Denosumab can be used successfully as a bridge to surgery in patients with severe hypercalcemia due to primary hyperparathyroidism

SUMMARY Severe hypercalcemia is a medical emergency that requires immediate and aggressive management. Primary hyperparathyroidism (PHPT) often causes severe hypercalcemia. Volume resuscitation, parenteral salmon calcitonin, and administration of intravenous bisphosphonates are common measures used to stabilize patients. However, the use of these measures is inadequate in several patients and may even be contraindicated in individuals with renal insufficiency or severe systemic illness. This study demonstrated the efficacy and safety of denosumab in patients with severe hypercalcemia due to PHPT, when immediate surgery was not feasible. We present four patients with severe hypercalcemia due to PHPT. Immediate surgery was not feasible because the patients had severe systemic illness, such as seizures and altered sensorium (case 1); acute severe pancreatitis (cases 2 and 3); or coronavirus disease 2019 pneumonia (case 4). Intravenous normal saline and parenteral salmon calcitonin were inadequate for controlling hypercalcemia. Intravenous bisphosphonates were avoided because of severe systemic illness in all cases and impaired renal function in three cases. Denosumab was administered to control hypercalcemia and allow the stabilization of patients for definitive surgical management. Following denosumab administration, serum calcium levels normalized, and general condition improved in all patients. Three patients underwent parathyroidectomy after two weeks and another patient after eight weeks. The use of denosumab for the management of severe hypercalcemia due to PHPT is efficacious and safe in patients when immediate surgical management is not feasible due to severe systemic illness.

Recomendaciones para el manejo de la lisis tumoral / Recommendations for tumor lysis syndrome management

El síndrome de lisis tumoral representa una complicación potencialmente letal provocada por la liberación masiva de ácidos nucleicos, potasio y fosfato hacia la circulación como resultado de la lisis de células neoplásicas, las cuales se caracterizan por una rápida capacidad de proliferación y alta sensibilidad a fármacos. Esto puede ocurrir de forma espontánea antes del inicio del tratamiento y agravarse luego de haberse iniciado la quimioterapia. Presenta una alta mortalidad. Su prevención continúa siendo la medida terapéutica más importante. El cuadro clínico se caracteriza por la existencia de trastornos del metabolismo hidroelectrolítico, en particular, hipercalemia, hiperfosfatemia e hiperuricemia y por la aparición de una lesión renal aguda. Una adecuada intervención terapéutica implica hidratación intravenosa y medidas para prevenir o corregir las alteraciones metabólicas. En este artículo, se proponen lineamientos para seguir tanto en la etapa diagnóstica como en el tratamiento de esta complicación.

The tumor lysis syndrome represents a potentially lethal complication caused by the massive release of nucleic acids, potassium and phosphate into the circulation as a result of the lysis of neoplastic cells, which are characterized by a rapid proliferation capacity and high sensitivity to drugs. This may occur spontaneously prior to the start of treatment, becoming worse after the initiation of chemotherapy. It presents a high mortality; its prevention continues being the most important therapeutic measure. The clinical picture is characterized by the existence of hydroelectrolytic metabolism disorders, in particular hyperkalemia, hyperphosphatemia and hyperuricemia and by the appearance of an acute renal lesion. Adequate therapeutic intervention involves intravenous hydration and measures to prevent or correct metabolic alterations. This article proposes guidelines to follow both in the diagnostic stage and in the treatment of this complication.

The impact of cinacalcet in the mineral metabolism markers of patients on dialysis with severe secondary hyperparathyroidism / Impacto de cinacalcete em marcadores do metabolismo mineral de pacientes em diálise portadores de hiperparatireoidismo secundário grave

