Pulmonary malakoplakia secondary to Rhodococcus equi infection mimicking a lung neoplasm in a lung transplant recipient.

Pulmonary masses occasionally occur after lung transplantation and vary in etiology, which includes malignant and benign conditions, such as infection. Here, we report a case of a patient presenting with a lung mass 3 years after lung transplant. To our knowledge, this is the first described case of pulmonary malakoplakia due to Rhodococcus equi infection in an allograft post-lung transplantation. This case outlines the challenges of differentiating benign from malignant masses after transplantation.