Quadruple-H

HOSP # 42170712 WARD Endocrinology OPD
CONSULTANT   Dr. Heleen Vreede DOB/AGE 37y female

Abnormal Result

  • The patient’s calcium measured 2.91 mmol/L on two occasions, with PTH measuring 40.6 pmol/L
  • VitD 13.6 (<50 = deficient)
  • TFT’s TSH 0.01 T4 26.7pmol/L

Presenting Complaint

Presented at the GIT clinic in Feb 2020 with persistent vomiting and abdominal cramps, which was ongoing since November 2019.

History

  • Patient was diagnosed with hypertension in her early 20’s.
  • Initiated on HCTZ – subsequently changed to Atenolol 25mg dly – not overweight at the time
  • Gastroscopy was normal
  • No psychiatric symptoms reported – mood swings are reported occasionally by the family
  • Oligomenorrhoea – started in 2019 – nothing else wrong was noted.
  • Normal menarche – normal regular menses until the diagnosis of hypertension was made.
  • Amenorrhoeic last 4 years on no medication currently

Examination

  • Increased BMI – quite significantly increased
  • BP 170/90
  • Skin: Significant amount of skin tags, acanthosis nigricans
  • No striae or bruising
  • No Sx of thyroid disease.
  • Physical examination unremarkable.
  • Normal pulses
  • Essentially a normal examination other than the high BMI

Laboratory Investigations

Repeated bloods (5 days after initial presentation): 

  • TSH 3.13 T4 12.5
  • PTH 28 pmol/L (1.6 -6.9)
  • Ca 2.79
  • Inorganic phosphate 0.77 L mmol/L (0.78 – 1.42)
  • LFT’s: Normal
  • Creat Normal
  • U-Ca 5.6 (no creatinine to compare ratio)
  • FSH 3.2 IU/L
  • LH 2.0 IU/L
  • E2 244 pmol/L
  • Dehydroepiandrosterone sulphate (DHEAS) 2.4 umol/L (1.7 – 9.2)
  • Testosterone 0.5 nmol/L (0.3 – 1.7)
  • SHBG 25.9 L nmol/L (32.4 – 128.0)
  • Prolactin 11.5
  • TSH-Receptor antibodies: Negative

Other Investigations

The patient still had occasional vomiting, abdominal cramps and unexplained muscle pain – other electrolytes apart from calcium, magnesium and phosphate is also advised, as is osmolarity as fluid and electrolyte imbalance may be an effect, rather than a cause of the nausea, vomiting and muscle pain – the sodium and potassium was normal however.

See below, for the hypertension, phaeochromocytoma can be excluded by a 24-hour fractionated urinary metanephrines analysis.

Final Diagnosis

  • Primary hyperparathyroidism is on top of the differential diagnosis and is likely the cause of the raised total calcium.
  • Another cause of the raised blood pressure could very likely be a phaeochromocytoma.
  • It was also advised for replacement of Vitamin D, after a repeat measurement.
  • Other features of MEN-1 syndrome needs to be excluded.

Take Home Message

For phaeochromocytoma, 3 separate days’ urine collection is recommended if the suspicion is high, which it isn’t in this case. This increases the sensitivity of the test.

Before testing for MEN-1: one needs to correct Calcium first – since the hypercalcemia could exacerbate gastrin levels.

Increased serum calcium and hypophosphatemia is the net-result of increased PTH. Urinary phosphate will also be high if measured.