Parathyroid fine-needle aspiration with parathyroid hormone washout as a preoperative localisation of parathyroid adenoma-A retrospective study.

OBJECTIVE: The use of parathyroid lesion aspiration in preoperative adenoma localisation is controversial. Concerns have been raised regarding both immediate safety (hematoma, infection, alterations on a subsequent histologic preparate) and long-term safety (seeding). We aimed to evaluate the short- and long-term safety, and the efficacy, of parathyroid fine-needle aspiration with parathyroid hormone washout as a localisation modality of parathyroid adenoma in patients with primary hyperparathyroidism. DESIGN: A retrospective study. PATIENTS: The sample comprised 29 patients with primary hyperparathyroidism who underwent minimally invasive parathyroidectomy at a tertiary referral centre, following localisation with parathyroid hormone washout. MEASUREMENTS: We reviewed all parathyroid hormone washout procedures performed during 2011-2021. Clinical, biochemical, and imaging information; and cytology, surgery, and pathology reports were extracted from electronic medical records. RESULTS: Parathyroid hormone levels from the needle wash were 2.1-112.5 times the upper limit of the serum norm. Other than mild neck discomfort, no immediate procedure complications were documented. Fibrotic changes and necrosis were reported in two patients, with no effect on the final pathologic diagnosis or surgery course. No long-term complications (seeding, or parathyromatosis) were found. A total of 26 (90%) patients who were operated following a positive parathyroid hormone washout result were normocalcemic at the end of a mean 38.1-month follow-up period. CONCLUSIONS: Parathyroid fine-needle aspiration with parathyroid hormone washout was accurate. Immediate, surgical, or delayed complications were not demonstrated in our series. This approach might be considered for selected patients.

Parathyroid carcinoma: Single centre experience.

OBJECTIVE: Parathyroid Carcinoma is a rare malignant neoplasm, accounting for less than 1% of primary hyperparathyroidism cases. Parathyroid carcinomas are characterized by markedly elevated levels of PTH, severe hypercalcemia and established target organ damage. The authors report the experience of a single centre regarding the management and outcome of patients with parathyroid carcinomas and revise relevant literature. DESIGN: Retrospective review of all patients with parathyroid carcinoma evaluated at a tertiary oncologic centre from 1991 until 2021. RESULTS: Seventeen patients were identified (10 males), with a mean age at diagnosis of 53 ± 16 years and a median follow-up of 16.5 years. Most patients presented with hypercalcemia (n = 15), with a mean serum calcium concentration of 13.5 mg/dl (9.6-16.5) and mean PTH of 1173 pg/ml (276-2500). Hyperparathyroidism-mediated organ damage was observed in most patients (n = 16), with predominant renal (n = 12) and skeletal (n = 9) complications. En bloc surgical resection was performed in nine patients. Three patients underwent adjuvant radiotherapy. Recurrence was observed in 8 cases (47.1%) after a median of 24 months following surgery and no independent predictors of recurrence were identified. The overall survival and disease specific survival at 5-year was 88% and 94%, respectively. CDC73 mutations were present in 38.5% of analysed patients and one patient was diagnosed with MEN1. CONCLUSION: Parathyroid carcinoma is associated with a significant rate of recurrence and limited effective treatment beyond initial complete surgical resection. Therefore, preoperatively high index of suspicion is paramount to optimize patient care. This is, to our knowledge, the largest Portuguese cohort published so far.

A visual deep learning model to predict abnormal versus normal parathyroid glands using intraoperative autofluorescence signals.

BACKGROUND: Previous work demonstrated that abnormal versus normal parathyroid glands (PGs) exhibit different patterns of autofluorescence, with former appearing darker and more heterogenous. Our objective was to develop a visual artificial intelligence model using intraoperative autofluorescence signals to predict whether a PG is abnormal (hypersecreting and/or hypercellular) or normal before excision during surgical exploration for primary hyperparathyroidism. METHODS: A total of 906 intraoperative parathyroid autofluorescence images of 303 patients undergoing parathyroidectomy/thyroidectomy were used to develop model. Autofluorescence image of each PG was uploaded into the visual artificial intelligence platform as abnormal or normal. For deep learning, randomly chosen 80% of data was used for training, 10% for testing, 10% for validation. The area under the receiver operating characteristic (AUROC), area under the precision-recall curve (AUPRC), recall (sensitivity), and precision (positive predictive value) of the model were calculated. RESULTS: AUROC and AUPRC of the model to predict normal and abnormal PGs were 0.90 and 0.93, respectively. Recall and precision of the model were 89% each. CONCLUSION: Visual artificial intelligence platforms may be used to compare the autofluorescence signal of a given parathyroid gland against a large database. This may be a new adjunctive tool for intraoperative assessment of parathyroid glands during surgical exploration for primary hyperparathyroidism.

