Endocrine Abstracts

A 72-year-old male patient was referred to endocrinologist in June 2023. He had known arterial hypertension, aortosclerosis, ascending aorta and aortic valve replacement, chronic cerebral ischemia. In November 2022 stage IV cutaneous melanoma with lung metastasis had been revealed. For 6 months after tumour resection he received anti-PD-1 immune checkpoint inhibitor therapy which was well tolerated. After the 7th cycle of treatment short-term fever and skin rash had appeared, followed by rapid memory deterioration, progressive asthenia, physical and mental slowness during 2 weeks. On examination no signs of brain metastasis, unremarkable complete blood count, normal fasting blood glucose and serum electrolyte levels, but decreased TSH – 0.02-0.005 (normal range 0.27-4.2) IU/l, increased fT4 – 23.6-29.7 (12-22) pmol/l and fT3 – 11.8 (3.1-6.8) pmol/l, negative TPOAb, negative TRAb were found, and the patient was referred to endocrinologist. He presented with psychomotor sluggishness, traces of skin rash, BMI of 28 kg/m², blood pressure of 108/76 mmHg, heart rate of 74 beats per minute, slight hand tremor. No thyroid enlargement or other clinical signs of thyrotoxicosis were revealed. Further testing, administered by endocrinologist, had demonstrated TSH <0.0083 (0.4-4.0) IU/l, fT4 – 17.5 (9-19) pmol/l, fT3 – 6.3 (3.0-5.6) pmol/l, elevated TgAb – 161 (<4.1) IU/ml, low morning plasma cortisol – 34 (101.2 - 535.7) nmol/l and low ACTH (<5 pg/ml) levels with tendency to hypotension. The diagnosis of immunotherapy-induced thyroiditis (hyperthyroid phase) and hypophysitis with the secondary adrenal insufficiency was established. Glucocorticoids (GCs) had been initiated. After 2 months of low-dose GCs treatment his TSH, fT4, prolactin, FSH, LH, K, Na, blood pressure levels were within in the normal range, ACTH remained low – 3.4 (7.2-63.6) pg/ml with improvement in physical and cognitive performance, confirming the diagnosis. GCs treatment and monitoring has been continued. Immune checkpoint inhibitors are increasingly used in cancer therapy. Data accumulation regarding side effects of these drugs is important for early detection and clinical success. Both oncologists and endocrinologists should be aware of various possible endocrine-related adverse effects at any step of treatment, requiring specific individual approach. This case emphasizes that periodic assessment of thyroid and pituitary-adrenal function in such patients is needed because clinical symptoms of endocrine disorders may be unclear, masked, atypical, controversial, or absent, especially in older individuals with multiple co-morbidities.