Rhinocerebral mucormycosis in immunocompetent patients: a case report and review of literature

Abstract

Introduction: Mucormycosis of the head and neck region is a rare but aggressive fungal infection that usually involves immunocompromised patients. More infrequently, this infection can also occur in people with no otherwise known underlying immunological deficit. This rarity usually causes a delay in diagnosis and may severely decrease the chance of survival in these patients. In this study, we present an extreme case of mucormycosis in an immunocompetent patient. By conducting a thorough review of the literature, we aim to increase our knowledge on this matter. Our goal is to improve diagnosis and start treatment at an earlier stage. Case presentation and methods: Our patient was a 31-year-old man who presented with bilateral face numbness, neck pain, headache, and a necrotic palatal lesion 45 days after a dental root canal procedure. There was extensive involvement of facial and skull base bony and soft tissues. Through two debridement sessions and intravenous antifungal treatment, the patient was discharged with near-complete disease resolution. We identified 48 cases in the literature that matched our study criteria. We searched the current literature for proven cases of mucormycosis in the head and neck region who didn’t have any underlying disease. We extracted their data and added the data of our patient. Then, we re-analyzed them using descriptive analysis, chi-square, and binary logistic regression to better understand the different factors for survival and disease burden in these patients. Results: 49 patients were analyzed in this study. The mean age was 46.93 ± 15.75 (min 16 and max78 years old). The most prevalent subsite to be involved was the sino-nasal mucosa, followed by the surrounding soft tissues and the orbit. While both orbit and intracranial tissue involvement differed significantly between surviving and deceased patients, only intracranial tissue involvement could be used to predict survival. The overall survival rate was 91.8%. Conclusion: Although very rare, mucormycosis can occur in immunocompetent patients. Physicians should consider mucormycosis when faced with refractory conditions and unusual symptoms such as exposed bones, facial numbness, headaches, and intractable pain. Complementary imaging (CT scan with or without MRI) and histopathological examination are critical for timely diagnosis or exclusion of this potentially fatal yet treatable disease.