Musculoskeletal imaging in disseminated fusariosis: A case report with diagnostic imaging challenges

Disseminated fusariosis is a life-threatening opportunistic fungal infection that primarily affects immunocompromised patients with hematologic malignancies. Its imaging manifestations are heterogeneous and may evolve during immune recovery, complicating the distinction between active infection and inflammatory response. We report the case of a 31-year-old man with acute myeloid leukemia who developed disseminated Fusarium solani infection involving the skin, soft tissues, paranasal sinuses and bones during induction chemotherapy. Contrast-enhanced computed tomography, ultrasound, magnetic resonance imaging and 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT), demonstrated lesion evolution after neutrophil recovery, including a characteristic ultrasound target sign and corresponding peripheral enhancement and FDG uptake despite clinical improvement. Histopathology and follow-up biopsies supported immune reconstitution inflammatory syndrome rather than persistent fungal infection. This case highlights the importance of interpreting imaging findings with clinical and pathological data during immune recovery. Recognition of imaging changes associated with immune reconstitution inflammatory syndrome may help avoid misdiagnosing inflammatory lesions as persistent or progressive fungal infection.