First clinical isolation of Purpureocillium lilacinum in a pediatric oncological patient in Ecuador.

BACKGROUND: Purpureocillium lilacinum is a ubiquitous environmental fungus widely utilized as an agricultural biocontrol agent, but it is increasingly recognized as an opportunistic human pathogen. While invasive fungal infections caused by this microorganism have been documented globally, disseminated systemic presentations in pediatric oncology remain exceptionally rare and carry high mortality rates. CASE DESCRIPTION: We report the case of an 11-year-old female patient with a high-grade osteosarcoma who developed high-risk febrile leukopenia during chemotherapy. Blood cultures from both a subcutaneous port and peripheral blood turned positive for both yeast-like and hyphal structures, which were further identified by DNA barcoding (ITS and EF1a regions) as P. lilacinum. The patient exhibited concurrent multiorgan dissemination, including hyperchromic scaling skin lesions in the perianal region and limbs, as well as diffuse bilateral pulmonary micronodules confirmed via video-thoracoscopy biopsy. Despite initial treatment with amphotericin B and fluconazole, clinical resolution was successfully achieved only after optimizing the antifungal regimen with oral voriconazole. The patient fully recovered and remains stable. CONCLUSIONS: To our knowledge, this represents the first clinical isolation and reported case of disseminated systemic P. lilacinum infection in a pediatric oncological patient in Ecuador. This case highlights the aggressive nature of this pathogen in immunosuppressed children, the challenge of its diagnosis due to the lack of specialized infrastructure for antifungal susceptibility testing, and the critical importance of a multidisciplinary approach and prompt, targeted first-line therapy with voriconazole to ensure survival.