Multiple endocrine neoplasia 1 (MEN1) is a rare genetic syndrome characterized by the manifestation of tumors in endocrine glands most often in the parathyroid gland (PG). Treatment may involve several parathyroidectomies (PTX), especially in young patients, which increases the risk of postoperative complications. We present a 16-year-old patient with a family history of MEN1 syndrome. The patient started to show biochemical signs of hyperparathyroidism (HPT) and hypercalcemia at the age of 10. One and a half years later a PTX was successfully performed with removal of the two left PGs. However, a rise in plasma parathyroid hormone and ionized calcium was observed 4 years later. Preoperative noninvasive imaging with 99mTc-sestamibi scintigraphy showed no definitive parathyroid adenoma. A 11C-methionine position emission tomography combined with MRI (MET-PET/MRI) was then performed and detected a focus posterior to the lower part of the right thyroid lobe. Intraoperative angiography with fluorescence and indocyanine green dye was used to assess the vascularization of the remaining PGs. The lower right PG was removed. The patient was discharged with normalized biochemical values and without postoperative complications. Recurrence of primary HPT is frequent in MEN1 patients which often necessitates repeated operations. Our case report showed that the use of advanced noninvasive preoperative imaging techniques and intraoperative fluorescent imaging are valuable tools and should be taken into consideration in selected cases to avoid postoperative complications. To our knowledge, this is the first case where MET-PET/MRI has been used to detect parathyroid pathology.
MEN1 patients will develop parathyroid disease, which eventually will lead to surgical treatment with removal of the pathological glands.
Preoperatively usage of MRI combined with PET tracers such as 11C-methionine and 18F-Fluorocholine are able to detect parathyroid pathology with a higher sensitivity than conventional imaging.
Techniques using intraoperatively angiography with fluorescence and florescent dyes allow surgeons to verify the vascularization of each parathyroid gland.
Optimization of noninvasive preoperative imaging techniques and intraoperative fluorescent imaging are valuable tools and should be taken into consideration when performing PTX consecutively in the same patient to avoid postoperative complications.
A 53-year-old man who used growth hormone (GH), anabolic steroids and testosterone (T) for over 20 years presented with severe constipation and hypercalcaemia. He had benign prostatic hyperplasia and renal stones but no significant family history. Investigations showed – (1) corrected calcium (reference range) 3.66 mmol/L (2.2–2.6), phosphate 1.39 mmol/L (0.80–1.50), and PTH 2 pmol/L (1.6–7.2); (2) urea 21.9 mmol/L (2.5–7.8), creatinine 319 mmol/L (58–110), eGFR 18 mL/min (>90), and urine analysis (protein 4+, glucose 4+, red cells 2+); (3) creatine kinase 7952 U/L (40–320), positive anti Jo-1, and Ro-52 antibodies; (4) vitamin D 46 nmol/L (30–50), vitamin D3 29 pmol/L (55–139), vitamin A 4.65 mmol/L (1.10–2.60), and normal protein electrophoresis; (5) normal CT thorax, abdomen and pelvis and MRI of muscles showed ‘inflammation’, myositis and calcification; (6) biopsy of thigh muscles showed active myositis, chronic myopathic changes and mineral deposition and of the kidneys showed positive CD3 and CD45, focal segmental glomerulosclerosis and hypercalcaemic tubular changes; and (7) echocardiography showed left ventricular hypertrophy (likely medications and myositis contributing), aortic stenosis and an ejection fraction of 44%, and MRI confirmed these with possible right coronary artery disease. Hypercalcaemia was possibly multifactorial – (1) calcium release following myositis, rhabdomyolysis and acute kidney injury; (2) possible primary hyperparathyroidism (a low but detectable PTH); and (3) hypervitaminosis A. He was hydrated and given pamidronate, mycophenolate and prednisolone. Following initial biochemical and clinical improvement, he had multiple subsequent admissions for hypercalcaemia and renal deterioration. He continued taking GH and T despite counselling but died suddenly of a myocardial infarction.
The differential diagnosis of hypercalcaemia is sometimes a challenge.
Diagnosis may require multidisciplinary expertise and multiple and invasive investigations.
There may be several disparate causes for hypercalcaemia, although one usually predominates.
Maintaining ‘body image’ even with the use of harmful drugs may be an overpowering emotion despite counselling about their dangers.
