C40-35 Extensive Pulmonary Granulomas: A Case Without a Culprit

Abstract Introduction Pulmonary granulomatous disease encompasses a wide spectrum of disorders characterized by granuloma formation in the lungs. Etiologies include infectious causes such as mycobacteria and fungi, and non-infectious causes such as sarcoidosis, vasculitis, hypersensitivity pneumonitis, and malignancy. However, in many cases an underlying cause remains obscure. We describe a case of extensive pulmonary granulomas of unclear etiology. Case A 25-year-old male with a history of recurrent childhood pneumonia presented in an outpatient setting with recurrent symptoms of fatigue, dry cough, night sweats, pleuritic chest pain, and unintentional weight loss. His symptoms started nine months prior to presentation when he received amoxicillin and azithromycin. He initially improved after completing this course, then worsened the month leading up to presentation. He took another antibiotic course with doxycycline and augmentin, which did not provide relief. His symptoms rapidly worsened. He denied tobacco use and other substance use. He was a physics student who worked with unknown chemicals under fume hoods. CT chest revealed multiple impressive bilateral consolidative masses (Figure 1). Transbronchial cryobiopsies demonstrated extensive well-formed non-necrotizing granulomas without evidence of atypia or malignancy. Histology and cultures were negative for bacteria, fungi, AFB, and Nocardia. Serologic testing for vasculitis, fungal serologies, and immune deficiency were normal. Typical imaging findings of sarcoidosis such as mediastinal lymphadenopathy, perivascular infiltration, or extra-pulmonary manifestations such as erythema nodosum or uveitis, were not noted. Nodular sarcoidosis was considered; however, this usually follows a benign clinical course with spontaneous resolution. Typical findings of hypersensitivity pneumonitis such as ground-glass opacities and centrilobular nodules, or traction bronchiectasis and honeycombing in cases of fibrosis, were not noted. Given the absence of an identifiable cause of his granulomatous disease, he was empirically treated with a prednisone taper. Repeat CT chest showed marked radiographic improvement which coincided with symptom relief. Figure 1. Discussion This case is crucial to report as this patient was found to have extensive, progressive pulmonary lesions which caused significant symptoms, with unclear etiology. A retrospective study published in 2011 analyzed pathological specimens of pulmonary granulomas from 500 cases across seven countries and found the most common causes were sarcoidosis (27%) and mycobacterial or fungal infections (25%). Strikingly, 42% of cases did not have a definitive etiology, as seen in this patient. This case emphasizes the necessity for increased reporting and analysis of pulmonary granulomatous disease. This abstract is funded by: None