Calcium Carbonate Toxicity: The Updated Milk-Alkali Syndrome; Report of 3 Cases and Review of the Literature

ObjectiveTo describe 3 patients with calcium carbonate-induced hypercalcemia and gain insights into the cause and management of the milk-alkali syndrome.MethodsWe report the clinical and laboratory data in 3 patients who presented with severe hypercalcemia (corrected serum calcium ≥ 14 mg/dL) and review the pertinent literature on milk-alkali syndrome.ResultsThe 3 patients had acute renal insufficiency, relative metabolic alkalosis, and low parathyroid hormone (PTH), PTH-related peptide, and 1,25-dihydroxyvitamin D concentrations. No malignant lesion was found. Treatment included aggressive hydration and varied amounts of furosemide. The 2 patients with the higher serum calcium concentrations received pamidronate intravenously (60 and 30 mg, respectively), which caused severe hypocalcemia. Of the 3 patients, 2 were ingesting acceptable doses of elemental calcium (1 g and 2 g daily, respectively) in the form of calcium carbonate. In addition to our highlighted cases, we review the history, classification, pathophysiologic features, and treatment of milk-alkali syndrome and summarize the cases reported from early 1995 to November 2003.ConclusionMilk-alkali syndrome may be a common cause of unexplained hypercalcemia and can be precipitated by small amounts of orally ingested calcium carbonate in susceptible persons. Treatment with hydration, furosemide, and discontination of the calcium and vitamin D source is adequate. Pamidronate treatment is associated with considerable risk for hypocalcemia, even in cases of initially severe hypercalcemia. (Endocr Pract. 2005;11: 272-280)     

Nicotine-Substitute Gum-Induced Milk Alkali Syndrome: A Look at Unexpected Sources of Calcium

ObjectiveThis report describes a 64-year-old woman with recurrent hypercalcemia. Her laboratory evaluation was consistent with milk-alkali syndrome. It was eventually discovered that the source of the excessive calcium consumption was nicotine-replacement chewing gum and carbonated water.MethodsAn extensive literature search was performed to see if milk-alkali syndrome due to nicotine-replacement gum and carbonated water has been previously reported.ResultsNo prior report describing the association of milk alkali syndrome with nicotine-replacement gum and carbonated water was found.ConclusionsWe present a unique case of milk-alkali syndrome due to nicotine-replacement gum and carbonated water. It serves as a lesson to evaluate other sources besides calcium supplements as the cause of excessive calcium intake.     

A case of hypocalciuric hypercalcemia without family history.

Familial hypocalciuric hypercalcemia (FHH) is usually characterized by asymptomatic hypercalcemia, mild hypermagnesemia, and low urinary calcium excretion, and is occasionally associated with pulmonary fibrosis. It is inherited as an autosomal-dominant, and no sporadic case of hypocalciuric hypercalcemia has been heretofore reported. This report describes a patient with hypocalciuric hypercalcemia completely compatible with FHH but with no family history, suggesting that the most likely diagnosis is "nonfamilial" hypocalciuric hypercalcemia. We propose that the urinary excretion of calcium be examined in all patients with hypercalcemia, hypophosphatemia, and increased PTH before neck surgery, even if patients have no family history of hypercalcemia.     

Familial benign hypercalcemia--from clinical description to molecular genetics.

Familial benign hypercalcemia (or familial hypocalciuric hypercalcemia), a syndrome of lifelong hypercalcemia inherited as an autosomal dominant trait, is distinct from the multiple endocrine neoplasia syndromes and other forms of inherited parathyroid disease. Familial benign hypercalcemia results from the inappropriate secretion of parathyroid hormone despite hypercalcemia, enhanced renal tubular reabsorption of calcium (independent of parathyroid hormone), and apparent tissue resistance to adverse effects of hypercalcemia. Heterozygosity for the familial hypercalcemia trait is benign, although homozygosity for the trait may lead to severe neonatal primary hyperparathyroidism. Genetic linkage studies show that most persons affected with familial hypercalcemia have a mutation on the long arm of chromosome 3 (3cen-q21), although one phenotypically indistinguishable family appears to have a mutation on the short arm of chromosome 19 (19p), and another family has neither 3q nor 19p mutations. One group has recently shown mutations in a putative parathyroid cell-surface calcium receptor that are plausible causes for the chromosome 3q variant of the familial hypercalcemia syndrome. Perhaps the other genes for this syndrome encode proteins representing hitherto-unknown regulators of systemic calcium metabolism independent of parathyroid cell calcium sensing or proteins involved in signal transduction from the calcium receptor.     

