Abstract
BackgroundImmunotherapy treatment with immune-checkpoint blockade has become a new paradigm in cancer treatment. Despite its efficacy, it has also given rise to a new class of adverse events, immune-related adverse events, which may affect any organ, including the thyroid and the pituitary.Case presentationWe present a case of a 77-year-old Caucasian man with metastatic renal cell carcinoma on immunotherapy treatment who was admitted to our hospital with a severe persistent headache of sudden onset. He had been on corticosteroid therapy for 10 days for suspected immune-related thyroiditis. The patient had tachycardia and mild diarrhea, and his thyroid function tests were compatible with subclinical hyperthyroidism with a suppressed thyroid-stimulating hormone level of 0.01 μIU/ml (0.4–4.5), a raised free T4 level of 2.17 ng/dl (0.7–1.9), and a free T3 level of 4.66 pg/ml (2.27–5). Computed tomography and magnetic resonance imaging revealed an enlargement of the pituitary gland compatible with macroadenoma. In the face of a probable immune-related hypophysitis, high-dose corticosteroid treatment was started. A posterior hormonal evaluation revealed secondary hypothyroidism with a suppressed thyroid-stimulating hormone level of 0.11 μIU/ml (0.4–4.5) and low thyroid hormones, a normal free T4 level of 1.02 ng/dl (0.7–1.9), and a low free T3 level of 1.53 pg/ml (2.27–5). These new findings suggested central hypothyroidism possibly due to pituitary apoplexy as a complication of the macroadenoma. Therefore, levothyroxine substitution was started along with the previously started corticosteroid therapy. The patient’s headache and asthenia gradually resolved, and after a few days, he was released from the hospital with levothyroxine substitution and corticosteroid tapering.ConclusionsThis case emphasizes the importance of the differential diagnosis when dealing with patients on immune checkpoint inhibitors because other non-immune-related events may present. Our patient was finally diagnosed with immune-related hyperthyroidism and a concurrent pituitary macroadenoma. This case also highlights the importance of a prompt start of corticosteroid therapy once immune-related adverse events such as hypophysitis are suspected, because otherwise the outcome would be fatal.
Highlights
Immunotherapy treatment with immune-checkpoint blockade has become a new paradigm in cancer treatment
Our patient was diagnosed with immune-related hyperthyroidism and a concurrent pituitary macroadenoma
This case highlights the importance of a prompt start of corticosteroid therapy once immune-related adverse events such as hypophysitis are suspected, because otherwise the outcome would be fatal
Summary
This case shows the difficulty of the differential diagnosis when dealing with patients on immunotherapy It highlights the importance of the prompt start of corticosteroid therapy once an irAE such as immune-related hypophysitis is suspected, because otherwise the outcome could be fatal. In addition to irAEs, it is important to take into account that other pathologies such as a pituitary macroadenoma may develop in oncologic patients treated with immunotherapy. It emphasizes how critical a close thyroid function monitoring is when dealing with this type of drug. Author details 1Medical Oncology Department, Hospital Universitario 12 de Octubre and Instituto de Investigación i+12, Madrid, Spain. Author details 1Medical Oncology Department, Hospital Universitario 12 de Octubre and Instituto de Investigación i+12, Madrid, Spain. 2Internal Medicine Department, Hospital Universitario 12 de Octubre, Madrid, Spain
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