First reported case of phaeohyphomycotic bursitis due to Paraconiothyrium estuarinum.

A 51-year-old male presented with right knee swelling with persistent pain for the past two weeks. Radiograph of the knee showed no bone abnormalities. Bursectomy was performed and the aspirated fluid was sent for laboratory analysis. Gram staining revealed fungal filaments, and culture on Sabouraud's dextrose agar yielded blackish-brown pigmented fungal colonies. Histopathological examination showed slender, septate hyphae. PCR sequencing identified Paraconiothyrium estuarinum as the causative agent. The patient was treated with itraconazole for 3 months with regular follow-up, resulting in clinical improvement. This case highlights the diagnostic challenges and therapeutic considerations in managing fungal bursitis caused by Paraconiothyrium estuarinum.