Isolated pulmonary amyloidoma: A rare cause of solitary pulmonary nodule

Our plain-English summary of Isolated pulmonary amyloidoma: A rare cause of solitary pulmonary nodule, by D. DeCicco, E. Alshaikhnassir, V. Deepak, et al (Respiratory Medicine Case Reports, 2023).

The study

• Authors: D. DeCicco, E. Alshaikhnassir, V. Deepak, S. Hadique, R. Sangani
• Journal: Respiratory Medicine Case Reports
• Published: 2023;42:101820
• Type of article: Case report
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Pulmonary nodules are a frequent finding on imaging, especially given screening guidelines for lung cancer with low dose computed tomography (CT) scan. Here, we report a case with a single pulmonary nodule in a patient exposed to coal dust and asbestos. The nodule had benign features, but it showed an increase in size on repeated imaging. A CT-guided biopsy followed by mass spectrometry of the sample identified the nodule as the AL subtype of amyloidoma. A bone marrow biopsy was without evidence for malignancy including lymphoma. Nodular pulmonary amyloidosis (NPA) is rare, and a biopsy is required to establish the diagnosis. NPA generally does not affect lung function or impact survival; thus NPA does not require specific therapy. This case is the first documented case associated with coal-dust exposure. High-risk patients need to be followed longitudinally due to association of amyloidosis with lymphoma and other systemic conditions.

© 2023 The Authors.

In plain English

This is a case report about one patient, by authors at West Virginia University. A 76-year-old man had a lung nodule and shortness of breath that had worsened over about six months. He had been exposed to coal dust and asbestos (fiber type not stated) as a miner for nine years and a welder for twenty years. He had smoked five pack-years and quit 50 years earlier. A CT scan showed a 2.0 by 1.5 cm, partly calcified right lower lobe nodule. It was stable at 3 months but measured 3.0 by 1.7 by 1.5 cm at 9 months. A CT-guided biopsy found amyloid, an abnormal protein deposit, which the authors describe as AL amyloidosis. Further tests found no amyloidosis elsewhere in the body, and bone marrow biopsy and flow cytometry showed no evidence of malignancy, including lymphoma. The final diagnosis was nodular pulmonary amyloidosis; later CT showed the nodule stable. The authors stated this was the first reported case linking coal exposure with this condition. They said such nodules need long-term follow-up. The report describes one person and measures no risk.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: case report (single patient)
• Who was studied: One 76-year-old man with type 2 diabetes, hypertension and hyperlipidemia, evaluated at a pulmonary clinic for a lung nodule and chronic shortness of breath. The authors are at West Virginia University, USA.
• Exposure: Coal dust and asbestos (fiber type not stated) from nine years working as a miner and twenty years as a welder. He also had a five pack-year smoking history and had quit 50 years earlier.
• Main results:
  • CT of the chest showed a 2.0 by 1.5 cm elongated, partially calcified nodule in the right lower lobe along the right major fissure. There was no significant mediastinal or hilar lymph node enlargement.
  • The nodule was stable at 3 months but had grown to 3.0 by 1.7 by 1.5 cm at the 9-month follow-up.
  • A CT-guided biopsy showed amyloid protein. Congo red staining was positive, with apple-green birefringence under polarization consistent with amyloid deposition.
  • Systemic amyloidosis was ruled out. Serum and urine protein electrophoresis and serum immunoglobulins were normal, and the echocardiogram excluded cardiac amyloidosis.
  • The protein electrophoresis tests and flow cytometry from the bone marrow biopsy showed no indication of malignancy, including lymphoma.
  • Pulmonary function tests showed mild obstruction with a significant bronchodilator response, and he was started on maintenance inhalers.
  • The final diagnosis was nodular pulmonary amyloidosis (NPA). On follow-up CT the nodule was stable in size.
• The authors' conclusion: The authors stated that this is the first case reporting coal exposure associated with NPA. They concluded that recognizing localized pulmonary amyloidoma matters because patients need long-term follow-up.

Topics

Medical terms in this study, explained in our Lexicon: Lung Cancer, Biopsy.

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