Nocardia brain abscess in a 49-year-old woman with pulmonary alveolar proteinosis: a case report

Abstract

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disease, associated with functional impairment or reduced decrease in the number of alveolar macrophages. Primary or autoimmune type is the most common. The impaired function of immune system made these patients susceptible to opportunistic infections like nocardiosis. A 49-year-old Iranian previous healthy woman was admitted with seizures and a history of one-month respiratory symptoms prior to the seizure attack which was treated as pneumonia. Chest CT and brain MRI were performed, which revealed ‘honey-comb’ pattern and a brain abscess respectively. Specimen from brain showed Nocardia infection. Therefore, the pulmonary involvement was interpreted as nocardiosis and treated with trimethoprim/ sulfamethoxazole (TMP/SMX). After one year, there was no improvement in pulmonary condition in terms of radiologically and clinically. A CT-guided biopsy from lung lesions was performed and the pathology exam confirmed the diagnosis of PAP. The patient was treated with whole lung lavage and after one-year follow-up she remains symptom-free. PAP is a rare condition, which can be easily missed. Our case highlights the importance of thinking of rare conditions like PAP in patients present with opportunistic infections especially those who are immunocompromised or had occupational exposures to substances like silica. Considering this diagnosis, particularly, when we have no response to empiric anti-biotic therapies, it can lead us to faster diagnosis and more appropriate cure.

Keywords: Pulmonary alveolar proteinosis, Nocardia infection, Brain abscess