Genitourinary Tract Tumors in Children: An Update

Background: Genitourinary tract tumors in children are less common than in adults. Most of these tumors have different genetic backgrounds, clinical presentation, and oncologic behavior than their adult counterpart. As a result of low prevalence in children, some of the treatment approaches and recommendations are based on treatment experience in adult patients. However, thanks to scientific and technological development, survival rates have risen considerably. Objective: This paper presents a review of the principal features of the tumors involving the genitourinary tract in children and an update in genetic background, diagnosis, and treatment. Methods: A narrative review was performed on published literature about genitourinary tract tumors in pediatric patients. Papers presented in English and Spanish literature were reviewed. PubMed, Science Direct, and SciELO databases were used to collect information and present this article. Results: Kidney tumors are the most common type of genitourinary tumors in children. Among those, Wilms tumor represents the majority of cases and shows the successful work of clinical trial groups studying this tumor type. Other tumors involving the genitourinary tract in children include Rhabdomyosarcoma, Transitional cell carcinoma, Testicular, and Adrenal tumors. Conclusion: Genitourinary tract tumors in children represent significant morbidity and economic burden, so awareness in early diagnosis represents improvement in treatment, clinical and oncological outcomes.

A RARE COMPLICATION OF A COMMON DISEASE?

The iliopsoas muscle abscess is rare condition, with increasing recognition, that can be either primary, by hematological or lymphatic dissemination, or secondary to infections in the gastrointestinal, genitourinary tract or musculoskeletal system. Its early identification is highlighted, for an adequate therapeutic orientation, contributing to a good prognosis.

598. A 3-Year Evaluation of Antibiotic Resistance Patterns in Gram-Negative Genitourinary Tract Infections Treated in Outpatient Infusion Centers (POICs)

Background Resistant Gram-negative pathogens (GNP) are common causes of genitourinary tract infections (GUI) often requiring outpatient parenteral antibiotic therapy (OPAT). Data are sparse regarding antibiotic resistance of GNP in patients (pts) treated with OPAT. We analyzed GNP of GUI pts treated in Infectious Disease OICs over a 3-year period stratified by location prior to OPAT. Methods Records from 18 POICs were queried for GUI pts with ≥1 GNP receiving OPAT from 2018 to 2020. Demographics, pt location prior to OPAT, infection type, year of therapy, and GNP were recorded. Antibiotic resistance patterns were defined as extended-spectrum beta-lactamase (ESBL) or multi-drug resistant (MDR). Chi Square and Fisher’s exact test were used to determine if ESBL status was associated with GNP or location prior to OPAT (hospital vs. community). The Cochran-Armitage test was used to analyze temporal trend in ESBL expression. Statistical significance was defined as P< 0.05 for all tests. Results A total of 634 GNP were identified in 601 pts (mean age: 64±16, 58% female). Infections were 75% complicated urinary tract infection, 20% pyelonephritis, and 5% prostatitis/other. Overall, 56% (n=339) were treated directly from the community and 44% (n=262) following hospital discharge. GNP isolated were 56% E. coli, 19% Pseudomonas spp., 16% Klebsiella spp. and 9% others. Of the 611 GNP with potential to express ESBL, 43% (n=265) were ESBL producers (Table 1). Significantly more ESBL-producing GNP occurred in pts discharged from a hospital prior to OPAT compared to the community (53% vs. 36%, P< 0.001). Overall, the incidence of MDR constituted 36% (n=231) of GNP, which did not differ by location prior to OPAT. Evaluation of ESBL incidence by year showed a significant increase from 2018 to 2020 (P=0.03). Although a slight increase in MDR was noted from 2018 to 2020, this was not significant (Figure 1). Table 1. Frequency of ESBL and MDR by Location prior to OPAT Figure 2. Prevalence of ESBL producers and MDR Pathogens by Year Conclusion Resistant GNP were observed in the OPAT setting for GUI with both ESBL and MDR pathogens. We saw a significantly higher rate of ESBL with GNP from hospital discharged pts compared to community-acquired infections and an increase in the overall incidence of ESBL over time. Management of Gram-negative genitourinary infections in the OPAT setting requires close monitoring of emerging resistance patterns. Disclosures Kimberly A. Couch, PharmD, MA, FIDSA, FASHP, AbbVie (Speaker's Bureau) Lucinda J. Van Anglen, PharmD, Merck & Co. (Research Grant or Support)

203. Gardnerella vaginalis Bacteremia in Male Patients: A Case Series and Review of the Literature

Background Introduction: Gardnerella vaginalis is a colonizer of the female genitourinary tract and can cause serious morbidity as a pathogen. It is an uncommon cause of infection in men and bacteremia with this organism is rare. We describe two cases of G. vaginalis bacteremia in male patients. A literature search was performed for cases of G. vaginalis bacteremia in men. A total of 13 patients were identified and discussed. Methods Case 1: A 52-year-old man with diabetes and prior nephrolithiasis presented for dysuria, hematuria, and left sided flank pain. He was febrile and tachycardic with mild left costovertebral angle tenderness, leukocytosis and acute kidney injury. Urinalysis revealed pyuria. Computed tomography of the abdomen and pelvis showed pyelonephritis and a small calculus of the proximal left ureter. He was treated with ceftriaxone and then piperacillin-tazobactam. Aerobic culture of the urine yielded < 10,000 cfu/mL of mixed gram-positive flora. Blood cultures yielded G. vaginalis after 48 hours. He was treated with ciprofloxacin 500 mg orally twice daily for 7 total days and clinically recovered. Case 2: A 61-year-old man with alcohol use disorder and gout, presented with altered mental status. He had leukocytosis and acute kidney injury and was treated with vancomycin and cefepime with clinical improvement. Admission blood cultures demonstrated G. vaginalis in the anaerobic bottle of 1 of 2 cultures, reported 96 hours after collection. Urine culture was negative. The patient was treated with amoxicillin-clavulanate on discharge to complete a 14-day course with clinical resolution. Results see above Gram stain of G. vaginalis on blood culture Conclusion Discussion: G. vaginalis is a facultative anaerobic gram-positive pleomorphic rod, which can be gram variable due to poor staining of the thin peptidoglycan cell wall. Isolation and identification are often delayed. Bacteremia in men is rare but nearly all have originated in the genitourinary tract. The most severe cases of G. vaginalis bacteremia implicate endocarditis, urethral stricture and an empyema as the sources. Collection of blood cultures and speciation are often delayed, ranging from 48 hours to 7 days. Selection and duration of treatment have ranged widely in previously reported cases, likely due to the lack of guidance regarding effective treatment. Disclosures Andrew Chou, MD, bluebird bio (Shareholder)