Endocrine Abstracts

Introduction: Pericardial effusion is a well-documented but increasingly uncommon manifestation of hypothyroidism, due to earlier detection through routine thyroid function tests. We present a case of newly diagnosed severe hypothyroidism presenting with cardiac tamponade, abdominal ascites and pleural effusions.

Case Presentation: A woman in her late 30s presented to the Coronary Care Unit with dyspnoea and a large pericardial effusion detected on transthoracic echocardiography. Over the past 6 months, she had developed progressive abdominal bloating, anorexia, constipation and noticeable weight loss. On examination, she was hypothermic (34.8^oc, later 32.9^oc), with BP 130/106, HR 77/min, RR 15/min, and SpO2 95%. Physical examination revealed abdominal ascites, non-pitting lower limb oedema to the shins, slow motor movements, and an apathetic affect. Laboratory tests revealed severe primary hypothyroidism, with markedly high TSH (>150 mU/l), low FT4 (<0.2 pmol/l) and low T3 (<0.3 pmol/l). Random cortisol levels were within normal range. CT thorax, abdomen and pelvis showed gross circumferential pericardial effusion (maximal depth 54mm) with right ventricular flattening consistent with cardiac tamponade, along with large volume ascites, and bilateral pleural effusions. No solid masses or lesions were identified. Urgent pericardiocentesis yielded sterile, protein-rich fluid (albumin 45 g/l, LDH 246 g/l, glucose 2.6 mmol/l, and total protein 78g/l). The patient was appropriately started on oral levothyroxine therapy, with intramuscular administration considered due to progressing myxedema psychosis and non-compliance.

Discussion: This case highlights an atypical first presentation of hypothyroidism involving multi-serous effusions and paradoxical weight loss. The patient had no previous thyroid function tests so the duration of her hypothyroidism could not be ascertained, however the presence of cardiac tamponade suggests long-standing disease. Progression to cardiac tamponade is rare and requires urgent pericardiocentesis. Pericardial effusions secondary to hypothyroidism that do not cause tamponade typically resolve with thyroid replacement therapy alone.