Pelvic actinomycosis: A hidden threat mimicking pelvic tumors.

A 44-year-old patient with no prior medical history, using an intrauterine device (IUD) for 10 years without monitoring, presented to the gynecological emergency department. she reported intermittent pelvic pain, yellowish vaginal discharge, and burning urination. These symptoms occurred alongside fever and a 5 kg weight loss. Upon examination, the patient had a fever of 38.5°C and exhibited pelvic tenderness. A pelvic ultrasound was performed, revealing a heterogeneous hypoechoic right tubo-ovarian complex ( Fig. 1 ) . Fig. 1 A pelvic ultrasound revealing a heterogeneous hypoechoic right tubo-ovarian complex. Fig 1: A pelvic ultrasound revealing a heterogeneous hypoechoic right tubo-ovarian complex. The patient exhibited leukocytosis (15,300 cells/mm3), (Normal range: 1700-7000 cells/mm3) and a C-reactive protein level of 60 mg/ml (Normal range:<5mg/ml). The patient underwent a pelvic MRI which revealed a tubo-ovarian complex, roughly oval in shape, fairly well-defined, with heterogeneous T1 hypointensity, heterogeneous T2 hyperintensity, restricted diffusion, and peripheral enhancement following Gadolinium injection, measuring 96 mm in height ( Fig. 2 ). The intrauterine device is in place ( Fig. 3 ) . Fig. 2 Pelvic MRI (A: Axial sequence, B: Coronal sequence, C: Axial sequence after Gadolinium injection) revealed a tubo-ovarian complex with heterogeneous T2 hyperintensity, enhanced at the periphery after Gadolinium injection. Fig 2: Fig. 3 Pelvic MRI showing the position of the intrauterine device (IUD). Fig 3: Pelvic MRI (A: Axial sequence, B: Coronal sequence, C: Axial sequence after Gadolinium injection) revealed a tubo-ovarian complex with heterogeneous T2 hyperintensity, enhanced at the periphery after Gadolinium injection. Pelvic MRI showing the position of the intrauterine device (IUD). Given the general health deterioration, the presence of a tubo-ovarian complex on the MRI, and especially the presence of a neglected IUD for 10 years, the diagnosis of pelvic actinomycosis was initially considered, but a neoplastic origin could not be entirely ruled out from the start. Serum tumor markers were negative, with ACE at 0.8 µg/L (normal range <2.5 µg/L) and CA125 at 20 µg/L (normal range <35 µg/L). The IUD was removed, and both vaginal swab and urinalysis were negative Given the high likelihood of an actinomycosis diagnosis, the surgeons and gynecologists decided, before surgical intervention, to initiate medical treatment and perform a pelvic MRI after 1 month to monitor the progress. The patient was hospitalized; she had a penicillin allergy and therefore received a daily intravenous administration of 200 mg of Vibramycin for 1 month. After 1 month of treatment, there was marked improvement in the patient's overall condition (no pain, no fever, with a significant weight gain), correction of the laboratory findings (CRP 35mg/ml vs. 134mgmg/ml, leukocytes: 8900 cells/mm3 vs. 16000 cells/mm3), and tumor markers remained within the normal range). Even the MRI showed a clear reduction in the right tubo-ovarian complex, measuring 42mm in height. ( Fig. 4 ) . Fig. 4 MRI showed a significant regression of the tubo-ovarian complex. Fig 4: MRI showed a significant regression of the tubo-ovarian complex. Despite this significant improvement, the gynecologists proposed a surgical intervention to confirm the diagnosis, but the patient, given her clinical improvement, refused to undergo surgery. Therefore, a medical treatment with Vibramycin 200mg/day for 6 months was prescribed, with monthly check-ups initially to assess progress.

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Pelvic actinomycosis should always be considered in women with long-term IUD use presenting with atypical pelvic masses or inflammatory findings. Accurate diagnosis is crucial to avoid unnecessary surgical intervention and ensure appropriate antimicrobial treatment.

