Giant parathyroid tumours in primary hyperparathyroidism: a systematic review

A Rare Case of a Giant Parathyroid Adenoma in a Young Male Patient

A giant parathyroid adenoma (GPTA) is a rare type of primary hyperparathyroidism (PHPT) characterized by a weight of at least 3.5 g. We report a case of a 24-year-old male patient who presented with generalized fatigue and pathological left humeral fracture, found to have a serum calcium level of 16.9 mg/dL and a parathyroid hormone (PTH) level of 3,164 pg/mL. A 5.4 g right inferior type E parathyroid adenoma was excised with normalization of PTH levels. His clinical course was complicated by hungry bone syndrome and required management by a multidisciplinary team involving internal medicine, endocrinology, endocrine surgery, orthopedic surgery, nephrology, thoracic surgery, and genetics.

An exceptionally rare case of a giant parathyroid adenoma with carcinoma-like presentation

Giant parathyroid adenoma (GPA) is an extremely rare cause of primary hyperparathyroidism (PHPT) and may sometimes mimic parathyroid carcinoma (PC). Parathyroid carcinoma is also a very rare entity. Both preoperative and postoperative diagnosis of the two conditions remains a challenge. The purpose of this article is to present the diagnostic and therapeutic approach used for a 76-year-old female patient with a GPA measuring 5.4 × 2.3 cm, mimicking PC. The patient was referred to our clinic for the management of severe hypercalcemia revealed during the neurological evaluation of psychiatric and cognitive symptoms, confusion, weakness, and bone pain. PHPT was confirmed based on the patient's biochemical profile, which showed extremely high levels of serum calcium and parathyroid hormone (PTH). Wholebody computed tomography revealed a large nodule below the inferior pole of the right lobe of the thyroid gland and no further pathology in other organs. En bloc resection of the tumor with removal of the ipsilateral hemithyroid and other involved tissues was performed. Histopathological evaluation was diagnostic for a GPA. Post-surgery hungry bone syndrome (HBS) developed and was treated. However, the patient succumbed 3 weeks later due to septic shock. GPA is an exceptionally rare endocrine tumor that should be suspected along with PC in patients with significantly elevated levels of PTH and calcium, and/or palpable neck mass. In our case, diagnosis was based principally on histopathological examination together with clinical presentation, biochemical profile, and imaging studies. Resection of the tumor remains the treatment of choice.

Impact of parathyroidectomy on quality of life in primary hyperparathyroidism

Patients with primary hyperparathyroidism (PHPT) frequently report symptoms that are associated with the disease and impact on their quality of life (QoL). While parathyroidectomy corrects calcium and PTH levels, its impact on improving patients' QoL is not clear. In this single centre prospective study, we aimed to assess the impact of a parathyroidectomy on PHPT patients' pre and post parathyroidectomy QoL over a period of three years and nine months. PHPT patients, undergoing parathyroidectomy, voluntarily completed a modified Pasieka Parathyroidectomy Assessment Score (PAS), a tool correlating 13 PHPT symptoms to QoL. Sixty patients with PHPT (mean age 64 years, female to male 4:1) were included in the study. Pre parathyroidectomy, the most common symptoms were: feeling tired easily (n = 58); being forgetful (n = 51); pain in the joints (n = 49); feeling irritable (n = 48) bone pain (n = 45); feeling weak (n = 45); mood swings (n = 42); and being thirsty (n = 42). Parathyroidectomy reduced severity of mean total PAS by 44%, improving from 509 to 284 (p < 0.01). A total of 77% (n = 46) of patients experienced some improvement of PAS. The five most severe symptoms (highest reported individual PAS) showed a significant reduction post parathyroidectomy (p < 0.01): feeling tired easily (mean PAS 65 vs 38); pain in the joints (52 vs 31); being thirsty (46 vs 22); being forgetful (45 vs 28); and bone pain (45 vs 27). Patients with PHPT demonstrated impaired QoL as evidenced by the PAS, and assessing this is valuable in treatment planning. Parathyroidectomy impacts the symptoms that most affect QoL and significantly improves overall QoL in these patients.

