P217 Pelvic mycoses— an unusual presentation of Rhizopus arrhizus in an ommunocompetent patient

POSTER SESSION 2, SEPTEMBER 22, 2022, 12:30 PM - 1:30 PM: INTRODUCTION: The rare but increasingly identified infections caused by Mucorales are always detrimental to the patient due to rapid vascular invasion and the need for thorough surgical debridement and definitive antifungal therapy for its cure. Among the Mucorales, maximum cases have been reported among Mucor spp. and Rhizopus spp. Case: Here we present a case of a 9-year-old immunocompetent child presenting with abdominal pain and distension of 1-month duration followed by swelling of bilateral lower limbs, which was gradual in onset. Ultrasonography of the abdomen and pelvis was done which revealed a pelvic mass on the left side. The child developed acute urinary retention during the hospital stay, which was evaluated to reveal a fistulous connection between urethra and rectum for which transverse colostomy was done. The USG-guided biopsy of the left pelvic mass showed broad aseptate hyphae in Hematoxylin and Eosine staining whereas the KOH mount and culture were negative. The follow-up imaging with CT showed circumferential thickening of the recto-sigmoid region and involvement of the posterior bladder wall. Considering the rapidity of the spread of the infection, injection liposomal Amphotericin B at the dose of 5 mg/kg/d, i.v. was started and given for one week with minimal improvement. However, with this clinical picture and patient profile the diagnosis was strongly suspected to be of Basidiobolomycosis of rectosigmoid region. Treatment also was revised to injection of voriconazole at a dose 8 mg/kg/d, i.v. after loading dose which was later shifted to oral dose after 7 days. A repeat USG-guided biopsy was planned for gene sequencing, which identified the organism as Rhizopus arrhizus. On follow-up, patient showed no clinico-radiological improvement and in view of the mycological evidence, the anti-fungal was changed from voriconazole after 2 weeks to oral isavuconazole at the dose of 200 mg/d following the loading after which significant improvement was achieved and patient was discharged. CONCLUSION: Mold infection in the form of spreading rectosigmoid mass in an immunocompetent child usually suggests the picture of Basidiobolomycosis. Treating patients only on clinical grounds without mycological confirmation may lead to overlooking of Mucormycosis and may result in adverse outcomes. The diagnosis of Mucormycosis should always be considered as a differential for a fungal infection in the form of mass lesion in abdomen.