Confirmatory diagnosis of invasive maxillary sinus aspergillosis by in situ hybridization: Report of two cases in immunocompetent subjects

Invasive maxillary sinus aspergillosis (IMSA) is uncommon in immunocompetent patients. The infection could become life-threatening due to delayed or mistaken diagnosis as it may extend into the orbit and brain. Two cases of invasive maxillary sinusitis caused by Aspergillus are described in apparently healthy subjects. Identification of the causative fungi as Aspergillus species was established by in situ hybridization of tissue samples, even though the culturing of tissue samples failed to isolate Aspergillus species. Surgical debridement of the infected sinus tissue and antifungal therapy with itraconazole resulted in a favorable outcome. For prompt and accurate diagnosis of IMSA, we highlight the usefulness of a new molecular diagnostic method, i.e., in situ hybridization in tissue samples.