Abstract Introduction: Treating secondary hyperparathyroidism (SHPT), a common condition associated with death in patients with chronic kidney disease, is a challenge for nephrologists. Calcimimetics have allowed the introduction of drug therapies no longer based on phosphate binders and active vitamin D. This study aimed to assess the safety and effectiveness of cinacalcet in managing chronic dialysis patients with severe SHPT. Methods: This retrospective study included 26 patients [age: 52 ± 12 years; 55% females; time on dialysis: 54 (4-236) months] on hemodialysis (N = 18) or peritoneal dialysis (N = 8) with severe SHPT (intact parathyroid hormone (iPTH) level > 600 pg/mL) and hyperphosphatemia and/or persistent hypercalcemia treated with cinacalcet. The patients were followed for 12 months. Their serum calcium (Ca), phosphorus (P), alkaline phosphatase (ALP), and iPTH levels were measured at baseline and on days 30, 60, 90, 180, and 365. Results: Patients with hyperphosphatemia (57.7%), hypercalcemia (23%), or both (19.3%) with iPTH > 600 pg/mL were prescribed cinacalcet. At the end of the study, decreases were observed in iPTH (1348 ± 422 vs. 440 ± 210 pg/mL; p < 0.001), Ca (9.5 ± 1.0 vs. 9.1 ± 0.6 mg/dl; p = 0.004), P (6.0 ± 1.3 vs. 4.9 ± 1.1 mg/dl; p < 0.001), and ALP (202 ± 135 vs. 155 ± 109 IU/L; p = 0.006) levels. Adverse events included hypocalcemia (26%) and digestive problems (23%). At the end of the study, 73% of the patients were on active vitamin D and cinacalcet. Three (11.5%) patients on peritoneal dialysis did not respond to therapy with cinacalcet, and their iPTH levels were never below 800 pg/mL. Conclusion: Cinacalcet combined with traditional therapy proved safe and effective and helped manage the mineral metabolism of patients with severe SHPT.

Resumo Introdução: O tratamento do hiperparatireoidismo secundário (HPTs), patologia comum e associada à mortalidade na doença renal crônica, é um desafio para o nefrologista. Advento dos calcimiméticos propiciou terapêutica medicamentosa diferente da usual, baseada em quelantes de fósforo e vitamina D ativa. O objetivo deste estudo foi avaliar segurança e efetividade de cinacalcete no controle do HPTs grave de pacientes em diálise crônica. Métodos: Estudo retrospectivo 26 pacientes [idade: 52 ± 12 anos; 55% mulheres; tempo em diálise: 54 (4-236) meses], em hemodiálise (N = 18) ou diálise peritoneal (N = 8), com HPTs grave (nível de paratormônio intacto (PTHi) > 600 pg/mL), com hiperfosfatemia e/ou hipercalcemia persistentes, em tratamento com cinacalcete. Período de seguimento de 12 meses. Avaliados níveis séricos de cálcio (Ca), fósforo (P), fosfatase alcalina (FA) e PTHi no início do seguimento, 30, 60, 90, 180 e 365 dias. Resultados: Indicações para início do cinacalcete: hiperfosfatemia (57,7%), hipercalcemia (23%), ou ambos (19,3%) com PTH > 600 pg/mL. Ao final do seguimento, observada redução dos níveis PTHi (1348 ± 422 vs. 440 ± 210 pg/mL; p < 0,001), Ca (9,5 ± 1,0 vs. 9,1 ± 0,6 mg/dl; p = 0,004), P (6,0 ± 1,3 vs. 4,9 ± 1,1 mg/dl; p < 0,001) e FA (202 ± 135 vs. 155 ± 109 UI/L; p = 0,006). Eventos adversos: hipocalcemia (26%) e queixas digestivas (23%). No fim do estudo, 73% pacientes utilizavam vitamina D ativada associada ao cinacalcete. Três (11,5%) pacientes, todos em DP, não responderam ao cinacalcete, mantendo níveis PTHi > 800 pg/mL. Conclusão: Utilização de cinacalcete, associado à terapia tradicional, em pacientes com HPTs grave foi segura, eficiente e associada a melhor controle do metabolismo mineral.

