Invasive Fungal Sinusitis: Comparison of Fine Needle Fungal Cytology and Middle Turbinate Biopsy Alone and in Combination as a Diagnostic Battery in Patients with Normal Nasal Endoscopy

Introduction: Acute invasive fungal sinusitis (AIFS) is easily diagnosable when frank mucosal changes of pallor or necrosis are evident on nasal endoscopy. However, these changes often occur late, and endoscopy is often normal in early stages of the disease. Imaging may be normal or often shows nonspecific unilateral sinus thickening. These patients are often missed, and due to the rapidly progressive nature of the disease, the resultant delay leads to loss of valuable time and worsened prognosis. Middle turbinate biopsies have earlier been proposed to improve the diagnostic yield in these patients. Others have showed Fine needle aspiration (FNA) as another possible diagnostic tool in AIFS.2 However, there has not been any studies comparing the two, and more importantly if combining the two can improve the diagnostic yield and accuracy. This is a prospective, national referral center based study to address this.

Materials and Methods: After obtaining due IRBs, patients with strong clinical suspicion of AIFS, who were normal on initial endoscopy were included in the study. Based on symptoms, or imaging, when available, they underwent unilateral middle turbinate biopsy (MTB) preceded by a standardized needle aspiration under endoscopic vision. Biopsy specimen was analyzed by frozen section and needle aspirate was stained with Giemsa, Hematoxylin-Eosin and periodic acid Schiff. Biopsy reports were standardized to whether fungal elements were seen in the tissue, and Hyphae seen or not on FNA. If either tool was positive, Amphotericin B was started tissue was obtained for permanent pathology, and fungal culture. Regular debridements and check endoscopies were done as per institutional protocol. In negative patients, check endoscopy was done at 48 hours, or if patient continued to worsen. All patients were followed up to 6 months or disease specific outcome

Results: A total of 27 patients out of 49 met the inclusion criteria upon endoscopy. Out of these, 11 patients went on to develop AIFS. 8 of these patients were positive on MTB, and 9 on FNA, out of these 7 patients were positive on both, yielding a sensitivity of 72.7% for MTB alone, 81.8% on FNA alone, and 90.9% for MTB + FNA. Both tests were 100% specific. Speciation showed 7 cases of aspergillosis, 3 cases of Rhizopus, and 1 case of Candida. Detailed statistical analysis was done. 1 patient had bleeding requiring cauterization.

Discussion and Conclusion: Combination of MTB and FNA improves sensitivity in early AIFS. Both tests are complimentary, and FNA alone was positive in two patients, both of who had significant anterior septal deviation, which may have made MTB difficult. Conversely MTB alone was the submucosa. To our knowledge, this is the first study of this nature.

Due to the rarity of the disease, sample size is small, and further studies are needed to validate our findings.