Giant parathyroid tumours in primary hyperparathyroidism: a systematic review.

PURPOSE: Giant parathyroid adenoma (GPA) can present with severe biochemical derangement similar to the clinical presentation of parathyroid carcinoma (PC). This study aims to present the current evidence on surgical management of GPAs in primary hyperparathyroidism. METHODS: A systematic review of the literature on GPAs was conducted following the PRISMA guidelines. Data on clinical, biochemical, preoperative diagnostic, and surgical methods were analysed. RESULTS: Sixty-one eligible studies were included reporting on 65 GPAs in eutopic, ectopic mediastinal, and intrathyroidal locations (61.5%, 30.8%, and 7.7%, respectively). A palpable neck mass was present in 58% of GPAs. A total of 90% of patients had symptoms including fatigue, skeletal pain, pathological fracture, nausea, and abdominal pain. Ninety percent of patients had significant hypercalcaemia (mean 3.51 mmol/L; range: 2.59-5.74 mmol/L) and hyperparathyroidism with PTH levels on average 14 times above the upper limit of the normal reference. There was no correlation between the reported GPA size and PTH nor between GPA weight and PTH (p = 0.892 and p = 0.363, respectively). Twenty-four percent had a concurrent thyroidectomy for suspicious features, intrathyroidal location of GPA, or large goitre. Immunohistochemistry such as Ki-67, parafibromin, and galectin-3 was used in 18.5% of cases with equivocal histology. Ninety-five percent of GPAs were benign with 5% reported as atypical adenomas. CONCLUSION: The reported data on GPAs are sparse and heterogeneous. In GPAs with suspicious features for malignancy, en bloc resection with concurrent thyroidectomy may be considered. In the presence of equivocal histological features, ancillary immunohistochemistry is advocated to differentiate GPAs from atypical adenomas and PCs.

Application value of contrast-enhanced ultrasound in preoperative localization of microwave ablation for primary hyperparathyroidism.

BACKGROUND: Ultrasonography (US) and 99m Technetium-sestamibi scintigraphy (99m Tc-MIBI) are currently first-line imaging modalities to localize parathyroid adenomas with sensitivities of 80% and 84%, respectively. Therefore, finding other modalities to further improve the diagnostic accuracy for preoperative localization is critically needed. PURPOSE: To evaluate the application value of contrast-enhanced ultrasound (CEUS) in the preoperative localization of microwave ablation (MWA) for primary hyperparathyroidism (PHPT). METHODS: Between December 2012 and May 2021, 100 PHPT patients (34 males and 66 females; mean age, 56.31 ± 13.43 years; age range, 25-85 years) with 130 suspected parathyroid nodules were enrolled. US, CEUS, and 99m Tc-MIBI were performed for the localization of pathological parathyroid glands. All patients were performed MWA under ultrasound guidance. All the suspected parathyroid nodules underwent core needle biopsy under ultrasound guidance during MWA to confirm the pathology. The diagnostic performance of all the imaging tests was analyzed in comparison with the pathological results. RESULTS: A total of 130 nodules suspected to be of parathyroid origin from preoperative localization images were confirmed by pathological results, of which 116 were of parathyroid origin, and 14 were not of parathyroid origin. The sensitivity, specificity, accuracy, and the area under receiver operating characteristic curve of CEUS in the localization of pathological parathyroid glands were 100%, 92.86%, 99.23%, and 0.964, which were significantly higher than those of US (93.10%, 42.86%, 87.69%, and 0.680) and 99m Tc-MIBI (81.90%, 42.86%, 77.69%, and 0.624) (p < 0.05). The sensitivity and accuracy of CEUS were 100% and 97.22%, which were higher than those of 99m Tc-MIBI (65.62% and 63.89%) or US (75.00% and 72.22%) in patients with multiple parathyroid glands (p < 0.05). For smaller parathyroid adenomas (≤2 cm in diameter), the sensitivities of CEUS in locating hyperfunctioning parathyroid glands were 100%, which was significantly higher than that of 99m Tc-MIBI (73.68% and 84.31%, p < 0.05). CONCLUSIONS: CEUS is a valuable preoperative localization method for PHPT patients performed MWA, especially for the patients with smaller pathological parathyroid gland and multiple glandular lesions.

