An unusual cause for rib osteomyelitis in the tropics: Cryptococcal osteomyelitis

The more common manifestations of cryptococcal infections are restricted to the central nervous system and lungs. We report an unusual case of fungal osteomyelitis due to Cryptococcus. The patient was a young man who had been adequately treated for pulmonary tuberculosis three years prior. Three months before, he sustained a minor road-traffic accident with only minor abrasions. He presented with subacute chest pain of 15 days' duration and was found to have radiological evidence of a lytic lesion of the fifth rib. Given prior tuberculosis, he was thought to have a relapse of disease with tuberculous osteomyelitis. Surprisingly, a biopsy revealed evidence of fungal osteomyelitis with Cryptococcus. An evaluation for primary immunodeficiency revealed low CD4 cell counts with undetectable serum IgA and IgM levels. Genetic sequencing proved a genetic mutation consistent with primary T-cell immunodeficiency. The patient responded well to treatment and is asymptomatic on follow-up.