Pamidronate: Treatment for severe hypercalcemia in neonatal subcutaneous fat necrosis

BACKGROUND: Subcutaneous fat necrosis (SCFN) of the newborn is an uncommon disorder that occurs in the first weeks of life after foetal distress. It can be complicated by potentially life-threatening hypercalcemia. Treatments of hypercalcemia have included hydration, furosemide and corticosteroids. Only one report has described the use of intravenous bisphosphonates for this condition. We propose that pamidronate could be the first line therapy for severe hypercalcemia in SCFN. PATIENTS AND RESULTS: Four newborns presented between 2001 and 2004 with SCFN complicated by severe hypercalcemia. At diagnosis, ionized calcium levels were higher than 1.4 mmol/l and were associated with high urinary calcium/creatinine ratios and high 1,25-dihydroxyvitamin D levels. Despite treatment with IV fluids, low calcium diet and furosemide, calcium levels remained high. The patients were given 3-4 doses (0.25-0.50 mg/kg/dose) of pamidronate. Urinary calcium/creatinine ratios and calcium levels decreased within 48-96 h. 1,25-dihydroxyvitamin D levels normalized with resolution of the skin lesions. No persistent nephrocalcinosis was observed. CONCLUSION: Pamidronate is effective, well-tolerated in the short-term and obviates the need for prolonged treatment with furosemide and corticosteroids. To prevent nephrocalcinosis, pamidronate might be considered as first line treatment for severe hypercalcemia in SCFN.     

Congenital Craniopharyngioma and Hypercalcemia Induced by Parathyroid Hormone-Related Protein

ObjectiveTo report a case of congenital craniopharyngioma and parathyroid hormone-related protein (PTHrP)-associated humoral hypercalcemia.MethodsDetails of this unusual case are reviewed, from detection of fetal hydrocephalus and a brain tumor, through cesarean delivery at 36 weeks of gestation, to subsequent laboratory studies, management, and confirmation of the diagnosis.ResultsAlthough PTHrP has been well documented as a cause of humoral hypercalcemia of malignancy (HHM) in adult patients with cancer, HHM is uncommon in children. In addition, HHM has rarely been ascribed to nonmalignant tumors. To the best of our knowledge, we report the first case of a neonate with congenital craniopharyngioma and refractory hypercalcemia (peak ionized calcium level of 1.92 mmol/L; normal, 1.05 to 1.3) attributed to an elevated PTHrP value of 8.6 pmol/L (normal, less than 4.7). Intact parathyroid hormone was appropriately undetectable (less than 10 pg/mL; normal, 15 to 65). Despite calcitonin treatment, the hypercalcemia persisted. Although pamidronate infusion stabilized the serum calcium level, the baby did not survive.ConclusionThe diagnosis of craniopharyngioma was confirmed at autopsy, and immunohistochemical studies substantiated that the craniopharyngioma produced PTHrP. (Endocr Pract. 2007;13:67-71)     

Albumin-Corrected Calcium and the Prevalence and Categories of Hypercalcemia in Hospitalized Patients With 1-Year Follow-Up of Undiagnosed Cases