Humoral hypercalcemia of pregnancy treated with bisphosphonates

SUMMARY Hypercalcemia can be hazardous during pregnancy, most cases being due to primary hyperparathyroidism. We report a case of hypercalcemia with suppressed PTH levels necessitating treatment with bisphosphonates during pregnancy. A 38-year-old woman at the 26th week gestation was admitted because of symptomatic hypercalcemia. She did not take any medication that could influence her calcium levels. Physical examination was unremarkable. Laboratory tests on admission were: calcium 12.7 mg/dL (8.5-10.5 mg/dL), phosphorus 1.8 mg/dL (2.5-4.5 mg/dL) and PTH on 3 consecutive tests 1.2, 1.3 and 1.2 pg/mL (15-65 pg/mL). Her 24h urine calcium was 900 mg, 25-OH-D 40 ng/mL (30-58 ng/mL) and 1,25-OH-D 99 pg/mL (80-146 for women in the third trimester). Abdominal ultrasound revealed multiple hypervascular liver lesions consistent with hemangiomas by MRI. Breast and neck ultrasound were normal, and chest CT revealed few non-significant 0.3-0.7 cm pulmonary nodules with no change after an interval of 3 months. She was treated with isotonic saline, loop diuretics and calcitonin. Despite this treatment, calcium levels remained high (14.1 mg/dL), and pamidronate was initiated. On 35th week gestation, she underwent a cesarean section complicated by hypocalcemia of the newborn. Eight weeks after delivery, her calcium levels are 9.4 mg/dL and PTH 18 mg/dL. According to the extensive workup and the post-partum normalization of PTH and calcium levels, we conclude that excessive secretion of placental PTHrP was the cause of hypercalcemia in this patient. No significant adverse effect of bisphosphonate on the mother or baby were seen at the short term follow up.

Crisis hipercalcémica causada por adenoma paratiroideo: reporte de un caso clínico / Hypercalcemic crisis due to parathyroid adenoma: report of a clinical case

La hipercalcemia es un trastorno común que representa aproximadamente el 0,6% de todas las admisiones médicas agudas. El hiperparatiroidismo primario (HPTP) y las neoplasias malignas son las dos causas más comunes de elevación de los niveles séricos de calcio; constituyen, en conjunto, alrededor del 90% de todos los casos. La presentación sintomática clásica de la hipercalcemia se observa con relativa poca frecuencia en el mundo desarrollado; la presentación más común es la detección asintomática en las pruebas bioquímicas. Sin embargo, en casos raros, el HPTP puede desarrollar hipercalcemia aguda, grave y sintomática, llamada crisis hipercalcémica (CH). Esta condición se asocia a alteraciones profundas en el estado mental y las funciones cardíaca, renal y gastrointestinal en presencia de concentraciones marcadamente elevadas de calcio sérico y paratohormona (PTH). Mientras que algunas elevaciones en el calcio sérico pueden ser bien toleradas, los síntomas de la CH son severos. Si el tratamiento se retrasa, la CH puede provocar la muerte. Describimos el caso de un paciente masculino que ingresa en la unidad de cuidados críticos por una CH secundaria a un HPTP por adenoma paratiroideo. (AU)

Hypercalcaemia is a most common disorder, accounting for approximately 0,6% of all acute medical admissions. Primary hyperparathyroidism (PHPT) and malignancy are the two most common causes of increased serum calcium levels, together accounting for about 90% of all cases. The classical symptomatic presentation of hypercalcaemia is seen relatively rarely in the developed world, the most common presentation being asymptomatic and detected following on biochemical testing. However, in rare cases HPTP can result in acute, severe and symptomatic hypercalcemia, called hypercalcemic crisis (HC). This condition is associated with profound disturbances in mental status, and cardiac, renal, and gastrointestinal function in the presence of markedly increased serum calcium and parathyroid hormone (PTH) concentrations. While some elevations in serum calcium can be well tolerated, symptoms of HC are severe. If treatment is delayed, HC can result in death. We describe herein a case of a male patient who was admitted to the intensive care unit as a consequence of HC resulting from elevated PTH, secondary to a parathyroid adenoma. We describe the case of a male patient who was admitted to the critical care unit for a HC mediated by PTH secondary to a parathyroid adenoma. (AU)

Use of cinacalcet and sunitinib to treat hypercalcaemia due to a pancreatic neuroendocrine tumor

