NOCARDIA INFECTION PRESENTING AS AN INVASIVE PULMONARY MASS IN AN IMMUNOCOMPROMISED HOST

TOPIC: Chest Infections TYPE: Fellow Case Reports INTRODUCTION: Pulmonary nocardiosis is an uncommon disease with a diverse range of radiographic appearances. We report interesting case pulmonary in renal transplant patient presenting as dense, rapidly enlarging anterior lung mass invasion into the chest wall. CASE PRESENTATION: Our 41-year-old male history autosomal dominant polycystic kidney (ADPKD) for which he received direct donor 7 years prior to this presentation. His immunosuppressive regimen included tacrolimus, mycophenolate, and prednisone. He presented discomfort was found have large right upper lobe mass. Given his immunosuppressed state, malignancy, post-transplant lymphoproliferative disorder, fungal infections were initially highest on differential. Transbronchial biopsies performed utilizing radial EBUS non-diagnostic, revealing only benign tissue negative special stains bacteria, fungi, mycobacterium. A CT guided core biopsy showed organizing pneumonia focal necrosis favoring infectious etiology. During process completed course antibiotic therapy outpatient, but returned just 2 weeks after discharge worsening pain. Repeat imaging demonstrated that lesion had grown substantially, MRI noted new wall pectoralis muscle. repeat dense inflammation, granulation neutrophil infiltration. The specimen sent specialty laboratory broad PCR testing all cultures serologies etiologies thus far. admission, clinically deteriorated high grade fevers, pain, hypoxic respiratory failure septic shock requiring ICU admission. improved treatment broad-spectrum antibiotics ultimately discharged extended amoxicillin clavulanate (later transitioned trimethoprim-sulfamethoxazole). continued improve positive Nocardia farcinica or N. kroppenstedtii. DISCUSSION: Diagnosis difficult, particularly immunocompromised individual where presentations are diverse.2 In our patient, mass-like across planes (a feature more commonly described it's close relative - Actinomyces). Cell mediated immunosuppression used patients has been associated invasive form including empyema necessitans.1 Broad can be helpful diagnosis challenging cases. CONCLUSIONS: given wide clinical presentations. REFERENCE #1: Lerner PL. Nocardiosis. Clin Infect Dis. 1996;22:891-905. #2: Liu B et al. findings nocardiosis: 9 cases." J Thorac 2017;9:4785-4790. [PMC5720996] DISCLOSURES: No relevant relationships by Janine Vintch, source=Web Response Kenneth Woo,