ObjectiveTo assess the impact of using corrected calcium versus total calcium on hypercalcemia case detection in hospitalized patients.MethodsPatients hospitalized from June 2012 to June 2017 with a corrected calcium level of ≥10.5 mg/dL were identified by medical record review. One-year follow-up data through June 2018 were acquired. Albumin-corrected calcium level was calculated: (4 − albumin concentration in g/dL) × 0.8 + total serum calcium in mg/dL.ResultsA group of 1067 patients had a corrected calcium level of ≥10.5 mg/dL. The prevalence of hypercalcemia was 0.73% with total calcium and 1.09% with corrected calcium, respectively, with a 49% relative increase. Most patients (62%) had mild hypercalcemia (10.5-11.9 mg/dL); 3.7% had severe hypercalcemia (>14 mg/dL). With corrected calcium, the most common categories of hypercalcemia were malignancy (35.4%), hypercalcemia that was not further evaluated (31.1%), and hyperparathyroidism (22.4%). All patients in the unidentified category had albumin levels <2.8 g/dL. At the 1-year follow–up, 63% of the unidentified cases had normal calcium levels, and 26.8% had mild persistent hypercalcemia. Of those with persisting hypercalcemia at 1 year, 16.8% were diagnosed with hyperparathyroidism.ConclusionUsing albumin-corrected calcium resulted in an ∼50% increase in the detection of hypercalcemia cases. Although hypercalcemia resolved in majority of the undiagnosed cases at 1 year, a number of these remained abnormal. Detecting hypercalcemic disorders by correcting for low albumin level can help identify conditions such as hyperparathyroidism. Adding auto-calculated albumin-corrected calcium to routine laboratory tests could be a cost-effective intervention to improve the detection of hypercalcemic disorders.     

Splenic Sarcoidosis without Focal Nodularity: A Case of 1,25-Dihydroxyvitamin D-Mediated Hypercalcemia Localized with FDG PET/CT

ObjectiveTo report an uncommon cause of 1,25-dihydroxyvitamin D (1,25[OH]₂D)-mediated hypercalcemia associated with splenic sarcoidosis and illustrate the evaluation and potential role of fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in such patients.MethodsWe present detailed clinical features, laboratory results, imaging results, and pathology results for this rare entity, discuss evaluation and management options, and review previous literature.ResultsA 65-year-old male presented with symptomatic hypercalcemia, with a serum calcium level of 14.1 mg/dL 3 months after being initiated on ergocalciferol for vitamin D deficiency. He was found to have a suppressed parathyroid hormone level, normal 25-hydroxyvitamin D (25[OH]D) level, and elevated 1,25(OH)₂D level. Extensive evaluation did not yield a definitive diagnosis. Hiscalcium levels normalized and symptoms resolved on prednisone then recurred when prednisone was discontinued. FDG PET/CT showed intense uptake in the spleen. Splenectomy was performed, which resulted in resolution of hypercalcemia and yielded a diagnosis of splenic sarcoidosis.Conclusion:Splenic sarcoidosis causing hypercalcemia has been rarely reported. Our case is unique in that the spleen lacked typical focal nodularity on cross-sectional CT imaging, which is expected in sarcoid involvement of the spleen. Our case adds to an emerging literature documenting the potential value of FDG PET/CT in localizing otherwise occult 1,25(OH)₂D-mediated hypercalcemia. (Endocr Pract. 2014;20:e28-e33)     

Humoral Hypercalcemia of Malignancy in a Patient with Large Cell Carcinoma of the Lung: Report of Case and Review of Literature

ObjectiveTo report a case of hypercalcemia associated with parathyroid hormone-related protein (PTHrP) in large cell carcinoma of the lung.MethodsWe present a case of PTHrP-mediated hypercalcemia in a patient with a large cell carcinoma of the lung and review the related literature.ResultsA 43-year-old African American man required medical attention because of lethargy, confusion, and poor oral intake. He had bullous emphysema attributable to a 50-pack-year smoking history. On physical examination, vital signs were normal, he was oriented to place and person but not time, and he had cachexia. Breath sounds were decreased in the left lower lung field. Findings on cardiac and abdominal examination were normal. Results of laboratory studies (and corresponding reference ranges) were as follows: calcium 12.1 mg/dL (8.5 to 10.5), albumin 2.0 g/dL (3.5 to 5.0), phosphorus 2 mg/dL (2.5 to 4.5), alkaline phosphatase 68 U/L (40 to 150), intact parathyroid hormone 5 pg/mL (10 to 60), PTHrP 7.0 pmol/L (0.0 to 1.5), 1,25-dihydroxyvitamin D 20.8 pg/mL (25.1 to 66.1), and 25-hydroxyvitamin D 3.7 ng/mL (10 to 60). Computed tomographic scans of the chest showed a large complex lesion in the left lower hemithorax, a small right pleural effusion, and extensive pulmonary emphysema bilaterally. Open lung biopsy revealed a large cell undifferentiated carcinoma. Abdominal and pelvic computed tomographic scans showed no evidence of metastatic involvement. A bone scan was negative for osseous metastatic lesions.ConclusionAlthough the finding is rare, patients with large cell carcinoma of the lung and hypercalcemia may have humoral hypercalcemia mediated by PTHrP. (Endocr Pract. 2007;13:389-395)     