SUMMARY Neuroendocrine tumors (NETs) can secrete hormones, including ectopic secretions, but they have been rarely associated with malignant hypercalcemia. A 52-year-old man with a history of diabetes mellitus was diagnosed with a pancreatic tumor. A pancreatic biopsy confirmed a well-differentiated pancreatic NET (pNET). The patient subsequently developed liver metastasis and hypercalcemia with high 1,25 OH vitamin D and suppressed parathyroid hormone (PTH) levels. Hypercalcemia was refractory to chemotherapy, intravenous saline fluids, diuretics, calcitonin and zoledronate. Cinacalcet administration (120 mg/day) resulted in a significant calcium reduction. Hypocalcemia was observed when sunitinib was added three months later and cinacalcet was stopped. Subsequently, the calcium and PTH levels normalized. After six months, we observed 20% shrinkage of the pancreatic tumor and necrosis of a liver metastasis. Cinacalcet is an allosteric activator of the calcium receptor agonist, and it is used for severe hypercalcemia in patients with primary (benign and malignant) hyperparathyroidism. In this patient, cinacalcet demonstrated a calcium lowering effect, normalized hypophosphatemia, and improved the clinical condition of the patient. The mechanism through which cinacalcet improved PTH-rp mediated hypercalcemia is still unclear, but studies have suggested that a potential mechanism is the activation of calcitonin secretion. Sunitinib is an oral multi-targeted tyrosine kinase inhibitor used to treat advanced pNETs. The hypocalcemic effects of sunitinib have not been previously described in a patient with pNET. Here, we report for the first time the successful combination of cinacalcet and sunitinib in the treatment of a pNET patient presenting with malignant hypercalcemia.

Hipercalcemia hipocalciurica familiar en una paciente con mutación del receptor de calcio: forma atípica de presentación y tratamiento con cinacalcet / Familial hypocalciuric hypercalcemia in a patient with calcium-sensing receptor mutation: atypical clinical presentation and treatment with cinacalcet

El hiperparatiroidismo familiar y la hipercalcemia hipocalciúrica familiar (HHF) constituyen un subgrupo heterogéneo de trastornos con herencia mendeliana, que representan en conjunto el 5% de las causas de hipercalcemia PTH dependiente. La HHF se asocia con mutaciones del gen del receptor sensor de calcio (CaSR). Esta entidad se manifiesta, en la mayoría de los casos, con la presentación asintomática y familiar de hipercalcemia e hipocalciuria y valores elevados o normales de hormona paratiroidea (PTH). Los avances en la biología molecular han contribuido al diagnóstico, evaluación del fenotipo de cada entidad y elección del tratamiento. Se describe el caso de una paciente con hipercalcemia estudiada a partir de una tumoración de cuello asociada con una glándula paratiroides quística. Luego de un exhaustivo proceso diagnóstico se halló en el estudio genético una mutación inactivante en el gen CaSR. Teniendo en cuenta la presencia de la relación clearance calcio/clearance creatinina <0,01 y la falta de respuesta al tratamiento quirúrgico, se consideró la entidad de HHF con forma de presentación atípica. La paciente, sin tratamiento, presentaba un progresivo incremento de la calcemia luego de la cirugía de las glándulas paratiroides, que no se controló con el uso de bifosfonatos y evolucionó con episodios de mareos y desmayos frecuentes sin causa neurológica o cardiovascular detectada. Por lo tanto, se inició el tratamiento con cinacalcet, con el cual se obtuvo una buena respuesta terapéutica: descenso de la calcemia y mejoría de la sintomatología luego de un año de su comienzo. El cinacalcet es una herramienta terapéutica de importancia en estos raros casos de HHF. (AU)

Familial hyperparathyroidism including familial hypocalciuric hypercalcemia (FHH) is an heterogeneous subgroup of disorders with Mendelian inheritance, that account for 5% of PTH dependent hypercalcemia. FHH is associated with mutations of the calcium receptor (CaSR) gene. This entity is manifested by hypercalcemia with hypocalciuria and high or normal levels of parathyroid hormone (PTH) generally asymptomatic and with familial presentation. Advances in molecular biology have contributed to the diagnosis, evaluation of the phenotype of each entity and the choice of treatment. We describe a patient with hypercalcemia diagnosed following the finding of a neck tumor associated with cystic parathyroids. After an exhaustive diagnostic process, an inactivating mutation in the CaSR gene was found. Considering the presence of a ratio clearance calcium / clearance creatinine <0.01 and the lack of response to surgical treatment, HHF entity with atypical presentation was considered. The patient exhibited progressive increase in serum calcium following parathyroid surgery, which was not controlled with the use of bisphosphonates and evolved into episodes of frequent dizziness and fainting, without neurological or cardiovascular causes. Treatment with cinacalcet was initiated, with a good therapeutic response. The use of cinacalcet is a useful therapeutic tool in these rare cases of FHH. (AU)

Mycobacterium avium-intracellulare and the unpredictable course of hypercalcemia in an AIDS patient

Abstract A 37-year-old man with AIDS presented with altered mental status four weeks after stopping his medications for Mycobacterium avium-intracellulare (MAI). He had low CD4 cell count and severe hypercalcemia. Bone marrow biopsy revealed bone marrow infiltration by granulomas positive for acid-fast bacilli and cultures grew MAI. His hypercalcemia continued to worsen with the initiation of MAI therapy but we were able to treat it successfully with pamidronate and calcitonin.

