Transformation of a maxillary paranasal sinus fungal ball into a mass-like form of invasive fungal sinusitis in the immunocompromised host

Background Paranasal sinus fungal balls are typically non-invasive and can be managed conservatively in the immunocompetent. In the immunocompromised, life-threatening invasive transformation is possible. The temporal relationship between onset of fungal balls and invasive transformation is poorly understood. We report a patient with lymphoma undergoing chemotherapy, with multiple surveillance scans demonstrating evolution from non-invasive to invasive fungal disease. Results A 67-year-old male with multiply relapsed angioimmunoblastic T-cell lymphoma received multiple regimens of systemic chemotherapy over 2 years. During the latest course of romidepsin-azacitidine, he developed right frontotemporal headaches, right V2 numbness, and vertical diplopia. Cross-sectional imaging revealed an erosive soft tissue mass along the right orbital floor and inferior rectus without necrosis, and contiguous hyperdense material within the right maxillary sinus, suggesting superimposed fungal colonisation. Our suspicions were of lymphoma progression, or a second primary neoplasm. Histopathology from intralesional biopsies revealed Aspergillus with tissue invasion without angioinvasion. Retrospective review of multiple surveillance scans performed up to 1 month prior demonstrated presence of a right maxillary sinus fungal ball. He was treated for invasive fungal sinusitis with voriconazole and debridement. He remains well on prophylactic oral voriconazole while on chemotherapy. Conclusions Our report describes the timeline of invasive transformation of a paranasal sinus fungal ball in an immunocompromised host. Further studies are needed to understand its chronology. Invasive disease can also appear mass-like without clinically apparent necrosis, mimicking neoplasms. Due to its high mortality, vigilance and surgical removal is strongly advised in patients with paranasal sinus fungal balls planned for immunosuppression, and even immunocompetent or diabetic patients.