PLEURAL EFFUSION WITH TRAPPED LUNG ASSOCIATED WITH METHIMAZOLE-INDUCED HYPOTHYROIDISM

Abstract

SESSION TITLE: Tuesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/22/2019 01:00 PM - 02:00 PM INTRODUCTION: Anti-thyroid medications can cause a variety of adverse reactions. There are only a small amount of reported cases associating the thioamides with pleural effusions [1,2,3]. None of these were associated with trapped lung. We present a case of a trapped lung with unclear etiology associated with methimazole and hypothyroidism. CASE PRESENTATION: A 36-year-old male with a history of Type 1 diabetes and Graves' disease status post radio-iodine ablation on methimazole presented to the hospital after one month of shortness of breath and cough with no associated fevers, chills, or night sweats. The patient was found to have a large right pleural effusion with mediastinal shift to the left with a completely collapsed lung. He subsequently had a chest tube placed with four liters fluid drained. Pleural fluid showed an exudative effusion by Light’s Criteria with fluid and serum protein of 4.6 g/dL and 8.6 g/dL respectively. Fluid and protein lactate dehydrogenase (LDH) were 120 U/L and 320 U/L respectively. Pleural glucose was 95 mg/dL and pH was 7.75. Gram stain and cultures were unremarkable. Cytology was non-diagnostic for malignancy. After drainage, the patient’s right lung remained collapsed with quickly reaccumulated effusion. Serum sedimentation rate, quantiferon gold, fluid adenosine deaminase, and fluid amylase were all negative. He was found to be hypothyroid with a thyroid stimulating hormone level of 20.7 IU/mL and free T4 of 0.31 ng/mL and his methimazole was stopped. An autoimmune panel was negative. Due to concern for trapped lung, the patient underwent a video-assisted thorascopic surgery converted to thoracotomy for decortication of the right upper, middle, and lower lobes. After decortication, the patient had increased aeration of the lung with no evidence of consolidation or mass. He was ultimately discharged home with resolution of the hypothyroidism and placed back on methimazole. He has only had recurrence of a mild asymptomatic effusion. DISCUSSION: The exact etiology of the effusion with trapped lung remains unclear in this case. Hypothyroidism may have been a contributing factor for which methimazole may also have been involved. Methimazole has been associated with lupus-like reactions for which pleuritis and effusion could be a possibility. There is no clear evidence that the effusion was from infection. Malignancy is another consideration although fluid analysis was non-diagnostic and no tumor was identified during decortication. With this patient’s recurrent small pleural effusion, it may be beneficial for him to have close monitoring of thyroid levels and dosing of methimazole, especially in the setting of having already experienced a trapped lung. CONCLUSIONS: Methimazole and hypothyroidism may be a cause of pleural effusion and even trapped lung. When evaluating a patient’s effusion, methimazole and possibly the other thioamides must be considered as possible culprits. Reference #1: Lee JH, Park M, Park MJ, Jo YS. Massive pleural and pericardial effusion due to hypothyroidism in a patient with a surgically treated thyroid-stimulating hormone-producing pituitary adenoma. Acta Clin Belg. 2018;73(5):398-401 Reference #2: Da Costa P, Silva F, Henriques J, et al. Methimazole associated eosinophilic pleural effusion: a case report. BMC Pharmacol Toxicol. 2017 Mar;18(1):16 Reference #3: Sen N, Ermis H, Karatasli M, Habesoglu M, Eyuboglu F. Propylthiouracil-associated eosinophilic pleural effusion: a case report. Respiration. 2007;74(6):703-5 DISCLOSURES: No relevant relationships by Waqas Adeel, source=Web Response No relevant relationships by Nathan Brewster, source=Web Response No relevant relationships by Brian Holahan, source=Web Response No relevant relationships by Alaynna Kears, source=Web Response No relevant relationships by Michal Kloska, source=Web Response