Pelvic actinomycosis is a rare, chronic, suppurative, and granulomatous infection caused by Actinomyces, which are Gram-positive anaerobic bacteria [ 1 ]. The pelvic localization of actinomycosis is extremely rare, accounting for only 5% of all actinomycosis cases [ 2 ]. Its incidence is on the rise, primarily due to the frequent use of IUDs. In fact, Actinomyces is identified in 2 to 12% of women using IUDs for more than 2 years, especially those containing copper [ 3 ]. The long-term stimulating effect of the IUD on the mucous membrane leads to local endometrial lesions, inadequate blood supply, and disruption of the intrauterine microbiota, which provides the necessary conditions for the growth and spread of Actinomyces [ 5 ]. Some patients have developed pelvic actinomycosis even 10 years after IUD removal [ 6 ]. The bacterium can be more aggressive and invade neighboring organs by contiguity [ 4 ]. The clinical presentation is polymorphic and nonspecific, most commonly characterized by abdominal or pelvic pain, vaginal discharge, and weight loss [ 7 ]. The disease's course is chronic with a slow onset, but some patients experience severe complications such as septic shock, uterine perforation, intestinal perforation, or acute peritonitis. However, these clinical manifestations are not specific [ 8 ]. A biological inflammatory syndrome is often observed, with anemia found in 70% of cases, and some patients may have a slightly elevated CA125 level [ 1 ]. Imaging does not show specific signs. When pelvic actinomycosis occurs, it usually causes endometritis, salpingo-ovaritis, or tubo-ovarian abscess, and a mass in the adnexa may be palpable, suggesting a pelvic malignancy [ 9 ]. Pelvic actinomycosis presents clinical manifestations of severe invasive lesions, which are often mistakenly diagnosed as malignant tumors and are challenging to diagnose preoperatively. The diagnosis of actinomycosis may be suspected in any woman using a long-term IUD, given the combination of an inflammatory syndrome and a pelvic tumor syndrome. Preoperative diagnosis could be bacteriological. However, bacteriological diagnosis is challenging due to the sensitivity of Actinomyces to oxygen, the difficulty in culturing it, and its frequent association with other anaerobic organisms [ 10 ]. It has been reported that the rate of preoperative diagnosis is less than 10% [ 11 ]. Only the histopathological examination of a biopsy or surgical specimen confirms the diagnosis specifically by showing the presence of abscesses composed of altered neutrophilic polymorphonuclear cells surrounded by a histiolymphoplasmacytic infiltrate and a peripheral fibroblastic rim. These areas of suppuration are centered around a characteristic histological image known as a "sulfur granule." From the center of these grains, short, nonseptate filaments radiate outward and are positive in PAS and Grocott stains [ 10 ]. Differential diagnosis includes chronic inflammations, particularly tuberculosis and endometriosis, as well as malignant tumors, primarily ovarian [ 12 ]. Once pelvic actinomycosis is diagnosed, if an IUD is present, it should be removed, and penicillin therapy should be initiated. It is recommended to administer penicillin intravenously at a dose of 18 to 24 million units per day for 2 to 6 weeks, followed by oral administration of 2 to 4 grams per day for 6 to 12 months [ 13 ]. Due to the effectiveness of antibiotic treatment, surgical intervention is limited to excising necrotic tissue or draining abscesses [ 13 ]. Tetracycline, clindamycin, and erythromycin can be used in case of penicillin allergy [ 7 ]. In the case of our patient the therapeutic protocol was adapted by the use of Doxycycline due to her allergy to penicillin. The prognosis depends on the timeliness of treatment. Actinomycosis, in general, has a good prognosis when treated promptly. However, serious complications due to local spread or systemic involvement with distant organ damage have been reported, warranting extended monitoring [ 14 ]. Hence, Anthony et al. emphasize the importance of performing cervicovaginal smears in women at risk who use IUDs, which allows for the diagnosis of actinomycosis at an early stage in approximately 7% of cases [ 6 ]., In these cases, treatment is simpler, and outcomes are better.

Pelvic actinomycosis is a rare, chronic, suppurative, and granulomatous infection caused by the Gram-positive anaerobic bacterium Actinomyces israelii [ 1 ]. The pelvic form of this infection is extremely uncommon [ 2 ], but is often linked to long-term use of intrauterine devices (IUDs) [ 3 ]. Due to its nonspecific clinical and radiological presentation, distinguishing pelvic actinomycosis from ovarian neoplasms can be quite challenging. The first-line treatment primarily consists of prolonged antibiotic therapy, although surgical intervention may be necessary in some cases to address complications or remove affected tissues [ 4 ]. This highlights the importance of awareness and careful evaluation in patients presenting with pelvic symptoms, especially those with a history of IUD usage. Early diagnosis and appropriate management are crucial for effective treatment and improved patient outcomes. The main purpose of our study is to emphasize the importance of considering this often overlooked infection in any woman using a long-term intrauterine device (IUD), especially when it is associated with a pseudo-tumoral appearance on imaging. If the diagnosis is missed, the patient may undergo inappropriate and potentially debilitating surgery due to the diffuse and infiltrating nature of the infection.