Aspergillus Osteomyelitis of the Ribs in Immunocompetent Hosts: Report of Two Rare Cases

Introduction Osteomyelitis is rarely caused by fungi, most common among them being Candida. Aspergillus is a rare cause of fungal osteomyelitis mimics tuberculous osteomyelitis. Aspergillus osteomyelitis (AO) of the ribs is relatively uncommon, with an incidence rate of only 9% among all reported cases of AO. With mortality rates of almost 25%, AO is on the rise attributed to increasing numbers of immunocompromised individuals. There are very few case reports of AO of ribs in immunocompetent individuals. We report two such cases. Case Report Case 1: A 51-year-old male developed spontaneous chest pain along right costal margin with a low-grade fever. High-resolution computed tomography chest revealed osteomyelitis of anterolateral chest wall. He did not improve with empirical antitubercular therapy, and subsequent debridement showed polymicrobial pyogenic infection which was managed with appropriate antibiotics elsewhere. Samples were not sent for fungal culture. He presented to us 3 months later, and surgical debridement showed growth of Aspergillus flavus which was managed with oral voriconazole. The lesion healed with no recurrence at 24-month follow-up. Case 2: A 40-year-old male presented to our institute with left-sided chest pain, low-grade fever, and loss of appetite. There was a history of injury with a sharp piece of wood 2 years earlier. Magnetic resonance imaging defined the lesion which was biopsied under ultrasound guidance. Cultures grew A. flavus which was treated with oral voriconazole. He had complete clinical improvement at 16-month follow-up. Conclusion More number of AO cases are being reported in immunocompetent individuals. Variability in clinical picture, rarity, misdiagnosis, empirical therapy, and failure to send deep tissue samples for fungal cultures are some of the reasons for the high mortality rates. It is paramount in today's scenario of atypical presentations, to obtain deep tissue for all cultures including fungal culture and histopathology, either surgically or under image guidance to achieve good clinical outcomes. Our study highlights that following the strict protocol of obtaining tissue for fungal culture, systemic antifungal therapy, and surgical debridement where necessary can help to diagnose and treat this rare pathology and ensure the good clinical outcome.