Endocrine

[drnrpatel]

A 65-year-old woman complains of fatigue. She has no prior medical history and is not taking any medications. She denies a recent weight change, heat or cold intolerance, constipation, nausea, vomiting, dyspnea, chest pain, or muscle cramping. She has not noted blood in stool. She is able to perform activities of daily living. Her blood pressure is 115/80 mm Hg and pulse is 65/min. Her neck is supple with no nodules; heart, lung and abdomen examinations are normal. Reflexes are intact. Laboratory studies show a normal thyroid-stimulating hormone level, a normal hematocrit, an elevated calcium level, a low phosphorus level and an undetectable parathyroid hormone level. Which of the following is the most likely diagnosis?



A.

Familial hypocalciuric hypercalcemia


B.

Hyperthyroidism


C.

Hypervitaminosis


D.

Malignancy


E.

Primary hyperparathyroidism

[surez18]

ans D malignancy.. PTHrP secretd by many malignancies....

[dryogi]

C.

Hypervitaminosis

[Dr.A.F.A]

Ithink hypervitaminouses

[drnrpatel]

The correct answer is D. Patients presenting with hypercalcemia and hypophosphatemia typically have a high parathyroid hormone level. Those with hypercalcemia and hypophosphatemia without elevated levels of parathyroid hormone are likely to have hypercalcemia of malignancy. This is associated with many solid tumors including lung and kidney cancer where a parathyroid-related protein is synthesized by the tumors not identified by the currently available assays.
Familial hypocalciuric hypercalcemia (choice A) is an autosomal dominant trait in which patients often have normal or slightly low levels of parathyroid hormone.
Hyperthyroidism (choice B) will cause hypercalcemia as a result of increased bone turnover. This is non-parathyroid hormone related and the phosphorus would not be low. This patient’s thyroid-stimulating hormone is normal as well.
Hypervitaminosis (choice C) causes a non-parathyroid hormone mediated hypercalcemia. The patients would not be expected to have a low serum phosphate.
Primary hyperparathyroidism (choice E) will cause hypercalcemia and hypophosphatemia in the setting of an excess of parathyroid hormone activity