Acid neutralization capacity of Canadian antacid formulations

A study was designed to determine the acid neutralization capacities (ANCs) of the new Canadian antacid formulations and to compare these products with standard antacid products in terms of lot-to-lot consistency, ANC, sodium and “calorie” contents, and price to the pharmacist. Twenty-three liquid and 18 tablet antacids were tested. The concentrated liquid antacids (Mylanta-2 Extra Strength, Amphojel 500, Gelusil Extra Strength, Maalox TC and Diovol Ex) were found to have the highest ANCs. Six of the tablet antacids (Amphojel, Amphojel Plus, Camalox, Gelusil-400, Maalox and Mylanta-2) were found to have greater ANCs than 15 of the liquid antacids. Between-lot variation exceeded that of within-lot variation in 10 of the 14 liquid antacids for which this variation could be tested. The concentrated liquid antacids provide the highest ANCs with the lowest dosage volume and sodium and calorie contents. Some tablet antacids have the potential to be used as alternatives to liquid antacids because of their high ANC and patient convenience. The inclusion of ANC on the labels of antacid products would assist in the rational determination of the dose of these products.     

Identification of a novel 17,000-dalton parathyroid hormone-like adenylate cyclase-stimulating protein from a tumor associated with humoral hypercalcemia of malignancy

Humoral hypercalcemia of malignancy is a common paraneoplastic syndrome which is characterized by hypercalcemia resulting from secretion by tumors of a circulating bone-resorbing factor. Evidence suggests that in many instances this factor is an adenylate cyclase-stimulating protein which shares features with, but is distinct from, parathyroid hormone (PTH). The current report describes the purification to homogeneity from a humoral hypercalcemia of malignancy-associated tumor of a novel, basic, highly potent PTH-like adenylate cyclase-stimulating protein. This factor differs from previously described PTH-like factors with respect to size, amino acid composition, and specific activity.     

Hypercalcemia in cancer.

Hypercalcemia may occur as a complication of haematological malignancies, in association with solid tumors with bone metastases, and with solid tumors in the absence of bone metastases. The latter syndrome, known as the humoral hypercalcemia of malignancy (HHM) shares many features with primary hyperparathyroidism. A parathyroid hormone-related protein (PTHrP) has been identified, isolated and cloned, which is most likely responsible for the calcium disturbances in HHM, PTHrP is a previously unrecognized hormone which has limited amino-terminal sequence homology with PTH and is the product of a separate gene. Tissue localization studies have identified PTHrP in squamous cell carcinomata, renal cortical carcinomata, in a proportion of breast cancers and in adult T-cell leukemia/lymphoma. In normal tissues, PTHrP has been immunohistochemically localized in keratinocytes, placenta and fetal parathyroid glands. In addition to its role in mediating hypercalcemia in cancer, PTHrP is likely to have an important endocrine role in the fetus, and perhaps a paracrine function in several organs.     

Osteolytic skull metastasis with dural involvement from a papillary thyroid carcinoma

Skull metastatic tumors are relatively rare medical entities and originate most often from the lungs, breast or prostate. We report a case of a 76-year-old woman who presented with a bulging, well-circumscribed mass on the right side of the forehead. Neuroimaging of the cranium detected an osteolytic lesion measuring 7 cm in the largest diameter while propagating outwards and intracranially. A thorough medical history revealed that patient had undergone surgery for invasive breast ductal carcinoma and also for a well-differentiated thyroid carcinoma 13 years ago. Considering patients medical history metastatic breast carcinoma was suspected. After a frontal craniotomy the tumour tissue was totally resected. Histological examination revealed metastatic papillary carcinoma characterized by ground-glass nuclei with intranuclear pseudo inclusion and nuclear grooves. We report clinical and neuroradiological features of this uncommon lesion and discussed the differential diagnosis of skull osteolytic lesion together with the treatment management.     

