Cryptococcus Neoformans Osteomyelitis of the Right Ankle Diagnosed by Metagenomic Next-Generation Sequencing in a HIV-Negative Patient with Tuberculous Lymphadenitis and Pulmonary Tuberculosis: A Case Report and Recent Literature Review

Aim: Cryptococcus neoformans osteomyelitis coupled with tuberculosis and tuberculous lymphadenitis, is a rare occurrence in clinical. Diagnostic challenges arise due to the clinical radiological similarity of this condition to other lung infections and the limited and sensitive nature of traditional approaches. Here, we present a case of co-infection diagnosed using Metagenomic Next-Generation Sequencing, highlighting the effectiveness of advanced genomic techniques in such complex scenarios.
Case Presentation: We present a case of a 67-year-old female infected with cryptococcal osteomyelitis and presented with swelling and pain in the right ankle. Following a biopsy of the right ankle joint, Metagenomic Next-Generation Sequencing (mNGS) of the biopsy tissue revealed Cryptococcus neoformans infection. Positive results for Cryptococcus capsular antigen and pathological findings confirmed the presence of Cryptococcus neoformans. The patient underwent surgical debridement, coupled with oral fluconazole treatment (300mg/day), leading to the resolution of symptoms.
Conclusion: Cryptococcus neoformans is an uncommon cause of ankle infection. Metagenomic Next-Generation Sequencing (mNGS) serves as a valuable diagnostic tool, aiding clinicians in differentiating cryptococcal osteomyelitis from other atypical infections.

Keywords: Cryptococcus neoformans, tuberculosis, diagnosis, metagenomic next-generation sequencing, mNGS