Brown tumors are osteoclastic, benign lesions characterized by fibrotic stroma, intense vascularization and multinucleated giant cells. They are the terminal expression of the bone remodelling process occurring in advanced hyperparathyroidism. Nowadays, due to earlier diagnosis, primary hyperparathyroidism keeps few of the classical manifestations and brown tumors are definitely unexpected. Thus, it may happen that they are misdiagnosed as primary or metastatic bone cancer. Besides bone imaging, endocrine evaluation including measurement of serum parathyroid hormone and calcium (Ca) levels supports the pathologist to address the diagnosis. Herein, a case of multiple large brown tumors misdiagnosed as a non-treatable osteosarcoma is described, with special regards to diagnostic work-up. After selective parathyroidectomy, treatment with denosumab was initiated and a regular follow-up was established. The central role of multidisciplinary approach involving pathologist, endocrinologist and oncologist in the diagnostic and therapeutic work-up is reported. In our opinion, the discussion of this case would be functional especially for clinicians and pathologists not used to the differential diagnosis in uncommon bone disorders.
Brown tumors develop during the remodelling process of bone in advanced and long-lasting primary or secondary hyperparathyroidism.
Although rare, they should be considered during the challenging diagnostic work-up of giant cell lesions.
Coexistence of high parathyroid hormone levels and hypercalcemia in primary hyperparathyroidism is crucial for the diagnosis.
A detailed imaging study includes bone X-ray, bone scintiscan and total body CT; to rule out bone malignancy, evaluation of bone lesion biopsy should include immunostaining for neoplastic markers as H3G34W and Ki67 index.
If primary hyperparathyroidism is confirmed, selective parathyroidectomy is the first-line treatment.
In advanced bone disease, treatment with denosumab should be considered, ensuring a strict control of Ca levels.
Standard treatment of hypoparathyroidism consists of supplementation of calcium and vitamin D analogues, which does not fully restore calcium homeostasis. In some patients, hypoparathyroidism is refractory to standard treatment with persistent low serum calcium levels and associated clinical complications. Here, we report on three patients (58-year-old male, 52-year-old female, and 48-year-old female) suffering from severe treatment-refractory postsurgical hypoparathyroidism. Two patients had persistent hypocalcemia despite oral treatment with up to 4 µg calcitriol and up to 4 g calcium per day necessitating additional i.v. administration of calcium gluconate 2–3 times per week, whereas the third patient presented with high frequencies of hypocalcemic and treatment-associated hypercalcemic episodes. S.c. administration of rhPTH (1–34) twice daily (40 µg/day) or rhPTH (1–84) (100 µg/day) only temporarily increased serum calcium levels but did not lead to long-term stabilization. In all three cases, treatment with rhPTH (1–34) as continuous s.c. infusion via insulin pump was initiated. Normalization of serum calcium and serum phosphate levels was observed within 1 week at daily 1–34 parathyroid hormone doses of 15 µg to 29.4 µg. Oral vitamin D and calcium treatment could be stopped or reduced and regular i.v. calcium administration was no more necessary. Ongoing efficacy of this treatment has been documented for up to 7 years so far. Therefore, we conclude that hypoparathyroidism that is refractory to both conventional treatment and s.c. parathyroid hormone (single or twice daily) may be successfully treated with continuous parathyroid hormone administration via insulin pump.
Standard treatment of hypoparathyroidism still consists of administration of calcium and active vitamin D.
Very few patients with hypoparathyroidism also do not respond sufficiently to standard treatment or administration of s.c. parathyroid hormone once or twice daily.
In those cases, continuous s.c. administration of parathyroid hormone via insulin pump may represent a successful treatment alternative.
Thora Y ChaiDepartment of Endocrinology, Nepean Blue Mountains Local Health District, Kingswood, New South Wales, Australia Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
We report the case of a 65-year-old female who presented with symptomatic hypercalcaemia (corrected calcium of 4.57 mmol/L) with confusion, myalgias and abdominal discomfort. She had a concomitant metabolic alkalosis (pH 7.46, HCO3- 40 mmol/L, pCO2 54.6 mmHg). A history of significant Quick-Eze use (a calcium carbonate based antacid) for abdominal discomfort, for 2 weeks prior to presentation, suggested a diagnosis of milk-alkali syndrome (MAS). Further investigations did not demonstrate malignancy or primary hyperparathyroidism. Following management with i.v. fluid rehydration and a single dose of i.v. bisphosphonate, she developed symptomatic hypocalcaemia requiring oral and parenteral calcium replacement. She was discharged from the hospital with stable biochemistry on follow-up. This case demonstrates the importance of a detailed history in the diagnosis of severe hypercalcaemia, with MAS representing the third most common cause of hypercalcaemia. We discuss its pathophysiology and clinical importance, which can often present with severe hypercalcaemia that can respond precipitously to calcium-lowering therapy.
Milk-alkali syndrome is an often unrecognised cause for hypercalcaemia, but is the third most common cause of admission for hypercalcaemia.
Calcium ingestion leading to MAS can occur at intakes as low as 1.0–1.5 g per day in those with risk factors.
