Teaching Case

A 25-year-old woman presented at the emergency department with right lower quadrant abdominal pain lasting 24 hours, associated with nausea, vomiting and fever. She had no relevant medical history. Laboratory workup excluded pregnancy and documented elevated inflammatory parameters, namely leukocytosis with neutrophilia and elevated serum C-reactive protein.

Transvaginal ultrasound (TVUS) revealed the presence of a tubular complex lesion located on the right lower quadrant with internal echoes, fluid/fluid layering and incomplete, thick-wall and hypervascular septa (Figs. 1 and 2). The right ovary was partially visualised contiguous to the lesion and showed hypervascularisation (Fig. 3). A similar lesion was identified adjacent to the left ovary, which had normal dimension and morphology (Fig. 4). The patient referred tenderness at ultrasound (US) examination. The uterus evaluation was normal.
A contrast-enhanced computed tomography (CT) was also performed and showed bilateral serpiginous multilocular adnexal masses with internal fluid, thick-enhancing walls and internal septa. A small amount of free fluid on right lower quadrant and paracolic gutter and pelvic fat stranding were also noted (Fig. 5). Abnormalities of the gastrointestinal and urinary tract were ruled out. The patient was treated with intravenous antibiotherapy with clinical and laboratory improvement.

Pelvic inflammatory disease (PID) refers to a spectrum of acute sexually transmitted infections of the upper genital tract [1, 2]. It is a common cause of acute pelvic pain in reproductive-aged women [3], typically caused by Neisseria gonorrhoeae and Chlamydia trachomatis, although 30-40% of infections are polymicrobial [1-4].
PID is an ascending infection, usually beginning as cervicitis and extending upwards to the endometrium, the fallopian tubes and, if untreated, can ultimately cause a tubo-ovarian complex or abscess (TOA) [1, 3].
PID generally presents as acute pelvic pain, vaginal discharge, cervical motion tenderness, fever, and leukocytosis [1, 3, 4]. Patients may develop right upper quadrant pain due to intraperitoneal spread of infection along the paracolic gutters (perihepatitis or Fitz-Hugh-Curtis syndrome) [2, 4]. Imaging has a crucial role in doubtful cases and in the evaluation of disease extent [3, 4]. The modality of choice is TVUS with colour or power Doppler. CT is useful as a complementary and problem-solving modality, especially in cases of complications such as TOA or peritonitis, and for drainage guidance [2-4].
The imaging findings depend on disease severity, early and uncomplicated cases are typically subtle [1-3].
On US, endometritis manifests as endometrial heterogeneous thickening, increased vascularity and fluid or gas in the endometrial cavity [1, 3, 4]. Salpingitis is characterised by tube distension with fluid, wall thickening, incomplete septa with increased vascularity and oophoritis by ovarian enlargement with polycystic appearance and fluid with internal echoes. In pyosalpinx there is a thick-walled, tubular adnexal mass with low-level echoes or layering echogenic fluid with a “cogwheel” appearance. TOA are complex thick-walled, multilocular cystic adnexal collections, with internal echoes or fluid-fluid levels, hypervascular walls and septations. Usually TOA are bilateral with breakdown of adnexal architecture. In tubo-ovarian complexes some ovarian tissue is preserved [1, 3].
On CT, early findings include thickening of the uterosacral ligaments and pelvic fat haziness. Abnormal endometrial enhancement and endometrial fluid, enhancement and thickening of the fallopian tubes, and abnormal enhancement, enlargement, and reactive polycystic change of the ovaries indicate, respectively, endometritis, salpingitis and oophoritis. Pyosalpinx shows fluid-filled tubular tortuous lesions, with thick enhancing walls and interdigitating mural septa. TOA appears as a low-attenuation, multilocular, thick-walled adnexal mass with a serpiginous structure.
Without effective treatment, PID can lead to infertility, ectopic pregnancy, and chronic pelvic pain [2, 3].
PID is a common disease with nonspecific symptoms. Its early diagnosis, management and treatment are essential to avoid long-term complications such as infertility.