Background
Adrenal insufficiency of either a primary or secondary origin may culminate in a life-threatening adrenal crisis
Case presentation
Acute presentation
A 46 year old patient was admitted as an emergency with vomiting, hypotension and serum cortisol of 0.940 μg/dl (26 nmol/l) indicative of an adrenal failure. Despite previous history of panhypopituitarism he was found to be hyperthyroid [free T4 6.32 ng/dl (ref. range: 0.93–1.7), free T3 22.21 pg/ml (ref. range: 1.8–4.6)], see Table
Biochemical and hormonal results of patient at the time of diagnosis, after debulking of craniopharyngioma and on the day of emergency admission.
Before surgery
After surgery (one month later)
On admission with adrenal crisis (Five months later)
Reference range
Sodium [mmol/l]
144
139
141
135–150
Potassium [mmol/l]
3.9
4.3
3.9
3.5–5.0
Creatinine [mg/dl]
0.8
0.8
0.9
0.6–1.4
TSH [mU/l]
0.069
0.007
0.010
0.27–4.2
Free T4 [ng/dl]
0.952
1.32
6.32
0.93–1.7
Free T3 [pg/ml ]
1.87
1.52
22.21
1.8–4.6
LH [IU/l]
0.588
<0.100
not assessed
1.7–8.6
FSH [IU/l]
0.530
0.135
not assessed
1.5–12.4
Testosterone [ng/ml]
0.355
0.023
not assessed
2.8 – 8.0
8 am Cortisol [μg/dl]
7.79*
0.168**
0.940
6.2–19.4
Prolactin [ng/ml]
18.56
16.1
not assessed
3.4–24.1
*Without hydrocortisone replacement. In order to covert μg/dl to nmol/l multiply by 27.6
**Hydrocortisone omitted in the afternoon prior to measurement.
Past Medical History
He was fit and well till the age of 45. His height was 183 cm, BMI 25.5 kg/m2. The was no family history of autoimmune disease. Eight months prior to this hospitalisation he presented with diabetes insipidus and was found to have a large cystic tumour in the area of the pituitary gland (presented in Figure
T1-weighted magnetic resonance images of cystic tumour of the described patient
T1-weighted magnetic resonance images of cystic tumour of the described patient. Subsequently this was found to represent craniopharyngioma.
On the day of his emergency admission he looked ill and dehydrated, though was fully conscious and cooperative. Heart rate was 120 beats/min (sinus rhythm), blood pressure 85/40 mm Hg. There were no obvious features of infection, but he was found to have marked tremor and thyroid bruit. Mild lid-lag sign was present, however, without any obvious orbitopathy. He was found to have very low cortisol, with markedly raised free T4 and free T3, as presented in Table
Treatment and Progress
He received treatment with intravenous fluids and hydrocortisone initially 100 mg intravenously every 8 hours for the first 24 hours. L-thyroxine was stopped. Administration of large dose of oral methimazole (60 mg/day) resulted in gradual decrease in free T4 and free T3 (to 1.76 ng/ml, and 5.92 pg/ml, respectively) over a 15-day period, as presented in Table
Iodide uptake scan of the described patient prior to radioiodine administration
Iodide uptake scan of the described patient prior to radioiodine administration. Uniformly increased uptake plus raised titre of anti-TPO and anti-TSHR antibodies were indicative of Graves' disease as the cause of thyrotoxicosis.
Thyroid function tests on the day of an emergency admission of patient and during his hospital stay prior to transfer for radioactive iodine treatment.
Date
TSH [mU/l] (Ref. Range: 0.27–4.2)
Free T4 [ng/dl] (Ref. Range: 0.93–1.7)
Free T3 [pg/ml] (Ref. Range: 1.8–4.6)
11.02.04
0.010
6.32
22.21
16.02.04
-
3.78
10.18
20.02.04
<0.005
2.77
7.93
26.02.04
-
1.76
5.92
Discussion
Our case illustrates development of autoimmune thyrotoxicosis in the setting of known previous panhypopitutarism. From clinical viewpoint, the most important factor is to recognise that such combination of two opposite conditions, i.e., thyrotoxicosis despite previous secondary hypothyroidism is indeed possible. Coexistence of hypopitutarism and thyrotoxicosis, though rare, has been described in literature. Some of these patients, however, developed serious complications, like thyrotoxic coma
There is also evidence of significantly raised prevalence of thyroid disorders in patients with acromegaly, regardless of the preservation of other hormonal axes
The patient described above had coexistent nanhypopituitarism and clinically significant autoimmune thyroid disease. Thyroid hormones are known to increase the turnover of cortisol. Our patient developed marked thyrotoxicosis during the course of Graves' disease, but failed to increase his hydrocortisone replacement. The combination of thyrotoxicosis in the setting of increased cortisol requirements had lead to a vicious circle resulting in life-threatening adrenal crisis.
Conclusion
In summary, we have demonstrated that even severe hypopituitarism does not preclude the development of autoimmune thyrotoxicosis. These conditions are therefore not mutually exclusive and may indeed coexist in the same patient. Our case, therefore, highlights the need for awareness of possible coexistence of these conditions among endocrinologists, neurosurgeons and general physicians.
Consent
Patient's consent have been obtained for publication of this case report.
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
KCL, MM, E S-J and AL personally supervised treatment of the above patient at the time of diagnosis of craniopharyngioma, during his acute admission and during his follow-up in endocrine clinic. All contributed to writing of the paper. JM supervised radioiodine treatment of the patient and contributed to writing of the manuscript.