Early recognition of this syndrome can avoid the use of calcium-lowering therapy such as bisphosphonates which can precipitate hypocalcaemia.
Familial hypomagnesemia with secondary hypocalcemia (FHSH) is a rare autosomal recessive disorder (OMIM# 602014) characterized by profound hypomagnesemia associated with hypocalcemia. It is caused by mutations in the gene encoding transient receptor potential cation channel member 6 (TRPM6). It usually presents with neurological symptoms in the first months of life. We report a case of a neonate presenting with recurrent seizures and severe hypomagnesemia. The genetic testing revealed a novel variant in the TRPM6 gene. The patient has been treated with high-dose magnesium supplementation, remaining asymptomatic and without neurological sequelae until adulthood. Early diagnosis and treatment are important to prevent irreversible neurological damage.
Loss-of-function mutations of TRPM6 are associated with FHSH.
FHSH should be considered in any child with refractory hypocalcemic seizures, especially in cases with serum magnesium levels as low as 0.2 mM.
Normocalcemia and relief of clinical symptoms can be assured by administration of high doses of magnesium.
Untreated, the disorder may be fatal or may result in irreversible neurological damage.
Brown tumors (BTs) are expansile osteolytic lesions complicating severe primary hyperparathyroidism (PHPT). Clinical, radiological and histological features of BTs share many similarities with other giant cell-containing lesions of the bone, which can make their diagnosis challenging. We report the case of a 32-year-old man in whom an aggressive osteolytic lesion of the iliac crest was initially diagnosed as a giant cell tumor by biopsy. The patient was scheduled for surgical curettage, with a course of neoadjuvant denosumab. Routine biochemical workup prior to denosumab administration incidentally revealed high serum calcium levels. The patient was diagnosed with PHPT and a parathyroid adenoma was identified. In light of these findings, histological slices of the iliac lesion were reviewed and diagnosis of a BT was confirmed. Follow-up CT-scans performed 2 and 7 months after parathyroidectomy showed regression and re-ossification of the bone lesion. The aim of this case report is to underline the importance of distinguishing BTs from other giant cell-containing lesions of the bone and to highlight the relevance of measuring serum calcium as part of the initial evaluation of osteolytic bone lesions. This can have a major impact on patients’ management and can prevent unnecessary invasive surgical interventions.
Although rare, brown tumors should always be considered in the differential diagnosis of osteolytic giant cell-containing bone lesions.
Among giant cell-containing lesions of the bone, the main differential diagnoses of brown tumors are giant cell tumors and aneurysmal bone cysts.
Clinical, radiological and histological characteristics can be non-discriminating between brown tumors and giant cell tumors. One of the best ways to distinguish these two diagnoses appears to be through biochemical workup.
Differentiating brown tumors from giant cell tumors and aneurysmal bone cysts is crucial in order to ensure better patient care and prevent unnecessary morbid surgical interventions.
A 40-year-old woman was hospitalised at 25-week gestation following a diagnosis of severe symptomatic hypercalcaemia (adjusted serum calcium 3.02 mmol/L). A diagnosis of primary hyperparathyroidism (PHP) was made on the basis of elevated parathyroid hormone (PTH) 11.2 pmol/L (reference range 1.5–6.9) and exclusion of familial hypocalciuric hypercalcaemia. Ultrasound examination of the neck did not convincingly demonstrate an abnormal or enlarged parathyroid gland and parathyroid scintigraphy was not performed due to maternal choice relating to perceived radiation risk to the foetus. At neck exploration during the 28th week of pregnancy a right lower pole parathyroid lesion was excised together with two abnormal lymph nodes (largest 1.6 cm). Histology confirmed a parathyroid adenoma and also papillary thyroid carcinoma deposits in the two resected lymph nodes. Post-operatively, levels of adjusted serum calcium normalised and pregnancy progressed uneventfully to term. Total thyroidectomy was performed 2 weeks after delivery revealing two small foci of papillary micro-carcinoma (largest 2.3 mm, one in each thyroid lobe) with no evidence of further metastatic tumour in lymph nodes removed during functional neck dissection. Radioiodine remnant ablation (RRA) was performed 2 months post thyroidectomy to allow for breast involution. The patient remains in full clinical and biochemical remission 9 years later. We present and review the difficult management decisions faced in relation to the investigation and treatment of PHP in pregnancy, further complicated by incidentally discovered locally metastatic pT1aN1aM0 papillary thyroid carcinoma.
PHP may have serious consequences during pregnancy and usually requires surgical management during pregnancy to reduce the risk of maternal and foetal complications. The indications for and optimal timing of surgical management are discussed.
Localisation by parathyroid scintigraphy is controversial during pregnancy: modified dose regimes may be considered in preference as an alternative to unguided neck exploration.
