A rare etiology of pulmonary nodules

Arashdeep Rupal; Harpreet Singh; Chinmay Jani; Omar Al Omari; Dipesh Patel; John Perry; Carey C Thomson

doi:10.1016/j.rmcr.2021.101519

A rare etiology of pulmonary nodules

Respir Med Case Rep. 2021 Sep 22:34:101519. doi: 10.1016/j.rmcr.2021.101519. eCollection 2021.

Authors

Arashdeep Rupal^{1

2}, Harpreet Singh³, Chinmay Jani^{1

2}, Omar Al Omari^{1

2}, Dipesh Patel^{4

2}, John Perry⁵, Carey C Thomson^{1

2

6}

Affiliations

¹ Department of Medicine, Mount Auburn Hospital/Beth Israel Lahey Health, Cambridge, MA, USA.
² Harvard Medical School, Boston, MA, USA.
³ Division of Pulmonary and Critical Care Medicine, Medical College of Wisconsin, Froedtert Hospital, Milwaukee, WI, USA.
⁴ Department of Radiology, Mount Auburn Hospital/Beth Israel Lahey Health, Cambridge, MA, USA.
⁵ Department of Pathology, Mount Auburn Hospital/Beth Israel Lahey Health, Cambridge, MA, USA.
⁶ Division of Pulmonary and Critical Care Medicine, Mount Auburn Hospital/Beth Israel Lahey Health, Cambridge, MA, USA.

Abstract

Introduction: Pulmonary nodules are a frequent finding on chest imaging studies, with differential including multiple benign entities, but malignancy is often also a concern. Computed Tomography (CT) and Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET) scans have improved the characterization of pulmonary nodules. However, many nodules remain indeterminate and require periodic monitoring. Here we report two nodular pulmonary amyloidosis cases as a rare etiology of enlarging pulmonary nodules with FDG avidity.

Case presentation: Case 1: 75-year-old woman with a history of asthma, emphysema, bronchiectasis, and a 48 pack-year smoking history was found to have subcentimeter groundglass pulmonary nodules in the right lower lobe (RLL). Follow-up imaging demonstrated an increased solid component of a RLL bulla associated with mild FDG uptake on PET scan. A CT-guided biopsy revealed amyloid deposition. Case 2: 77-year-old man with a history of interstitial lung disease, asbestos exposure, prior tobacco use, and atrial fibrillation treated with amiodarone was found to have a 1.6cm RLL nodule. Follow-up imaging identified an interval increase to 2.0cm associated with moderate FDG uptake on PET scan. Transthoracic biopsy identified amyloid deposition.

Discussion: Nodular pulmonary amyloidosis is a rare form of amyloidosis which may present as an enlarging pulmonary nodule with FDG avidity, raising concern for malignancy. A CT-guided biopsy is a safe way to establish a diagnosis. Recent studies have demonstrated an association between nodular pulmonary amyloidosis and marginal zone lymphomas, which warrants longitudinal follow-up for evolution to lymphoproliferative disorder.

Keywords: AL, Amyloid light-chain; CT, Computed Tomography; FDG, Fluorodeoxyglucose; FISH, Fluorescence In-situ hybridization; FLC, Free Light Chain; Lung cancer; MALT, Mucosa-Associated Lymphoid Tissue; Marginal zone lymphoma; Nodular pulmonary amyloidosis; PET, Positron Emission Tomography; Pulmonary amyloidosis; Pulmonary nodule; RLL, Right Lower Lobe; SPEP, Serum Protein Electrophoresis; SUV, Standardized Uptake Value; TTE, Trans-Thoracic Echocardiography.

Publication types

Case Reports