Isolated Mediastinal Kocuria rosea Infection Mimicking Malignancies

Abstract

Isolated mediastinal Kocuria rosea infection is a rare condition and presentation can be variable. We report an unusual case of Kocuria rosea infection which presented as solitary pulmonary nodules and isolated lymph node swelling, entirely confined within the tracheal bifurcation and 18-fluoredeoxyglucose position emission tomography and computed tomography (18FDG PET/CT)-avid, thereby mimicking a neoplastic lesion. Owing to the large differential diagnosis, which includes diseases such as pulmonary neoplasia and lymph node metastases, a biopsy via mediastinoscopy was to be attempted, so hopefully avoiding thoracotomy. Histopathology analysis of the resected mediastinal lymph nodes (MLNs) demonstrated no malignant cells, but rather necrotizing MLNs, which is classically associated with Kocuria rosea infection. The patient was asymptomatic and biopsy allowed a precise diagnosis. Kocuria rosea infection is rare; it should be considered when FDG PET shows intense FDG uptake in non-regionally swollen lymph nodes.