ACUTE AMIODARONE TOXICITY PRESENTING AS A LUNG MASS

Abstract

TOPIC: Imaging TYPE: Medical Student/Resident Case Reports INTRODUCTION: We present a very uncommon case of lung mass developed within a month of starting amiodarone in an elderly male. CASE PRESENTATION: An 82-year-old male with a past medical history of end-stage renal disease on hemodialysis, congestive heart failure, diabetes mellitus, coronary artery disease, atrial fibrillation on amiodarone (200mg/day started a month ago) presented with dry cough and altered mental status for one day. On exam, he appeared tachypneic and drowsy with mild bibasilar lungs crackles. Laboratory findings included WBCs 4.8 K/UL, procalcitonin 0.3 ng/ML with sterile blood, urine, and respiratory cultures. Chest x-ray showed a new right upper lobe opacity with persistent bilateral lower lobes congestion (figure 1a). Computerized tomography (CT) of the chest showed dense, irregular soft tissue mass with high attenuation at the right apex and adjacent smaller spiculated nodules compatible with the deposition of amiodarone (figure 1b). Pulmonary and cardiology services advised stopping amiodarone with no further intervention. Bronchoscopy and biopsy were not done due to poor cardiac function. He was discharged to a nursing home after a significant improvement in his symptoms. On follow up after a year, patient had complete resolution of the symptoms. DISCUSSION: Amiodarone is a widely used iodinated antiarrhythmic agent with significant side effects due to its deposition in various organs including lungs (4-17%). Organ toxicity may occur from direct cytotoxicity or T-cell mediated hypersensitivity reaction. Though there is no safe dose, amiodarone associated pulmonary toxicity is mostly suspected in patients taking a daily dose of 400 mg for more than 2 months or any dose for more than 2 years [1,2]. Life-threatening and irreversible pulmonary toxicity is frequently associated with older age, longer duration of treatment, high dosage, and pre-existing lung disease. Diagnosis is made after the exclusion of other causes in patients presenting with nonproductive cough and/or dyspnea, new chest imaging findings, biopsy showing lipid-laden foamy macrophages. Once identified, significant improvement is noted with the withdrawal of the drug. Several patterns of lung inflammation including interstitial or organizing pneumonia, pleural effusion, nodule, or mass-like lesions are evident [3]. High density (> 80 Hounsfield units) lung nodules due to iodinated-amiodarone accumulation are appreciated more on high-resolution chest CT with typical findings frequently in the upper lobes as seen in our case [3]. The mainstay of treatment includes discontinuation of the drug with or without oral steroids. Patient education, regular follow up with chest imaging and use of lowest effective doses are key in reducing its adverse effects [3]. CONCLUSIONS: Given the condition is reversible and curable; the author wants to highlight the importance of early diagnosis of the case for a favorable prognosis. REFERENCE #1: Jessurun GA, Crijns HJ. Amiodarone pulmonary toxicity. BMJ. 1997;314(7081):619-620. doi:10.1136/bmj.314.7081.619 REFERENCE #2: Schwaiblmair, M., Berghaus, T., Haeckel, T. et al. Amiodarone-induced pulmonary toxicity: an under-recognized and severe adverse effect?. Clin Res Cardiol 99, 693–700 (2010). https://doi.org/10.1007/s00392-010-0181-3 REFERENCE #3: Jarand J, Lee A, Leigh R. Amiodaronoma: an unusual form of amiodarone-induced pulmonary toxicity. CMAJ. 2007;176(10):1411-1413. doi:10.1503/cmaj.061102 DISCLOSURES: No relevant relationships by Kabu Chawla, source=Web Response No relevant relationships by Resha Khanal, source=Web Response No relevant relationships by Sharad Oli, source=Web Response No relevant relationships by Shital Oli, source=Web Response No relevant relationships by Shaurya Sharma, source=Web Response