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Open access

Aisling McCarthy, Sophie Howarth, Serena Khoo, Julia Hale, Sue Oddy, David Halsall, Brian Fish, Sashi Mariathasan, Katrina Andrews, Samson O Oyibo, Manjula Samyraju, Katarzyna Gajewska-Knapik, Soo-Mi Park, Diana Wood, Carla Moran and Ruth T Casey

Summary

Primary hyperparathyroidism (PHPT) is characterised by the overproduction of parathyroid hormone (PTH) due to parathyroid hyperplasia, adenoma or carcinoma and results in hypercalcaemia and a raised or inappropriately normal PTH. Symptoms of hypercalcaemia occur in 20% of patients and include fatigue, nausea, constipation, depression, renal impairment and cardiac arrythmias. In the most severe cases, uraemia, coma or cardiac arrest can result. Primary hyperparathyroidism in pregnancy is rare, with a reported incidence of 1%. Maternal and fetal/neonatal complications are estimated to occur in 67 and 80% of untreated cases respectively. Maternal complications include nephrolithiasis, pancreatitis, hyperemesis gravidarum, pre-eclampsia and hypercalcemic crises. Fetal complications include intrauterine growth restriction; preterm delivery and a three to five-fold increased risk of miscarriage. There is a direct relationship between the degree of severity of hypercalcaemia and miscarriage risk, with miscarriage being more common in those patients with a serum calcium greater than 2.85 mmol/L. Neonatal complications include hypocalcemia. Herein, we present a case series of three women who were diagnosed with primary hyperparathyroidism in pregnancy. Case 1 was diagnosed with multiple endocrine neoplasia type 1 (MEN1) in pregnancy and required a bilateral neck exploration and subtotal parathyroidectomy in the second trimester of her pregnancy due to symptomatic severe hypercalcaemia. Both case 2 and case 3 were diagnosed with primary hyperparathyroidism due to a parathyroid adenoma and required a unilateral parathyroidectomy in the second trimester. This case series highlights the work-up and the tailored management approach to patients with primary hyperparathyroidism in pregnancy.

Learning points:

  • Primary hyperparathyroidism in pregnancy is associated with a high incidence of associated maternal fetal and neonatal complications directly proportionate to degree of maternal serum calcium levels.

  • Parathyroidectomy is the definitive treatment for primary hyperparathyroidism in pregnancy and was used in the management of all three cases in this series. It is recommended when serum calcium is persistently greater than 2.75 mmol/L and or for the management of maternal or fetal complications of hypercalcaemia. Surgical management, when necessary is ideally performed in the second trimester.

  • Primary hyperparathyroidism is genetically determined in ~10% of cases, where the likelihood is increased in those under 40 years, where there is relevant family history and those with other related endocrinopathies. Genetic testing is a useful diagnostic adjunct and can guide treatment and management options for patients diagnosed with primary hyperparathyroidism in pregnancy, as described in case 1 in this series, who was diagnosed with MEN1 syndrome.

  • Women of reproductive age with primary hyperparathyroidism need to be informed of the risks and complications associated with primary hyperparathyroidism in pregnancy and pregnancy should be deferred and or avoided until curative surgery has been performed and calcium levels have normalised.

Open access

Peter Novodvorsky, Ziad Hussein, Muhammad Fahad Arshad, Ahmed Iqbal, Malee Fernando, Alia Munir and Sabapathy P Balasubramanian