Challenging NICE guidelines on parathyroid surgery.

BACKGROUND: National Institute of Clinical Excellence (NICE) recommend against routinely using Intra-Operative Parathyroid Hormone (IOPTH) for first-time parathyroid surgery due to its cost and minimal surgical benefit. The European Society of Endocrine Surgeons differ from this and recommends IOPTH with conflicting pre-operative or single imaging. NICE guidance acknowledged that this may change practice in larger centres. We devised a retrospective single-centre cohort study to analyse the impact of IOPTH on decision-making and cost-effectiveness. METHODOLOGY: First-time parathyroidectomy procedures for primary hyperparathyroidism were assessed between 2017 and 2019. Ultrasound (US) and Sestamibi with parathyroid single-photon emission with computed tomography (SPECT-CT) were compared with IOPTH. The contribution of IOPTH to cure and cost effectiveness ratio was calculated. RESULTS: 114 cases were included, with IOPTH performed in all cases, SPECT-CT in 112 and US in 108 cases. A cure rate of 99.1% (113/114) was achieved. 11.4% (13/114) of the cure rate was influenced by IOPTH (P 0.01), instigating further exploration when its levels didn't decrease. This included 7.1% (4/56) in the concordant-imaging cohort. IOPTH accuracy (96.5%) was significantly superior (P = 0.03) to both US (80%) and SPECT-CT (81%). Comparing the total costs for IOPTH testing over 2 years (£39,721) with 13 potential re-operative procedures in its absence (£63,536), a positive cost-effectiveness ratio of £1832 per re-operative procedure averted was achieved. CONCLUSION: Abandoning IOPTH in first-time parathyroid surgery is too ambitious when weighing the cost of re-operative surgery against cost savings obtained by using routine IOPTH to achieve an improved cure rate, even in concordant imaging.

Factors related to a non-localising technetium 99m sestamibi scan result during parathyroid adenoma imaging in primary hyperparathyroidism.

OBJECTIVES: The aim of this study is to investigate factors that are associated with having a non-localising 99m Tc-sestamibi scan. DESIGN: A retrospective study was performed on patients that underwent parathyroid surgery performed within a single institution between 2001 and 2018. SETTING: Single tertiary centre for parathyroid surgery. PARTICIPANTS: 230 patients underwent surgery for primary hyperparathyroidism due to a solitary parathyroid adenoma and had preoperative 99m Tc-sestamibi imaging. MAIN OUTCOME MEASURES: Variables including age, gender, intra-operative location of parathyroid adenoma, adenoma weight and pre- and postoperative calcium and parathyroid hormone levels were investigated through univariate and multivariate analysis to identify any association with having a non-localising (negative) 99m Tc-sestamibi scan result. RESULTS: Multivariate analysis identified that right-sided adenomas (P = .038), superior adenomas (P = .042) and a lower preoperative PTH level (P = .034) were all individual factors associated with having a negative 99m Tc-sestamibi scan result. Although the weight of the adenoma was significant on univariate analysis (P = .029), this was not demonstrated on multivariate analysis (P = .422). CONCLUSION: Factors that were associated with having non-localising 99m Tc-sestamibi scan were right-sided adenomas, superior adenomas and lower preoperative PTH level. Further large prospective multicentre studies are needed to further evaluate these initial findings.

Parathyroid adenoma with prominent lymphocytic infiltrate having histological features highly suggestive of IgG4-related disease: a case report and literature review.

Parathyroid adenoma with prominent lymphocytic infiltrate is a rare disease. Until now, 11 patients have been reported. Herein, we report a 57-year-old man who had a neck mass that was incidentally found. Aspiration cytology and subsequent needle biopsy of the tumor were performed and suggested papillary thyroid carcinoma. From the resected specimen, however, the patient was finally diagnosed with parathyroid adenoma with prominent lymphocytic infiltrate, characterized by hyperplastic parathyroid cells with nuclear atypia within fibrotic stroma along with numerous lymphocytes forming germinal centers. Some eosinophils and plasma cells were also observed with some histological features highly suggestive of IgG4-related disease (IgG4-RD), including increased IgG4-positive plasma cells and IgG4/IgG-positive plasma cell ratio, storiform-type fibrosis, and obliterative phlebitis. It turned out that microfollicular or trabecular architecture and cellular atypia with high expression of HBME-1 observed in the aspiration cytology and needle biopsy had been misinterpreted as a thyroid malignancy. This is the first report describing microscopic features of aspiration cytology and needle biopsy of parathyroid adenoma with prominent lymphocytic infiltrate, warning that it can mimic papillary thyroid carcinoma in biopsy specimens. Furthermore, the IgG4-RD-like features of the present case and previous reports imply that parathyroid adenoma with prominent lymphocytic infiltrate may be a type of IgG4-RD.