Chylothorax as a possible diagnostic pitfall: a report of 2 cases with cytologic findings

BACKGROUND: Chyothorax is an uncommon medical condition. To the best of our knowledge, there have been no detailed English-language report dealing with its cytopathologic findings and diagnostic pitfalls CASES: A 12-year-old boy, hemodialysis dependent, with congenital nephrotic syndrome due to focal segmental glomerular sclerosis and a failed renal transplant, developed shortness of breath. Physical and radiologic examinations revealed a left pleural effusion. A 7-year-old boy developed shortness of breath, with a subsequent finding of a left pleural effusion. Multiple osteolytic skeletal lesions were found in this patient. Both patients underwent thoracocentesis. Cytologically, both fluids contained many relatively uniform, large lymphoid cells with high nuclear/cytoplasmic (N/C) ratio, condensed chromatin and occasional nucleoli, resembling blasts. Some nuclei were convoluted. Mitotic figures were present. Foamy macrophages were present in both cases. The differential diagnosis of these populations of cells included a lymphoproliferative disorder. However, the mature T-lymphocytic nature of the cells was confirmed by immunohistochemistry performed on cell block preparations, confirming the clinical impression of chylothorax in both cases. The first patient had chylothorax as a result of trauma due to therapeutic interventions (subclavian vein cannulation), in the second patient the chylothorax was a part of Gorham-Stout syndrome. CONCLUSION: The large T-lymphocytes that are the major cellular component of chylothorax may arouse suspicion of a lymphoproliferative disorder. Attention to the clinical history and immunophenotyping confirm the benign nature of the pleural space fluid. Also, abundant foamy macrophages can be considered a low-power clue to this diagnosis.     

Carotidynia: a cause of neck and face pain.

Carotidynia is a form of vascular neck are face pain in which the vascular change occurs in the carotid artery in the neck. The disorder is not uncommon, and most patients have a prior history of migraine. They present with pain in the neck and face, and are often thought to have a disorder such as chronic sinusitis or trigeminal neuralgia. Diagnosis can be made from the type and location of the pain and the finding of a tender and swollen carotid artery on the same side. Carotidynia responds to the prophylactic medications used for migraine, often disappearing in weeks or months. In some patients the syndrome may become recurrent or chronic, with a variable response to medication.     

Parathyroid hormone-related peptide mediates hypercalcemia in an islet cell tumor of the pancreas.

Hypercalcemia occurring in a patient with an islet cell carcinoma of the pancreas suggests the diagnosis of Multiple Endocrine Neoplasia Type I and associated hyperparathyroidism. We describe a patient with an islet cell carcinoma and hypercalcemia in whom low concentrations of PTH, the absence of skeletal metastases, hypophosphatemia, and elevated nephrogenous cAMP alternatively suggested the syndrome of humoral hypercalcemia of malignancy. The peptide PTHrP was measured in the patient's serum during the course of therapy by an immunoradiometric assay directed toward the midportion of the molecule. Hypercalcemia was treated with an investigational aminobisphosphonate. The concentration of PTHrP[56-86] increased over time and fell after the patient received chemotherapy directed toward the islet cell tumor.     

Fixations extra-osseuses inhabituelles de diphosphonates technétiés dans un cas de cancer bronchique

Visceral uptake of radiobiphosphonates on bone scan is infrequent. A 53-year-old man, with untreated left lung cancer was referred to our department for a bone scan. The bone scan showed a bone metastasis at the right humeral shaft, and uncommon visceral uptake throughout the gastric wall, the liver and the right lung parenchyma. The serum biochemistry revealed a malignant hypercalcemia. Thus, the incidental observation of metastatic calcifications on bone scintigraphy should alert the physician, and lead to an etiological investigation to search an unknown calcium metabolism disturbances requiring emergency treatment.     

