Endocrine Abstracts

A 37-years-old man was referred to rheumatology with a 3 month history of widespread joint pains, worse on rising in the mornings with early morning stiffness lasting about 15 min. Hands were affected first followed by knees and hips. On further questioning, he also complained of generalised fatigue, loss of libido and thinning of the hair on his chest, as well as 15 kg weight loss over 6 months. He recalled a febrile illness with headache prior to the onset of his symptoms, but had no ongoing headache or visual symptoms.

On examination there was no evidence of joint synovitis. Blood testing done by his GP 2 months prior to referral showed: TSH 0.07 μU/ml (0.35–6.9), free T₄ 6.0 pmol/l (5.6–21) and free T₃ 5.1 pmol/l (3.7–7.0). ESR was mildly elevated at 12 mm/h and CRP was 8.0 mg/l. There was a mild normocytic anaemia (Hb 12.1 g/dl). On repeat testing 1 month later TSH was 0.1 μU/ml, free T₄ 3.0 pmol/l, free T₃ 3.0 pmol/l. 9 am blood tests were organised for the following day which showed the following: cortisol 16 nmol/l (138–690), free T₄ 3.0 pmol/l, testosterone <0.3 nmol/l (10–35), LH 0.4 IU/l (2–18), FSH 1.3 IU/l (1–16), prolactin 185 mIU/l (50–500), glucose 5.2 and IGF1 25 μg/l (75–344). X-ray of the joints were normal.

MRI pituitary confirmed a pituitary macroadenoma. Formal visual perimetry was normal. He was subsequently commenced on Hydrocortisone therapy and two weeks later on thyroxine replacement with resolution of joint symptoms. He is awaiting transphenoidal adenomectomy.

Discussion: There are reports of hypopituitarism presenting with musculoskeletal symptoms. These have been attributed mainly to hypothyroidism and hypoadrenalism. Hypothyroidism, as in this case, can present with polyarthralgia/polyarthritis or myalgia/myositis which may be associated with elevated muscle enzymes. Hypothyroidism is also associated with calcium pyrophosphate crystal deposition in joints (presenting as acute pseudogout or a chronic arthropathy) and carpal tunnel syndrome. Hypoadrenalism can produce various nonspecific symptoms including fatigue and myalgias which could lead to patients being referred for rheumatological assessment.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.