Nodulisporium Fungal Brain Abscess In Early Post-Renal Transplant: A Rare, Unexpected, Mysterious Pathogen

BACKGROUND Central nervous system fungal infections are rarely encountered in current medicine, with fungal abscesses even less commonly seen. Clinical entities and their development largely depend on the interplay between the host's immune system and fungal virulence factors. Due to the large size of fungal organisms, they are prevented from entering the meningeal circulation. Hence, they cause focal diseases like cerebritis, abscesses, vasculitis of larger vessels, vascular occlusion, cerebral infarcts, and aneurysms. CASE REPORT A 34-year-old male patient of Indian descent diagnosed with stage 5 chronic kidney disease, bilaterally small kidneys, and hypertension underwent cadaveric renal transplantation and subsequent immunosuppression. Three months later, he returned with complaints of high-grade fever with chills and rigor, along with massive headaches. Plain brain computed tomography showed an intra-axial heterogeneously hypodense area with a hyperdense rim in the right temporal lobe. MRI revealed a well-defined enhancing lesion with irregular crenated margins and satellite lesions. Abscess wall biopsy showed fragments of hyaline septate filamentous fungal hyphae. Craniotomy with excision and drainage of the abscess was done and sent for histopathological examination along with culture. The results showed the growth of Nodulisporium fungus. The patient was then managed on amphotericin B and voriconazole for completion of treatment. CONCLUSIONS This is the first case reported of a Nodulisporium species fungal abscess developing in the brain after cadaveric kidney transplantation. Urgent evaluation via imaging and biopsy is crucial in determining the exact causal organism of brain abscesses, which can lead to better patient outcomes.