Preoperative localization of water clear cell giant parathyroid adenoma: A case report

Primary hyperparathyroidism commonly results from a solitary parathyroid adenoma. A water clear cell parathyroid adenoma represents a rare histological variant. This report presents the challenges of preoperative detection of a giant parathyroid adenoma, which was of the water clear cell variant. A case of severe hypercalcemia in a patient without clinical symptoms and equivocal findings on standard imaging modalities, in which the use of [11C]C-Methionine PET/CT facilitated the preoperative detection of a giant parathyroid adenoma. Histopathological examination confirmed the diagnosis of a water clear cell giant parathyroid adenoma following surgical excision. These findings highlight the significance of advanced imaging techniques in the detection and management of a rare form of parathyroid adenoma.

Imaging features and surgical management of giant parathyroid adenoma with autoinfarction

Autoinfarction of a parathyroid adenoma can have an atypical clinicoradiologic features that can mimic an inflammatory process or malignancy. In addition, the associated fibrosis makes surgical resection more challenging than for regular parathyroid adenomas. The implications of these findings are that while autoinfarction of parathyroid adenomas is a rare phenomenon, this entity should be considered when there are heterogeneous and cystic components on imaging in patients without hypercalcemia. Ultimately, histopathology is necessary for definitive diagnosis.

Influence of Vitamin D Deficiency on Cyclin D1-Induced Parathyroid Tumorigenesis

Primary hyperparathyroidism (PHPT) is a common endocrinopathy for which several pathogenic mechanisms, including cyclin D1 overexpression, have been identified. Vitamin D nutritional status may influence parathyroid tumorigenesis, but evidence remains circumstantial. To assess the potential influence of vitamin D insufficiency/deficiency on initiation or progression of parathyroid tumorigenesis, we superimposed vitamin D insufficiency or deficiency on parathyroid tumor-prone parathyroid hormone-cyclin D1 transgenic mice. Mice were placed on diets containing either 2.75 IU/g, 0.25 IU/g, or 0.05 IU/g cholecalciferol, either prior to expected onset of PHPT or after onset of biochemical PHPT. When introduced early, superimposed vitamin D insufficiency/deficiency had no effect on serum calcium or on parathyroid gland growth. However, when introduced after the onset of biochemical PHPT, vitamin D deficiency led to larger parathyroid glands without differences in serum biochemical parameters. Our results suggest that low vitamin D status enhances proliferation of parathyroid cells whose growth is already being tumorigenically driven, in contrast to its apparent lack of direct proliferation-initiating action on normally growing parathyroid cells in this model. These results are consistent with the hypothesis that suboptimal vitamin D status may not increase incidence of de novo parathyroid tumorigenesis but may accelerate growth of a preexisting parathyroid tumor.

Large parathyroid adenomas: Potential mechanisms to reconcile adenoma size and disease phenotype

