Tubo-ovarian abscess is a complex infectious mass of the adnexa, which is formed as a consequence of pelvic inflammatory disease. Classically, tubo-ovarian abscess presents with an adnexal mass, fever, elevated white blood cell count, lower abdominal-pelvic pain, and/or vaginal discharge. However, the clinical picture of this disease can vary significantly. If the abscess ruptures, life-threatening sepsis can occur, so any suspicion of this diagnosis requires prompt evaluation and treatment. The majority of patients are women of reproductive age who are sexually active. Most often, these abscesses occur as a late complication of pelvic inflammatory disease. Pathogens from a cervical or vaginal infection first reach the endometrium and then pass through the fallopian tubes into the peritoneal cavity, where they form a walled mass. The majority of cases are associated with peritonitis. Finally, tubo-ovarian abscess may arise from an adjacent infected organ, most commonly the appendix, less commonly by hematogenous spread from a distant site of infection or as an association with pelvic cancer. Risk factors for tubo-ovarian abscess are similar to those for pelvic inflammatory disease and include reproductive age, IUD placement, multiple sexual partners, and a history of a previous episode of pelvic inflammatory disease. The differential diagnosis often includes appendicitis, diverticulitis, inflammatory bowel disease, IUD infection, ovarian torsion, ectopic pregnancy, ruptured ovarian cyst, pyelonephritis, or cystitis. These abscesses most often occur in women of reproductive age after an upper genital tract infection. However, tubo-ovarian abscess can also occur without a previous episode of pelvic inflammatory disease or sexual activity and can sometimes develop as a complication of hysterectomy. It should be noted that women who are HIV positive and have diagnosed pelvic inflammatory disease usually have a slower clinical resolution of the disease and therefore an increased risk of developing a tubo-ovarian abscess. Bacteria from the lower genital tract ascend to form an inflammatory mass involving the fallopian tube, ovaries, and potentially other adjacent pelvic organs. Tubo-ovarian abscesses are often polymicrobial and usually contain a predominance of anaerobic bacteria. The classic presentation of the disease includes abdominal pain, a pelvic mass on examination, fever, and leukocytosis. However, two researchers found that 35% of women with tubo-ovarian abscess were afebrile, and 23% of those affected had normal white blood cell counts. A complete physical examination should be performed, including a thorough pelvic examination. A speculum and bimanual examination should assess the consistency, size, and mobility of the uterus and both fallopian tubes. References: 1. Tao X,Ge SQ, Chen L, Cai LS, Hwang MF, Wang CL. Relationships between female infertility and female genital infections and pelvic inflammatory disease: a population-based nested controlled study. Clinics (Sao Paulo). 2. Fouks Y, Cohen A, Shapira U, Solomon N, Almog B, Levin I. Surgical Intervention in Patients with Tubo-Ovarian Abscess: Clinical Predictors and a Simple Risk Score. J Minim Invasive Gynecol. 3. Fouks Y, Cohen Y, Tulandi T, Meiri A, Levin I, Almog B, Cohen A. Complicated Clinical Course and Poor Reproductive Outcomes of Women with Tubo-Ovarian Abscess after Fertility Treatments. J Minim Invasive Gynecol. PubMed 4. Inal ZO, Inal HA, Gorkem U. Experience of Tubo-Ovarian Abscess: A Retrospective Clinical Analysis of 318 Patients in a Single Tertiary Center in Middle Turkey. Surg Infect (Larchmt).