Search results
Results from the WOW.Com Content Network
Hypercalcemia of malignancy may also occur due to tumor production of vitamin D or parathyroid hormone. These causes are rare and constitute about 1% of all causes of hypercalcemia of malignancy. [22] Hypercalcemia of malignancy usually portends a poor prognosis, and the medial survival is 25–52 days of its development. [22]
Like hypocalcemia, hypercalcemia can be non-severe and present with no symptoms, or it may be severe, with life-threatening symptoms. Hypercalcemia is most commonly caused by hyperparathyroidism and by malignancy, and less commonly by vitamin D intoxication, familial hypocalciuric hypercalcemia and by sarcoidosis. [2]
Hypercalcemia, elevated blood calcium, has numerous causes, including [5] Elevated levels of parathyroid hormone due to hyperparathyroidism, leading to bone resorption and subsequent hypercalcemia by reducing phosphate concentration. Secretion of parathyroid hormone-related protein by certain tumors. Resorption of bone due to
PTHrP is related in function to parathyroid hormone(PTH). When a tumor secretes PTHrP, this can lead to hypercalcemia. [11] As this is sometimes the first sign of the malignancy, hypercalcemia caused by PTHrP is considered a paraneoplastic phenomenon. PTHrP is responsible for most cases of humoral hypercalcemia of malignancy.
Symptomatic features of paraneoplastic syndrome cultivate in four ways: endocrine, neurological, mucocutaneous, and hematological.The most common presentation is a fever (release of endogenous pyrogens often related to lymphokines or tissue pyrogens), but the overall picture will often include several clinical cases observed which may specifically simulate more common benign conditions.
Dystrophic calcification can occur even if the amount of calcium in the blood is not elevated, in contrast to metastatic calcification, which is a consequence of a systemic mineral imbalance, including hypercalcemia and/or hyperphosphatemia, that leads to calcium deposition in healthy tissues. [2]
Differential diagnoses of hypercalcemia include humoral hypercalcemia of malignancy, renal failure, malignant bone destruction (such as multiple myeloma, metastatic breast cancer, lymphoma), thiazide diuretics, lithium, immobilization, hyperthyroidism, milk alkali syndrome, multiple endocrine adenomatosis syndromes, and granulomatous diseases. [37]
Hyperparathyroidism is present in ≥ 90% of patients. Asymptomatic hypercalcemia is the most common manifestation: about 25% of patients have evidence of nephrolithiasis or nephrocalcinosis. In contrast to sporadic cases of hyperparathyroidism, diffuse hyperplasia or multiple adenomas are more common than solitary adenomas.