Parathyroid adenomas weighing more than 3.5 g are reported variously as "atypical", "large" or "giant" parathyroid adenomas. All such adenomas are rare variants accounting for no more than 1.5% of all parathyroid adenomas. Large parathyroid adenomas are often associated with more severe form of the disease, including osteitis fibrosa cystica (OFC) and share many biochemical, histological, and molecular features of both benign and malignant parathyroid neoplasms, and are considered a distinct clinical entity. However, the pathogenesis of oversized parathyroid adenomas and the often-associated skeletal phenotype remains unclear. We present 5 cases of primary hyperparathyroidism (PHPT) with OFC, an uncommon manifestation of contemporary PHPT, associated with larger parathyroid adenomas, seen in the Bone and Mineral Disorders Clinic of the Henry Ford Health in the last 30 years to illustrate the critical role of vitamin D nutrition in the pathogenesis of both the OFC and adenoma size. The estimated prevalence of OFC was very low 0.2%, 5 of the >3000 surgically confirmed cases of PHPT seen during this time. The mean ± SD values were: age: 36.8 ± 22.1 years (4 of the 5 <36years), serum calcium 11.6 ± 1.1 mg/dl, alkaline phosphatase 799 ± 487 IU/L, PTH 1440 ± 477 pg/ml, 25-hydroxyvitamin D 13.0 ± 8.9 ng/ml, 1,25-dihyroxyvitamin D 26.5 ± 13.7 pg/ml, urine calcium 562 ± 274 mg/day, and parathyroid adenoma weight 4.53 ± 2.2 g. Parathyroidectomy led to the resolution of both the biochemical indices and OFC in each patient without recurrence over >10 years of follow-up. Because OFC is a very rare in the West, but very common areas of endemic vitamin D deficiency, we also examined the relationship between vitamin D nutrition, as assessed by serum 25-hydroxyvitamin D level, and parathyroid adenoma weight as well as prevalence of OFC in two large secularly diverse cohorts of patients with PHPT (Detroit, USA and Chandigarh, India). Based on this relationship and the relative prevalence of OFC in these two large cohorts, we propose that vitamin D nutrition (and perhaps calcium nutrition) best explains both the adenoma size and prevalence of OFC.

Margin Free Resection Achieves Excellent Long Term Outcomes in Parathyroid Cancer

Long-term outcomes of parathyroid cancer remain poorly documented and unsatisfactory. This cohort includes 25 consecutive parathyroid cancer patients with median follow-up of 10.7 years (range 4.1−26.5 years). Pre-operative work-up in the center identified a suspicion of parathyroid cancer in 17 patients. En bloc resection, including the recurrent laryngeal nerve in 4/17 (23.5%), achieved cancer-free resection margins (R0) in 82.4% and lasting loco-regional disease control in 94.1%. Including patients referred after initial surgery elsewhere, R0 resection was achieved in merely 17/25 (68.0%) of patients. Cancer-positive margins (R1) in 8 patients led to local recurrence in 50%. On multivariate analysis, only margin status prevailed as independent predictor of recurrence free survival (χ2 19.5, p < 0.001). Local excision alone carried a 3.5-fold higher risk of positive margins than en bloc resection (CI95: 1.1−11.3; p = 0.03), and a 6.4-fold higher risk of locoregional recurrence (CI95: 0.8−52.1; p = 0.08). R1-status was associated with an 18.0-fold higher risk of recurrence and redo surgery (CI95: 1.1−299.0; p = 0.04), and a 22.0-fold higher probability of radiation (CI95: 1.4−355.5; p = 0.03). In patients at risk, adjuvant radiation reduced the actuarial risk of locoregional recurrence (p = 0.05). When pre-operative scrutiny resulted in upfront oncological surgery achieving cancer free margins, it afforded 100% recurrence free survival at 5- and 10-year follow-up, whilst failure to achieve clear margins caused significant burden by outpatient admissions (176 vs. 4 days; χ2 980, p < 0.001) and exposure to causes for concern (1369 vs. 0 days; χ2 11.3, p = 0.003). Although limited by cohort size, our study emphasizes the paradigm of getting it right the first time as key to improve survivorship in a cancer with excellent long-term prognosis.

Giant Parathyroid Tumor: Parathyroid Adenoma versus Parathyroid Carcinoma

Parathyroid adenoma is the most common cause of primary hyperparathyroidism (PHPT). We present the preoperative detection of a giant parathyroid adenoma (GPA) using (^99mTc)-sestamibi parathyroid scintigraphy in a patient presenting with severely elevated parathyroid hormone, hypercalcemia, hypophosphatemia, and vitamin D insufficiency. The patient complained of cerebral symptoms and intermittent abdominal discomfort without constipation. After surgical removal of the hyperactive parathyroid gland and D vitamin supplementation, all blood tests were normalized. The clinical and paraclinical characteristics of GPA may raise the suspicion of parathyroid carcinoma, but not absolutely in this case.