Bronchocentric Granulomatosis: The Malignancy Mimicker

SESSION TITLE: Medical Student/Resident Lung Pathology SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Bronchocentric Granulomatosis (BG) is a rare disorder with a wide variety of clinical presentations. It can be subdivided into two epidemiological categories: asthmatic and non-asthmatic. Here, we describe a non-asthmatic with BG whose presentation was concerning for malignancy. CASE PRESENTATION: A 46 year-old male never smoker with a history of bronchiectasis and seizures was referred for abnormal computed tomography (CT) scans of the chest, performed in the context of a 2 year history of dry cough. He had no associated symptoms including wheezing, dyspnea, nasal congestion, acid reflux, and weight loss. Serial CT scans revealed a spiculated nodule in the left upper lobe that had decreased in size but persisted across 2 years. Notably, he had a biological sister who passed away from a biopsy proven small cell lung carcinoma at age 27. Physical examination was unremarkable, as well as pulmonary function testing and serological testing, including a normal eosinophil count. A positron emission tomography (PET) scan showed that the nodule was PET avid with an SUV of 5.74 g/mL. The patient ultimately underwent a left upper lobe trisegmentectomy for the nodule. Pathology revealed necrotizing granulomatous inflammation with destruction of adjacent bronchiolar walls, consistent with BG. Surgical specimen bacterial and fungal cultures were negative. Serum aspergillus antibodies, galactomannan, antineutrophil cytoplasmic antibodies, and rheumatoid factor were also negative. His cough improved after his surgery, and a CT scan done 2 months postoperatively showed no abnormalities other than post-surgical changes. DISCUSSION: Patients with BG commonly present with constitutional symptoms such as fatigue and fever. Respiratory symptoms are reportedly rare, but tend to be seen more commonly in the asthmatic type. A chronic indolent presentation is more common for non-asthmatic patients. Associated etiologies include allergic bronchopulmonary aspergillosis, rheumatoid arthritis, vasculitides, and mycobacterial infections. In the context of such associated diseases, treatment of the underlying cause is imperative. In idiopathic disease, most patients recover without therapy but steroids can also be used. Radiographically BG can present as pulmonary nodules or consolidation, often in the upper lobes. Diagnosis of BG is made based on histopathology of a surgical lung biopsy specimen. It is characterized by peribronchiolar necrotizing granulomatous inflammation, limited to the airway and parenchyma without vascular involvement. CONCLUSIONS: In our case, the pulmonary nodule decreased in size prior to resection, which could represent the spontaneous resolution previously described in idiopathic non-asthmatic patients. This case illustrates that BG should be in the differential diagnosis for patients with a suspected malignant nodule in the absence of clinical symptoms or comorbidities concerning for malignancy. Reference #1: Ohshimo, S., et al. (2017). “Differential diagnosis of granulomatous lung disease: clues and pitfalls: Number 4 in the Series “Pathology for the clinician” Eur Respir Rev 26(145). Reference #2: Mimur, K., et al. (2011). “A case of bronchocentric granulomatosis resembling lung cancer on diagnostic imaging.” Nihon Kokyuki Gakkai Zasshi 49(12): 970-975 Reference #3: Granada, M. and A. C. Theodore (2010). A Case Of Bronchocentric Granulomatosis Following Treatment For Non Hodgkin Lymphoma. C43. Case Reports In Interstitial Lung Disease and More II, American Thoracic Society: A4505-A4505. DISCLOSURES: No relevant relationships by Johanna Ben-Ami, source=Web Response No relevant relationships by Oki Ishikawa, source=Web Response No relevant relationships by Bushra Mina, source=Web Response No relevant relationships by Doaa Morrar, source=Web Response