Summary

Spontaneous remission of primary hyperparathyroidism (PHPT) due to necrosis and haemorrhage of parathyroid adenoma, the so-called ‘parathyroid auto-infarction’ is a very rare, but previously described phenomenon. Patients usually undergo parathyroidectomy or remain under close clinical and biochemical surveillance. We report two cases of parathyroid auto-infarction diagnosed in the same tertiary centre; one managed surgically and the other conservatively up to the present time. Case #1 was a 51-year old man with PHPT (adjusted (adj.) calcium: 3.11 mmol/L (reference range (RR): 2.20–2.60 mmol/L), parathyroid hormone (PTH) 26.9 pmol/L (RR: 1.6–6.9 pmol/L) and urine calcium excretion consistent with PHPT) referred for parathyroidectomy. Repeat biochemistry 4 weeks later at the surgical clinic showed normal adj. calcium (2.43 mmol/L) and reduced PTH. Serial ultrasound imaging demonstrated reduction in size of the parathyroid lesion from 33 to 17 mm. Twenty months later, following recurrence of hypercalcaemia, he underwent neck exploration and resection of an enlarged right inferior parathyroid gland. Histology revealed increased fibrosis and haemosiderin deposits in the parathyroid lesion in keeping with auto-infarction. Case #2 was a 54-year-old lady admitted with severe hypercalcaemia (adj. calcium: 4.58 mmol/L, PTH 51.6 pmol/L (RR: 1.6–6.9 pmol/L)) and severe vitamin D deficiency. She was treated with intravenous fluids and pamidronate and 8 days later developed symptomatic hypocalcaemia (1.88 mmol/L) with dramatic decrease of PTH (17.6 pmol/L). MRI of the neck showed a 44 mm large cystic parathyroid lesion. To date, (18 months later), she has remained normocalcaemic.

Learning points:

  • Primary hyperparathyroidism (PHPT) is characterised by excess parathyroid hormone (PTH) secretion arising mostly from one or more autonomously functioning parathyroid adenomas (up to 85%), diffuse parathyroid hyperplasia (<15%) and in 1–2% of cases from parathyroid carcinoma.

  • PHPT and hypercalcaemia of malignancy, account for the majority of clinical presentations of hypercalcaemia.

  • Spontaneous remission of PHPT due to necrosis, haemorrhage and infarction of parathyroid adenoma, the so-called ‘parathyroid auto-infarction’, ‘auto-parathyroidectomy’ or ‘parathyroid apoplexy’ is a very rare in clinical practice but has been previously reported in the literature.

  • In most cases, patients with parathyroid auto-infarction undergo parathyroidectomy. Those who are managed conservatively need to remain under close clinical and biochemical surveillance long-term as in most cases PHPT recurs, sometimes several years after auto-infarction.

Open access

Benjamin Kwan, Bernard Champion, Steven Boyages, Craig F Munns, Roderick Clifton-Bligh, Catherine Luxford and Bronwyn Crawford

Summary

Autosomal dominant hypocalcaemia type 1 (ADH1) is a rare familial disorder characterised by low serum calcium and low or inappropriately normal serum PTH. It is caused by activating CASR mutations, which produces a left-shift in the set point for extracellular calcium. We describe an Australian family with a novel heterozygous missense mutation in CASR causing ADH1. Mild neuromuscular symptoms (paraesthesia, carpopedal spasm) were present in most affected individuals and required treatment with calcium and calcitriol. Basal ganglia calcification was present in three out of four affected family members. This case highlights the importance of correctly identifying genetic causes of hypocalcaemia to allow for proper management and screening of family members.

Learning points:

  • ADH1 is a rare cause of hypoparathyroidism due to activating CASR mutations and is the mirror image of familial hypocalciuric hypercalcaemia.

  • In patients with ADH1, symptoms of hypocalcaemia may be mild or absent. Basal ganglia calcification may be present in over a third of patients.

  • CASR mutation analysis is required for diagnostic confirmation and to facilitate proper management, screening and genetic counselling of affected family members.

  • Treatment with calcium and activated vitamin D analogues should be reserved for symptomatic individuals due to the risk of exacerbating hypercalciuria and its associated complications.

Open access

Cheuk-Lik Wong, Chun-Kit Fok and Vicki Ho-Kee Tam

Summary

We report a case of elderly Chinese lady with neurofibromatosis type-1 presenting with longstanding palpitation, paroxysmal hypertension and osteoporosis. Biochemical testing showed mild hypercalcaemia with non-suppressed parathyroid hormone level suggestive of primary hyperparathyroidism, and mildly elevated urinary fractionated normetanephrine and plasma-free normetanephrine pointing to a catecholamine-secreting pheochromocytoma/paraganglioma. Further scintigraphic investigation revealed evidence of a solitary parathyroid adenoma causing primary hyperparathyroidism and a left pheochromocytoma. Resection of the parathyroid adenoma and pheochromocytoma resulted in normalization of biochemical abnormalities and hypertension. The rare concurrence of primary hyperparathyroidism and pheochromocytoma in neurofibromatosis type-1 is discussed.