Efficacy of Superselective Neck Dissection in Detecting Metastasis in Patients with cN0 Papillary Thyroid Carcinoma at High Risk of Lateral Neck Metastasis.

Background Material and Methods Results Conclusions.

Fine needle cytology pre-surgical differentiation of parathyroid neoplasms: Is it reliable?

BACKGROUND: Fine needle cytology (FNC) of a parathyroid neoplasia (PN) is reliable, but needs to be confirmed by Parathormone (PTH) and Thyroglobulin (TG) immunoassay on needle washing or by immunocytochemistry (ICC) evaluation. The differentiation between parathyroid adenoma (PA), atypical adenoma (PAA) and carcinoma (PC) is difficult on histology or even impossible on FNC. The aim of this study was to evaluate possible cytological criteria to classify FNC-PN further. METHODS: Twenty-three FNC samples of PN and parathyroid cysts were rather then have been reviewed. The series includes 18 PNs, 4 cysts and 1 Thyr3B (histologically diagnosed as PA). Cytological features were: cellularity, patterns (follicular, solid or papillary), clear, oncocytic, isolated cells, nuclear atypia, cytoplasmic inclusions, nucleoli and mitoses. Data were compared with the histological controls. RESULTS: Seventeen PNs, 2 cysts and 1 Thyr3B FNC samples were histologically diagnosed as PA (16), PAA (2) and PC (2). Two cysts and 1 PN were not confirmed histologically. Cytological features and incidences were: high cellularity (1 PA, 1 PAA, 2 PCs), follicular (8 PAs, 1 PAA), solid (5 PAs, 1 PC), papillary pattern (1PA, 1 PAA, 1 PC), clear cells (4 PAs, 1 PAA, 2 PCs), oncocytic cells (6 PAs, 1 PAA, 2 PCs), isolated cells (5 PAs, 2 PAAs, 2 PCs), nuclear atypia (2 PAs, 1 PAA, 2 PCs), cytoplasmic inclusions (4 PAs, 2 PCs), nucleoli (2 PCs) and mitoses (2 PCs). CONCLUSION: Evident nucleoli and mitoses may suggest the differentiation between PA and PC. However, further investigations are required to confirm these preliminary observations.

A new technique to simplify the minimally invasive parathyroidectomy: Ultrasound-assisted guided wire localization for solitary parathyroid adenomas.

OBJECTIVE: To investigate the benefits of ultrasound-assisted guided wire localization in MIP for selected cases. METHODS: In this prospective, nonrandomised study, we included 36 patients with solitary parathyroid adenomas diagnosed preoperatively by 99m Tc sesta MIBI scintigraphy and/or neck ultrasonography. An ultrasound-guided wire was placed in the solitary parathyroid adenoma preoperatively. MIPs were performed under local anaesthesia plus sedation. After the excision, the parathyroidectomy was confirmed with postoperative ultrasonography. RESULTS: There were 36 patients included in our study. The mean age was 54.89±11.28 years, and 30 patients were females (83.3%). Preoperative PTH and calcium (Ca) levels were 269.5 pg/mL (83.5-5,000 pg/mL) and 12.2 mg/dL (11.1-20 mg/dL), respectively. Postoperative serum PTH and Ca levels were 42.04±26.65 pg/mL and 8.95±0.74 mg/dL, respectively. The mean operation time was 21.69±6.4 minutes and the average hospitalisation time was 18 hours (range: 10-72 hours). CONCLUSIONS: Ultrasound-assisted guided wire localization may be useful in selected MIP cases. The MIP advantages include higher success rates and being easy to learn and practise.

Huge Parathyroid Adenoma with Dysphagia Presentation; A Case Report from Southern Iran.