Rare association between penile squamous cell carcinoma and parathyroid related peptide (PTH-rP) secretion / Associação rara entre carcinoma de células escamosas do pênis e secreção de peptídeo relacionado ao paratormônio (PTH-rP)

We report on a rare case of an adult with severe hypercalcemia secondary to the ectopic secretion of parathyroid-related peptide (PTH-rP) from a penile squamous cell cancer (PC). A patient of 47 years old was admitted with warty lesions and areas of ulceration covered by purulent material in a large area of the groin, scrotum and penis. Laboratory tests revealed severe hypercalcemia and elevation of PTH-rP; the biopsy reported PC. Hypercalcemia was successfully treated with zoledronic acid, however, the tumor displayed aggressive behavior, which resulted in a poor prognosis for the patient.

Relatamos um caso raro em um adulto com hipercalcemia grave secundária à secreção ectópica de peptídeo relacionado ao paratormônio (PTH-rP) de um carcinoma de células escamosas do pênis (CP). Um paciente de 47 anos foi admitido com lesões verrucosas e áreas de ulceração cobertas por material purulento em uma grande área da virilha, escroto e pênis. Os testes laboratoriais revelaram hipercalcemia grave e elevação do PTH-rP; a biópsia mostrou um CP. A hipercalcemia foi tratada de forma bem-sucedida com ácido zoledrônico. Entretanto, o tumor apresentava um comportamento agressivo, resultando em um prognóstico ruim para o paciente.

Response of enuretic children with and without hypercalciuria to nasal desmopressin

Nocturnal enuresis is a common diagnosis in patients referred to pediatric and pediatric nephrology clinics. Nocturnal polyuria is an important patho-physiologic factor in enuresis. Hypercalciuria, with altering concentrating capacity of the kidneys, can affect children's response to desmopressin. This is a double blind clinical trial starting September 2007 to March 2008. One hundred and twenty four enuretic children, 76 [61.3%] males, 48 [38.7%] females, mean age 7.7 [ +/- 1.7], were evaluated by measuring random morning urinary calcium to creatinine ratio. Patients were divided into group 1 with a calcium to creatinine ratio equal to or more than 0.2 mg/mg, and group 2 with a ratio less than 0.2 [Hypercalciuric and non hypercalciuric respectively]. All patients received 10 to 40 mcg of nasal desmopressin at bed time. The response was defined as reduction in wet nights, a "full response" [greater than 90% reduction], "partial response" [50% to 90% reduction] and "no response" [less than 50% reduction]. Chi-square method was used to compare the responses and P<0.05 was considered statistically significant. Nineteen patients in group 1 [Hypercalciuric] and 105 patients in group 2 [Non hypercalciuric] were studied. Response to desmopressin was "full" in 47.4% in group 1 and 64.8% in group 2. 42.1% and 26.7% had "Partial response" in group1 and 2 respectively [P < 0.04]. Hypercalciuria can affect negatively the responsiveness to desmopressin therapy

Ethanol injection under ultrasound guidance to palliate unresectable parathyroid carcinoma / Injeção percutânea de etanol guiada por ultra-sonografia para paliação de carcinoma de paratireóide não-extirpável

BACKGROUND: Severe hypercalcemia is the leading cause of death in patients with parathyroid carcinoma. Non-curative resection and pharmacological measures may be useful for palliation in cases with recurrent and metastatic disease. Palliative treatment with intra-neoplastic ethanol injection has not been reported yet. METHODS: Ultrasound-guided percutaneous alcohol injection in one patient with unresectable parathyroid carcinoma is reported. RESULTS: One male patient with extensive recurrent parathyroid carcinoma suffering from severe hypercalcemia, refractory to all available medical measures has undergone two percutaneous ethanol injections. No major complications ensued and parathormone levels decreased from 2,990 pg/mL to 2,230pg/ml after the first injection, and to 1,104pg/mL after the second one. Calcium levels decreased from 19.8 mg/dL to 16.1 mg/dL and to 14.5 mg/dL, respectively. The patient died of metabolic hypercalcemia complications about two months later, probably due to mediastinal disease progression. CONCLUSION: Ultrasound-guided percutaneous ethanol injection may be employed to palliate parathyroid carcinoma in selected cases, with a transitory decrease in PTH and calcium levels.

