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.



A case of Primary hyperparathyroidism and subsequent parathyroidectomy

HOSP # WARD Medical Ward
CONSULTANT   Dr. Jody Rusch DOB/AGE 59 Y Male

Abnormal Result

Hypercalcemia with hypophosphatemia

Presenting Complaint

History

This is a patient with parathyroid adenoma (and resulting longstanding hypercalcemia and hypophosphatemia, which is typical). Adenoma was removed yesterday, acc. to what I can see on a frozen section. Phosphate is dropping even more 0.42 mM (0.78 – 1.42) (on bloods taken this afternoon) and it will likely become significantly lower even.

Examination

Laboratory Investigations

PTH was initially significantly raised, although the renal function was normal. This means that there is likely hypercalcemia due to primary hyperparathyroidism.

PTH & Calcium Chart drawn by 100lyric (Please, click on the link to understand the diagram) Primary Hyperparathyroidism Dx: • Increased PTH & Ca++ (>10,5mg/dl) • Low Phospate (
Chart drawn by 100lyric

Other Investigations

Final Diagnosis

Take Home Message

Phosphate supplementation may be quite important as there was longstanding autonomous PTH secretion, depleting stores of phosphate via phosphaturia (also PTH induced). There will likely not be much PTH secretion for some while, hence Vit. D activation will seize and little phosphate absorbed from the GIT due to longstanding lack of phosphate transporters. FGF-23 secretion will also seize and with the lack of PTH, the bone will not resorb and the remodeling process will consume the phosphate in the blood. Most mechanisms to increase phosphate physiologically will likely be dysfunctional at this time. Because he will not adequately absorb phosphate from the GIT (because of failure to activate Vit. D, he may need supplementation of phosphate IV).

Kidneys will however be a bit less phosphaturic (due to lack of PTH), thus he may respond quite well to IV phosphate.