolonic fat (figure 21 on page & figure 22 on page ). The infiltration was extended anteriorly towards the abdominal wall, where a small abscess was noted on the left (figure 23 on page ). There was also dilatation of the left ureter (figure 24 on page ). As the process appeared to arise from the colon, colonic cancer could not be excluded and sigmoidoscopy was performed, showing obstruction 25cm from the anus. Metastases in the left ovary were also discussed in the differential diagnosis. Diagnosis of actinomycosis was made after laparoscopy and biopsies. Images for this section: Page 8 of 27

Fig. 1: Figures 1-2: An inflammatory mass involving the right adnexa and the sigmoid region is seen. There is also extensive inflammatory infiltration of the pelvic fat anteriorly and some loops of small bowel are also involved. Page 9 of 27

Fig. 2: Figures 1-2: An inflammatory mass involving the right adnexa and the sigmoid region is seen. There is also extensive inflammatory infiltration of the pelvic fat anteriorly and some loops of small bowel are also involved. Page 10 of 27

Fig. 3: Figures 3-4: CT images after administration of rectal contrast: bowel compression is evident as well as thickening of the sigmoid colonic wall. Page 11 of 27

Fig. 4: Figures 3-4: CT images after administration of rectal contrast: bowel compression is evident as well as thickening of the sigmoid colonic wall. Page 12 of 27

Fig. 5: Figures 5-6: Many "cystic" lesions consistent with abscesses are seen in the pelvic area, involving the ureters and resulting in mild hydronephrosis. Same patient as in figures 3-4. Page 13 of 27

Fig. 6: Figures 5-6: Many "cystic" lesions consistent with abscesses are seen in the pelvic area, involving the ureters and resulting in mild hydronephrosis. Same patient as in figures 3-4. Page 14 of 27

Fig. 7: Figures 7-8-9: Many abscesses are evident on these CT images involving the pericecal and pelvic area, while there is also bowel wall thickening, inflammatory infiltration of the pelvic fat and extensive small bowel dilatation. Page 15 of 27

Fig. 8: Figures 7-8-9: Many abscesses are evident on these CT images involving the pericecal and pelvic area, while there is also bowel wall thickening, inflammatory infiltration of the pelvic fat and extensive small bowel dilatation. Page 16 of 27

Fig. 9: Figures 7-8-9: Many abscesses are evident on these CT images involving the pericecal and pelvic area, while there is also bowel wall thickening, inflammatory infiltration of the pelvic fat and extensive small bowel dilatation. Page 17 of 27

Fig. 10: CT image shows a very large abscess of the left lateral abdominal wall, as well as many intraabdominal smaller abscesses in the pelvic area above the uterus and the sigmoid colon. Page 18 of 27

Fig. 11: A mass-like heterogenous large lesion is shown in the right pelvis adjacent to a bowel segment that seems intact but slightly compressed. Page 19 of 27

Fig. 12: Abdominal CT image: many abscesses are evident in the right pelvis, while mild inflammatory fatty infiltration and small pelvic lymph nodes are noted. Page 20 of 27

Fig. 13: Thoracic CT image: a small abscess is seen in the right upper lobe and atelectasis in the left lower lobe associated with pleural effusion. Same patient as in figure 12. Page 21 of 27

Fig. 14: Figures 14-15: Many collections and abscesses are found in the pelvis and there is also inflammatory involvement of the fat and mild small bowel wall thickening. Page 22 of 27

Fig. 15: Figures 14-15: Many collections and abscesses are found in the pelvis and there is also inflammatory involvement of the fat and mild small bowel wall thickening. Page 23 of 27

Fig. 16: A large left lateral abdominal wall abscess is evident. Same patient as in figures 14-15 Page 24 of 27

Fig. 17: Marked improvement is seen concerning the inflammatory infiltration of the left lateral abdominal wall. Same patient as in figures 14-15-16. Page 25 of 27

Conclusion Abdominopelvic actinomycosis is not only related to long-term use of intrauterine contraceptive devices and should be included in the differential diagnosis when imaging shows concentric bowel wall thickening enhancing homogeneously, together with pelvic masses, abscesses and extensive inflammatory fat infiltration, specifically in cases or previous surgery, immunosuppression or chronic inflammatory disease. Abdominal actinomycosis should not be confused with malignancies, intestinal tuberculosis, chronic appendicitis, ameboma, diverticular disease, Crohn's disease, ulcerative colitis and tubo-ovarian abscess. Personal Information Aart J. van der Molen, M.D. A.J.van_der_Molen@lumc.nl A.C.G.M. van ES, M.D. a.c.g.m.van_es@lumc.nl Dept. of Radiology, C-2SLeiden University Medical Center Albinusdreef 2NL-2333 ZA Leiden The Netherlands M. Giannila, M.D. mgiannila@hotmail.com P. Maniatis, M.D. pekatman@otenet.gr C. Triantopoulou, M.D ctriantopoulou@gmail.com Dept. of Radiology, Konstantopouleio General Hospital 3-5, Agias Olgas street, 14233 N. Ionia Athens Greece Page 26 of 27

References 1. Marret H, Wagner N, Ouldamer L, Jacquet A, Body G. Pelvic actinomycosis: just think of it. Gynecol Obstet Fertil. 2010 May; 38(5):307-12. 2. Filipovi# B, Milini# N, Nikoli# G, Ranthelovi# T. Primary actinomycosis of the anterior abdominal wall: case report and review of the literature. J Gastroenterol Hepatol. 2005 Apr;20(4):517-20. 3. Lunca S, Bouras G, Romedea NS, Pertea M. Abdominal wall actinomycosis associated with prolonged use of an intrauterine device: a case report and review of the literature. Int Surg. 2005 Sep-Oct;90(4):236-40. 4. Nasu K, Matsumoto H, Yoshimatsu J, Miyakawa I. Ureteral and sigmoid obstruction caused by pelvic actinomycosis in an intrauterine contraceptive device user. Gynecol Obstet Invest. 2002;54(4):228-31. Page 27 of 27