INTRODUÇÃO: A hipercalcemia severa é a principal causa de óbito nos pacientes com carcinoma de paratireóide. Em casos com recidiva ou doença metastática inoperáveis, a ressecção não curativa e as medidas farmacológicas podem ser úteis para a paliação. O presente estudo relata a experiência com a injeção de etanol na neoplasia para tratamento paliativo em um caso. MÉTODO: Relato da injeção percutânea de etanol em paciente com carcinoma de paratireóide recidivado, não passível de ressecção. RESULTADO: Paciente masculino com hipercalcemia refratária a tratamento clínico decorrente de recidiva local não extirpável de carcinoma de paratireóide. Submetido a duas sessões de injeção percutânea de etanol. Não houve complicações maiores. Após a primeira injeção, o nível de paratormônio reduziu-se de 2.990 pg/mL para 2.230 pg/ml. Após a segunda injeção, o nível caiu para 1.104 pg/mL. A calcemia declinou de 19,8 mg/dL para 16,1 mg/dL e 14,5 mg/dL, respectivamente. O paciente faleceu de complicação metabólica, cerca de dois meses depois, possivelmente pela progressão da doença no mediastino. CONCLUSÃO: A injeção percutânea de etanol pode ser utilizada para paliação do carcinoma de paratireóide em casos selecionados, com queda transitória do nível de hormônio da paratireóide e da calcemia.

Osteonecrose bilateral na maxila induzida por zolendronato / Zoledronate-induced maxillary bilateral osteonecrosis

Os bifosfonatos são drogas utilizadas com diversas finalidades, dentre elas, o tratamento da hipercalcemia secundária a neoplasias malignas. Embora sua eficácia médica seja comprovada, o número de pacientes que apresentam osteonecrose nos maxilares vem aumentando devido ao uso desse medicamento. Este relato mostra o tratamento de um paciente que desenvolveu osteonecrose de maxila após fazer uso crônico de bifosfonato, enfatizando o surgimento de lesões maxilares agressivas concomitantes à piora do estado geral do paciente.

Bisphosphonates are drugs used to treat malignat hypercalcemia in certain types of cancer. Although this drug has clear evidence of medical efficacy, there are an increasing number of patients that develop bisphosphonate associated osteonecrosis of the jaws. This report show the treatment of a patient that present osteonecrosis subsequent the cronic use of bisphosphonate showing a strong correlation between the aggressive aspect of the lesion and general health patient.

Tratamento da doença de Paget óssea: importância do ácido zoledrônico / Treatment of Paget's disease of bone: importance of the zoledronic acid / Treatment of Paget's disease of bone: importance of the zoledronic acid

A doença de Paget é uma doença esquelética, de distribuição monostótica ou poliostótica, podendo ser causada por uma infecção viral e/ou fatores genéticos. É caracterizada por um aumento da remodelação óssea, resultando em anormalidade da arquitetura óssea. A excessiva reabsorção óssea osteoclástica, seguida secundariamente de aumento da atividade osteoblástica, leva à substituição do osso normal por osso desorganizado, aumentado, e com estrutura enfraquecida, propensa a deformidades e fraturas. A doença de Paget pode ser diagnosticada através de exames radiológicos, cintilografia e exames bioquímicos. O objetivo primário do tratamento é reduzir a dor e o risco do aparecimento das complicações a longo prazo. Atualmente dispõe-se de drogas anti-reabsortivas potentes, as quais controlam a reabsorção óssea e proporcionam uma grande melhora no tratamento. O ácido zoledrônico, um bisfosfonato de última geração, tem a vantagem de maior potência e remissão mais prolongada, além de um tempo de infusão curto.

Paget's disease is a localised monostotic or polyostotic bone disease of unknown origin. It may be caused by a slow viral infection and/or genetic factors. It is characterised by increased bone remodelling and an initially excessive osteoclastic bone resorption, followed by a secondary increase in osteoblastic activity, leading to replacement of the normal bone by a disorganized, enlarged, and weakened osseous structure prone to deformities and fractures. The disease may be diagnosed by radiography, scintigraphy and biochemical tests. The primary aim of treatment is to reduce pain and risk of developing long-term complications. Potent antiresorptive drugs are now available, which control the increased bone remodelling and have led to a dramatic improvement in treatment. Zoledronic acid, a new generation of bisphosphonates, has the advantage of great potency and long duration of remission and a short infusion time.

