Spontaneous resolution of rhodococcal pulmonary infection in a liver transplant recipient

Pulmonary infection by Rhodococcus equi is characterized by indolent infection in an immunocompromised host with a propensity to form cavitary lesions. Mortality can be greater than 50%; treatment involves prolonged therapy with multiple antibiotics and, occasionally, surgical resection. Recurrence is common. We report a case of a liver transplant patient with a pulmonary nodule caused by R equi; the nodule followed a benign clinical course and resolved spontaneously. This case illustrates that the spectrum of disease caused by R equi is not fully appreciated and that significant pitfalls complicate the diagnosis and management of infection by this unusual and probably underrecognized pathogen.