Invasive Fungal Sinusitis: Clinical Pathologic Characteristics of Acute vs. Chronic Infections

Introduction/Objective Invasive fungal sinusitis is a serious condition requiring early diagnosis and treatment. It has been classified into acute, chronic and granulomatous forms. This study aims to investigate clinical pathologic aspects such as a) Frequency of mass forming lesions, b) Frequency of granulomatous reaction, c) Frequency of acute inflammatory reaction and d) Frequency of angioinvasion, perineural invasion and necrosis, to determine if these factors allow a more meaningful clinical-pathologic classification. Methods/Case Report Cases of invasive fungal sinusitis with surgical pathology specimens available in our laboratory since January 1, 2006 to date were gathered. Electronic medical records, histopathologic diagnostic material and laboratory fungal identification results were reviewed. Results (if a Case Study enter NA) Thirty-one cases of invasive fungal sinusitis were found: Twenty-two were acute (< 4wk duration) and 9 chronic. Patient comorbidities in acute cases were malignancies: 45%, diabetes mellitus: 26% and solid organ transplant: 10%. Among patients with malignancies, 5 cases had relapsed/refractory acute myeloid leukemia with neutropenia < 1000/uL. Patients with diabetes mellitus exhibited an average HbA1c of 10.0%. Two out of 3 transplant patients had graft versus host disease. The most common causative fungi were species of Aspergillus, Candida and mucormycetes. By contrast, a third of the chronic cases had a history of recreational drug use and six presented with space occupying lesions seen on imaging studies. Upon histologic review, four of these showed granulomas and the majority of cases exhibited extensive necrosis. Among necrotic cases, perineural and vascular invasion by fungal organisms was identified. Conclusion We report the contrasting clinical pathologic characteristics of acute and chronic invasive fungal sinusitis in a series of cases treated at University affiliated tertiary/quaternary-care Hospitals. Acute invasive sinusitis is usually a complication of severe systemic diseases. Chronic cases are caused by various medical conditions including the use of recreational drug and may mimic neoplasms on imaging.