Hypercalcemia in a 56-Year-Old Female (Case 15)

Chapter 26 Hypercalcemia in a 56-Year-Old Female (Case 15)

Walter E. Pofahl, II, MD, Rita El-Hajj, MD

Differential Diagnosis

Endocrine Conditions Malignancy Exogenous Agents
Primary hyperparathyroidism (PHPT) Humoral Thiazide diuretics
Bone metastases Lithium
Vitamin A
Vitamin D

Speaking Intelligently

As a surgeon, when I am asked to see a patient with hypercalcemia, I try to determine the etiology, whether it relates to a potentially surgically correctable condition (primary hyperparathyroidism [PHPT]) and if parathyroidectomy is appropriate. PHPT and malignancy account for the vast majority of cases of hypercalcemia. Determining the etiology is usually fairly straightforward: in PHPT there is inappropriate elevation of parathyroid hormone (PTH) despite hypercalcemia; in hypercalcemia of malignancy (usually seen in advanced stage cancers), PTH is suppressed.

PATIENT CARE

Clinical Thinking

• Primary HPT is due to autonomous PTH secretion despite hypercalcemia. This is typically due to a benign parathyroid adenoma, but can also be caused by parathyroid gland hyperplasia.
• Secondary HPT is due to PTH hypersecretion in response to hypocalcemia, hyperphosphatemia, and/or vitamin D deficiency. The most common cause of secondary HPT is chronic renal insufficiency, and you will usually identify these patients easily as they are on hemodialysis. Secondary HPTH does not cause hypercalcemia. (Calcium is usually low or normal.)
• Tertiary HPT develops in patients with long-standing secondary HPT. In this condition, hypercalcemia occurs due to loss of physiologic regulation of PTH secretion.

History

• Hx is directed at determining etiology. Although most patients seen today with hypercalcemia are asymptomatic, it is still useful to document any of the classical symptoms (“moans, stones, and groans”) related to the common target organs (CNS, renal, and bone).
• Is there a hx of malignancy or family hx of inherited endocrine disorder? (think multiple endocrine neoplasia syndromes)
• A detailed medication hx, including nonprescription medication, herbals, and vitamins, should be obtained. Symptoms of other head and neck conditions such as thyroid nodules that might require intervention should be determined.

Physical Examination

• Examination is directed at detecting neck masses that may require evaluation.
• Thyroid nodules are common.
• Palpating a parathyroid adenoma would be rare and would suggest a parathyroid cancer.
• Physical examination is also directed at detecting a metastatic malignancy that may be the cause of hypercalcemia.

Tests for Consideration

• Electrolytes: Confirms hypercalcemia, hypophosphatemia, and assesses renal function.
 $12
• Albumin: Used to calculate corrected serum calcium level [((4 − patient albumin) × 0.8) + patient calcium].
 $5
• Intact PTH: Confirms/refutes hypercalcemia due to HPTH.
 $60
• Rapid PTH: Used intraoperatively to assess change in PTH level after an adenoma is removed. The PTH should drop 50% by 5 minutes after the adenoma is excised. If it doesn’t drop, the adenoma wasn’t removed, or there is another adenoma present.
 $165
• PTH-related peptide (PTHrP): The humoral factor responsible for the majority of cases of hypercalcemia due to malignancy.
 $75
• 25-OH vitamin D: Low vitamin D levels can cause secondary HPTH and can also affect intraoperative PTH responses.
 $25
• 24-hour urine calcium and creatinine: This test is useful to identify patients with familial hypocalciuric hypercalcemia (FHH)
 $45

IMAGING CONSIDERATIONS

→ Bone mineral densitometry: Easily obtained scan of hip or spine with low-dose dual isotope radiation. No images. Report compares bone density to normal standards for age and sex.
 $275
→ Parathyroid nuclear scan: A nuclear medicine scan of the neck using a special radioactive imaging agent: technetium 99m sestamibi. Sestamibi scans may be performed in dual phase or use SPECT technology such that the imaging techniques are controversial. Thallium 201 subtraction imaging is still in use but less common.

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Mar 20, 2017 | Posted by in GENERAL SURGERY | Comments Off on Hypercalcemia in a 56-Year-Old Female (Case 15)

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