Endocrine Abstracts

JOINT1979

Introduction: In prolactinoma patients, first-line therapy typically involves cabergoline (CAB) or bromocriptine. Adverse effects occur in 2.5-29% of CAB-treated patients. While CAB is generally safe regarding pleuropulmonary side effects, this case highlights its rare association with toxic pneumonitis, emphasizing the need for awareness of such adverse reactions despite limited available data.

Case: A 77-year-old man was diagnosed in 2019 with clear cell renal cell carcinoma and lung metastases (pT3aN0MxLVIR0 G3). Surgical treatment and first-line therapy with Sunitinib were administered. In 2022, the patient was diagnosed with nodular goiter, Hashimoto’s thyroiditis, and hypothyroidism, treated with Levothyroxine to achieve euthyroidism. Galactorrhea was present, accompanied by hyperprolactinemia and a pituitary microadenoma. Bromocriptine was initiated but discontinued due to intolerance. The medication was replaced with CAB at 125 µg/week, gradually increasing the dose to 500 µg/week. Galactorrhea resolved, but the patient developed dyspnea, cough, and chest pain without fever. Blood tests CRP 4.2 (<5) mg/l, K 4.5 (3.5-5.1) mmol/l, Na 139 (136-146) mmol/l, creatinine 110 (59-104) µmol/l, leukocytes 8.6x10^9/l(3.9-8.8), neutrophils 6.4x10^9/l(1.8-7.4). Inflammatory markers within normal range. Blood gas analysis pH 7.38 (7.35-7.45), pCO2 39 (35-45) mmHg, pO2 92 (80-100) mmHg, HCO3- 24 (22-26), BE -1.6 (-2-+2) mEq/l, SaO2 98 (95-100)%. ECG Demonstrates normal findings. Echocardiography Ejection fraction 55%, impaired diastolic function. Chest CT Broad irregular areas with consolidation and bronchograms were predominantly observed in the right lung, with similar findings bilaterally, suggesting organizing toxic pneumonitis without tumor progression. Radiological and biochemical findings indicated cabergoline-induced toxic pneumonitis, leading to medication discontinuation. Follow-up Symptoms of toxic pneumonitis resolved within two weeks, with follow-up chest CT at one month showing resolution of pulmonary changes. In dynamic monitoring, prolactin levels increased without galactorrhea, and dopamine agonists were not resumed. After 1 year, pituitary MRI showed no significant adenoma size change, prompting continued active monitoring.

Conclusions: This case highlights the rare association between CAB and toxic pneumonitis, emphasizing the need for clinicians to stay vigilant for pulmonary side effects in patients on cabergoline, especially with respiratory symptoms. Early detection and discontinuation of the medication are key to mitigating these adverse effects.