Learning points:

  • All NF-1 patients who have symptoms suggestive of a pheochromocytoma/paraganglioma (PPGL), even remotely, should undergo biochemical testing.

  • The initial biochemical tests of choice for PPGL in NF-1 are either plasma-free metanephrines or urinary fractionated metanephrines. Any elevations of metanephrines should be carefully evaluated for the presence of PPGLs in NF-1 patients.

  • Primary hyperparathyroidism (PHPT) is described in subjects with NF-1. Due to the lack of epidemiological and functional studies, their association is yet to be substantiated. Meanwhile, PHPT may further exacerbate the metabolic bone defect in these patients and should be treated when present according to published guidelines.

  • Coexistence of PPGL and PHPT can occur in subjects with NF-1, mimicking multiple endocrine neoplasia type 2 (MEN2).

Open access

Caroline Bachmeier, Chirag Patel, Peter Kanowski and Kunwarjit Sangla

Summary

Primary hyperparathyroidism (PH) is a common endocrine abnormality and may occur as part of a genetic syndrome. Inactivating mutations of the tumour suppressor gene CDC73 have been identified as accounting for a large percentage of hyperparathyroidism-jaw tumour syndrome (HPT-JT) cases and to a lesser degree account for familial isolated hyperparathyroidism (FIHP) cases. Reports of CDC73 whole gene deletions are exceedingly rare. We report the case of a 39 year-old woman with PH secondary to a parathyroid adenoma associated with a large chromosomal deletion (2.5 Mb) encompassing the entire CDC73 gene detected years after parathyroidectomy. This case highlights the necessity to screen young patients with hyperparathyroidism for an underlying genetic aetiology. It also demonstrates that molecular testing for this disorder should contain techniques that can detect large deletions.

Learning points:

  • Necessity of genetic screening for young people with hyperparathyroidism.

  • Importance of screening for large, including whole gene CDC73 deletions.

  • Surveillance for patients with CDC73 gene mutations includes regular calcium and parathyroid hormone levels, dental assessments and imaging for uterine and renal tumours.

Open access

Shintaro Kawai, Hiroyuki Ariyasu, Yasushi Furukawa, Reika Yamamoto, Shinsuke Uraki, Ken Takeshima, Kenji Warigaya, Yuji Nakamoto and Takashi Akamizu

Summary

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome characterized by renal phosphate wasting leading to hypophosphatemia due to excessive actions of fibroblast growth factor 23 (FGF23) produced by the tumors. Although the best way of curing TIO is complete resection, it is usually difficult to detect the culprit tumors by general radiological modalities owing to the size and location of the tumors. We report a case of TIO in which the identification of the tumor by conventional imaging studies was difficult. Nonetheless, a diagnosis was made possible by effective use of multiple modalities. We initially suspected that the tumor existed in the right dorsal aspect of the scapula by 68Ga-DOTATOC positron emission tomography/computed tomography (68Ga-DOTATOC-PET/CT) and supported the result by systemic venous sampling (SVS). The tumor could also be visualized by 3T-magnetic resonance imaging (MRI), although it was not detected by 1.5T-MRI, and eventually be resected completely. In cases of TIO, a stepwise approach of 68Ga-DOTATOC-PET/CT, SVS and 3T-MRI can be effective for confirmation of diagnosis.

Learning points:

  • TIO shows impaired bone metabolism due to excessive actions of FGF23 produced by the tumor. The causative tumors are seldom detected by physical examinations and conventional radiological modalities.

  • In TIO cases, in which the localization of the culprit tumors is difficult, 68Ga-DOTATOC-PET/CT should be performed as a screening of localization and thereafter SVS should be conducted to support the result of the somatostatin receptor (SSTR) imaging leading to increased diagnosability.

  • When the culprit tumors cannot be visualized by conventional imaging studies, using high-field MRI at 3T and comparing it to the opposite side are useful after the tumor site was determined.