Parathyroid carcinoma: difficult management options.

Parathyroid carcinoma is a rare cause of primary hyperparathyroidism and these tumours are usually hyperfunctional as opposed to other malignant endocrine tumors. Surgery is the only effective treatment while nonsurgical modalities yield poor results. We report a patient, who presented with palpable mass in the neck and severe hypercalcemia. He underwent debulking surgery and received allendronate, calcitonin, dacarbazine followed by in- situ alcohol instillation with some success.

Extracellular calcium-sensing receptor: structural and functional features and association with diseases

The recently cloned extracellular calcium-sensing receptor (CaR) is a G protein-coupled receptor that plays an essential role in the regulation of extracellular calcium homeostasis. This receptor is expressed in all tissues related to this control (parathyroid glands, thyroid C-cells, kidneys, intestine and bones) and also in tissues with apparently no role in the maintenance of extracellular calcium levels, such as brain, skin and pancreas. The CaR amino acid sequence is compatible with three major domains: a long and hydrophilic aminoterminal extracellular domain, where most of the activating and inactivating mutations described to date are located and where the dimerization process occurs, and the agonist-binding site is located, a hydrophobic transmembrane domain involved in the signal transduction mechanism from the extracellular domain to its respective G protein, and a carboxyterminal intracellular tail, with a well-established role for cell surface CaR expression and for signal transduction. CaR cloning was immediately followed by the association of genetic human diseases with inactivating and activating CaR mutations: familial hypocalciuric hypercalcemia and neonatal severe hyperparathyroidism are caused by CaR-inactivating mutations, whereas autosomal dominant hypoparathyroidism is secondary to CaR-activating mutations. Finally, we will comment on the development of drugs that modulate CaR function by either activating (calcimimetic drugs) or antagonizing it (calcilytic drugs), and on their potential therapeutic implications, such as medical control of specific cases of primary and uremic hyperparathyroidism with calcimimetic drugs and a potential treatment for osteoporosis with a calcilytic drug

use of bisphosphonates in skeletal disease due to breast cancer

The variability of different breast cancers in the susceptibility to metastatic bone disease is poorly understood, but may depend in part upon gene expression of PTHrP and the vitamin D receptor. In contrast, much more is known of the manner which metastatic breast disease affects bone remodelling to induce osteolytic bone disease. Mechanisms include a generalised increase in activation frequency at sites close to metastatic tissue, an imbalance between the amount of bone formed and that resorbed within resorption cavities, and uncoupling of bone formation from bone resorption. The greatest morbidity from metastatic bone disease arises from osteolytic disease and gives rise to hypercalcemia, bone pain and fractures. Since osteolysis is primarily mediated by the activation of osteoclasts, there has been a great deal of interest in the use of agents which primarily affect bone pain and fractures. Since osteolysis is primarily mediated by the activation of osteoclasts, there has been a great deal of interest in the use of agents which primarily affect bone metabolism to alter the natural history of metastatic bone disease. Non-steroidal anti-inflammatory agents and cytotoxic agents are capable of inducing responses in bone, but are limited by their toxicity when effective doses are utillized. The use of calcitonin in the long term suppression of osteolysis has also been disappointing. The bisphosphonates are, however, capable of inducing sustained decreases in osteoclast activity and numbers in patients with osteolytic bone disease. There are now several studies which have examined the effects of the bisphosphonates on skeletal morbidity in breast cancer. Both clodronate and pamidronate decrease the incidence of hypercalcemia, bone pain and pathological fractures, but do not significantly alter mortality. Given, however, the unchanging survival in patients with metastatic bone disease, significant improvements in the quality of remaining life is an important therapeutic effect

Emergências oncológicas mais frequentes na prática clínica / Oncologic emergencies frequency in clinical practice

Os autores fazem uma revisäo bibliográfica, sintetizando de forma clara e concisa os principais aspectos etiológicos e terapêuticos das emergências oncológicas mais frequentemente encontradas na prática clínica diária: hipercalcemia, síndrome da veia cava superior e compressäo medular