Bone Erosion in Allergic Fungal Sinusitis

Abstract

Allergic fungal (Aspergillus) sinusitis was initially described in 1983. Histologic identification of fungal hyphae, eosinophils, and Charcot-Leyden crystals in allergic mucin from the involved sinus is considered diagnostic. The fungus is felt to incite the allergic response. The histologic similarity of this disease to allergic bronchopulmonary aspergillosis prompted the name, allergic aspergillus sinusitis. However, in the absence of definitive cultures or laboratory tests indicating Aspergillus as the organism involved, the more appropriate term would be allergic fungal sinusitis. Bone erosion frequently has been described in invasive fungal sinusitis, especially in immunocompromised hosts. However, bone erosion has been seen in only 4 of 21 previously reported cases of allergic fungal sinusitis and is considered unusual. We report 11 additional cases diagnosed over the last 52 months. Seven were noted on computed tomographic scan to have marked multifocal bone destruction. Histologically, this appears to be caused by bone resorption and remodeling rather than tissue invasion by fungal organisms.