Hypercalcemia Secondary to Gastrointestinal Stromal Tumors: Parathyroid Hormone-Related Protein Independent Mechanism?

ObjectiveHypercalcemia is a common paraneoplastic manifestation of many malignancies like breast, ovarian, and squamous-cell cancers of head and neck; however, there have been only a few case reports of hypercalcemia associated with gastrointestinal stromal tumors (GISTs). We report a case of GIST presenting with hypercalcemia without any osseous metastasis and provide a literature review regarding the mechanisms of hypercalcemia and therapeutic strategies.MethodsWe present a report of case and a review of the relevant literature.ResultsA 52-year-old woman with history of localized breast cancer in remission and a pelvic 13 × 12 cm GIST with peritoneal, liver, and lung metastases presented with hypercalcemia of 14.3 mg/dL (8.5-10.5 mg/dL). Parathyroid hormone-related protein (PTHrP) was undetectable, intact parathyroid hormone (PTH) was appropriately low at 1 pg/mL (10-65 pg/mL), and 1,25 dihydroxy vitamin D (1,25 OH₂ vit D) was elevated at 131 pg/mL (18-78 pg/mL) with normal renal function. Calcium responded transiently to tyrosine kinase inhibitor therapy and bisphosphonates but within a year, she expired due to tumor progression.ConclusionGIST is a rare cause of hypercalcemia. In addition to PTHrP expression, direct tumor production of 1,25(OH)₂ vit D or 1-α hydroxylase enzyme resulting in activation of 25-hydroxy vitamin D may be an alternative mechanism in GIST-related hypercalcemia. Therapy with tyrosine kinase inhibitors and bisphosphonates is recommended, though prognosis is poor. Further investigations are needed to characterize the etiology and management of hypercalcemia in these patients. (Endocr. Pract. 2013;19: e158-e162)     

Maculopathy induced by nicotinic acid

Nicotinic acid is a commonly used oral medication for the treatment of hyperlipidemia. Numerous systemic and ocular adverse effects have been reported. Cystoid macular edema, although uncommon, has been reported and resolves upon cessation of the medication. What makes this maculopathy unusual is the absence of leakage on fluorescein angiography. A 47-year-old white male presented with the complaint of blurred vision OU for several months. The patient had an extensive medical history, including hyperlipidemia, for which he was taking nicotinic acid. Bilateral cystoid macular edema was diagnosed. Nicotinic acid was discontinued and the patient's vision returned to 20/20 after 2 months.     

Parathyroid Hormone- Related Protein:An Unusual Mechanism for Hypercalcemia in Sarcoidosis

ObjectiveTo describe parathyroid hormonerelated protein (PTHrP) as a mediator of hypercalcemia in sarcoidosis.MethodsWe present a detailed case report including history, physical, laboratory testing, pathology findings, and followup data over 2 years. We also propose a possible mechanism for PTHrPmediated hypercalcemia in sarcoidosis.ResultsA 56yearold man presented with abdominal pain, fatigue, and excess thirst. Routine laboratory testing demonstrated severe hypercalcemia. The patient was admitted for treatment and workup. Inpatient workup was significant for suppressed parathyroid hormone, low 25- hydroxyvitamin D, normal 1, 25- dihydroxyvitamin D, and elevated PTHrP. The patient was treated for hypercalcemia and discharged for followup. Malignancy screening included computed tomography of the chest, which revealed parenchymal nodules and diffuse lymphadenopathy. Biopsy revealed nonnecrotizing granulomatous sinflammation with positive PTHrP staining by immunohistochemistry. After treatment with intravenous hydration and glucocorticoids, the hypercalcemia resolved and on subsequent followup, PTHrP levels had normalized to 0.5 pmol/L.ConclusionPTHrP may be a possible mediator of hypercalcemia in sarcoidosis. The differential diagnosis of PTHrP- induced hypercalcemia should include sarcoidosis, and further research is needed to establish the incidence and source of PTHrP in sarcoidosis. (Endocr Pract. 2011;17:e84- e86)