Breastfeeding is contraindicated for 6–8 weeks before radioactive-iodine remnant ablation (RRA) to prevent increased breast uptake. Breastfeeding is further contra-indicated until after a subsequent pregnancy.
Incidentally discovered differentiated thyroid carcinoma (DTC) in cervical lymph nodes in some cases may be managed expectantly because in one quarter of thyroidectomies the primary tumour remains occult.
Denosumab is a fully human MAB that acts as a potent anti-resorptive by inhibiting activation of osteoclasts by inhibiting the receptor activator of nuclear factor-kappa B (RANK) ligand. Hypocalcaemia has been reported as one of the serious adverse sequelae of use of denosumab. We present a case of refractory hypocalcaemia following administration of a single dose of denosumab in a patient with metastatic castrate-resistant prostate cancer. The patient’s serum calcium and vitamin D concentrations and renal function were normal prior to denosumab administration. Serum alkaline phosphatase (ALP) level was however elevated pre-morbidly consistent with known bone metastases. The patient was treated with high-dose oral and IV calcium without any appreciable response in serum calcium. During his 30-day hospital admission, he demonstrated disease progression with development of new liver metastases and bone marrow involvement. Normocalcaemia was not achieved despite 1 month of aggressive therapy. Given the patient was asymptomatic and prognosis guarded, he was eventually discharged for ongoing supportive care under the palliative care team.
Denosumab is a potent anti-resorptive therapy and hypocalcaemia is one of the known adverse effects.
Serum calcium and vitamin D concentrations must be replete prior to administration of denosumab to reduce the risk of hypocalcaemia.
Denosumab has been proven to be more effective than zoledronic acid in preventing skeletal-related adverse effects in patients with metastatic castrate-resistant prostate cancer.
Creswell J EastmanWestmead Private Hospital, Westmead, Sydney, New South Wales, Australia Westmead Teaching Hospital, Royal North Shore Teaching Hospital, The University of Sydney, Sydney, New South Wales, Australia
Parathyroid-independent hypercalcaemia of pregnancy, due to biallelic loss of function of the P450 enzyme CYP24A1, the principal inactivator of 1,25(OH)2D results in hypervitaminosis D, hypercalcaemia and hypercalciuria. We report two cases of this disorder, with intractable hypercalcaemia, one occurring during gestation and into the postpartum, and the other in the postpartum period. Case 1, a 47-year-old woman with a twin pregnancy conceived by embryo transfer, presented with hypercalcaemia at 23 weeks gestation with subnormal serum parathyroid hormone (PTH) and normal serum 25-OH D levels. She was admitted to hospital at 31 weeks gestation with pregnancy-induced hypertension, gestational diabetes and increasing hypercalcaemia. Caesarean section at 34 weeks gestation delivered two healthy females weighing 2.13 kg and 2.51 kg. At delivery, the patient’s serum calcium level was 2.90 mmol/L. Postpartum severe hypercalcaemia was treated successfully with Denosumab 60 mg SCI, given on two occasions. CYP24A1 testing revealed she was compound heterozygous for pathogenic variants c.427_429delGAA, (p.Glu143del) and c.1186C>T, (p.Arg396Trp). Case 2, a 36-year-old woman presented 4 days after the delivery of healthy twins with dyspnoea, bradycardia, severe headaches, hypertension and generalized tonic-clonic seizures after an uneventful pregnancy. She was hypercalcaemic with a suppressed PTH, normal 25(OH)D, and elevated 1,25(OH)2D levels. Her symptoms partially responded to i.v. saline and corticosteroids in the short term but bisphosphonates such as Pamidronate and Zoledronic acid did not result in sustained improvement. Denosumab 120 mg SCI successfully treated the hypercalcaemia which resolved completely 2 months post-partum. CYP24A1 testing revealed she was homozygous for the pathogenic variant c.427_429delGAA, (p.Glu143del).
Hypercalcaemia in pregnancy can be associated with considerable morbidity with few options available for management.
In non-PTH-related hypercalcaemia the diagnosis of CYP24A1 deficiency should be considered.
Making a definitive diagnosis of CYP24A1 deficiency by genetic testing delays the diagnosis, while the availability of serum 24,25-dihydroxyvitamin D (24,25(OH)2D) will expedite a diagnosis.
In pregnant women with CYP24A1 deficiency hypercalcaemia can worsen in the post-partum period and is more likely to occur with twin pregnancies but generally resolves within 2–3 months.
Therapeutic alternatives are limited in pregnancy and their effectiveness is short-lived and mostly ineffective. Denosumab used in both our patients after delivery was the most effective agent normalizing calcium and may have benefit as a long-term therapeutic agent in preventing complications in patients with CYP24A1 deficiency.