Parathyroid adenoma is a benign tumor of the parathyroid glands. The cause of most parathyroid adenomas is unknown. Parathyroid adenoma increases the secretion of parathyroid hormone and results in primary hyperparathyroidism. High amounts of parathyroid hormone in the blood cause the imbalance of calcium, which leads to various complications such as kidney stones, depression, lethargy, nausea, vomiting, abdominal pain, myalgia, bone and joint pain, hoarseness, etc. Oropharyngeal dysphagia is defined as having problem in swallowing due to abnormalities in the structure and function of oropharynx and other related organs. The exact prevalence of dysphagia caused by parathyroid adenoma is unknown, but since this complication can lead to increased mortality and morbidity, its diagnosis is important. It is difficult to distinguish parathyroid malignancies from parathyroid adenoma even after surgery. Therefore, the final diagnosis is possible through surgery and histopathological evaluation. Here, a case of parathyroid adenoma with first presentation of generalized weakness and dysphagia has been reported.

Concurrent parathyroidectomy and caesarean section in the third trimester.

BACKGROUND: Primary hyperparathyroidism is the most common cause of hypercalcemia in the general population. It is a rare complication of pregnancy that is difficult for clinicians to recognize, yet it can have important and devastating effects for both mother and baby. CASE: A 27-year-old primigravida at 32+3 weeks' gestation had a serum calcium level in excess of 2.75 mmol/L and evidence of HELLP syndrome. She underwent concurrent parathyroidectomy and Caesarean section. Neither the mother nor the neonate developed hypocalcemia postoperatively. The mother's parathyroid tissue was pathologically atypical, and a left hemithyroidectomy was performed at three months postpartum. CONCLUSION: When hyperparathyroidism is diagnosed in the third trimester, concurrent parathyroidectomy and Caesarean section is a safe and reasonable option for management. This should be performed by a multidisciplinary team with careful monitoring of the calcium levels of both mother and neonate after surgery.

Contexte : L'hyperparathyroïdie primaire constitue la cause la plus courante d'hypercalcémie au sein de la population générale. Bien qu'il s'agisse d'une complication rare de la grossesse qui est difficile à reconnaître pour les cliniciens, elle peut exercer d'importants effets dévastateurs tant chez la mère que chez l'enfant. Cas : Une primigravide de 27 ans à 32+3 semaines de gestation présentait un taux sérique de calcium dépassant 2,75 mmol/l et des symptômes indiquant la présence du syndrome HELLP. Elle a subi, de façon concomitante, une parathyroïdectomie et une césarienne. Ni la mère ni le nouveau-né n'en sont venus à présenter une hypocalcémie postopératoire. L'examen pathologique a révélé que le tissu parathyroïde de la mère était atypique et une hémithyroïdectomie gauche a été menée à trois mois postpartum. Conclusion : Lorsqu'une hyperparathyroïdie est diagnostiquée au cours du troisième trimestre, la tenue concomitante d'une parathyroïdectomie et d'une césarienne constitue une option sûre et raisonnable pour ce qui est de la prise en charge. Ces interventions devraient être menées par une équipe multidisciplinaire et s'accompagner d'une surveillance rigoureuse des taux de calcium de la mère et du nouveau-né après la chirurgie.

Ultrasonographic features of normal parathyroid glands confirmed during thyroid surgery in adult patients.

PURPOSE: This study was performed to examine the ultrasonography (US) features of normal parathyroid glands (PTGs) that were identified on preoperative US and subsequently confirmed during thyroid surgery. METHODS: This retrospective study included a consecutive sample of 161 patients (mean±standard deviation age, 56±14 years; 128 women) with 294 normal PTGs identified on preoperative US PTG mapping and confirmed during thyroidectomy. A presumed normal PTG on US was defined as a small, round to oval, hyperechoic structure in the central neck. These presumed normal PTGs, as identified on preoperative US, were mapped onto thyroid computed tomography images and diagrams of the thyroid gland and neck. During the preoperative real-time US examinations, the location, size, shape, echogenicity, echotexture, and intraglandular vascular flow of the identified presumed PTGs were assessed. These characteristics were compared between superior and inferior PTGs using the generalized estimating equation method. RESULTS: The typical US features of homogeneous hyperechogenicity without intraglandular vascular flow were observed in 267 (90.8%) normal PTGs, while atypical features, including isoechogenicity (1.0%), heterogeneous echotexture with focal hypoechogenicity (5.8%), and intraglandular vascular flow (3.7%), were noted in 27 (9.2%). Inferior PTGs were more frequently identified in posterolateral (36.1% vs. 5.3%) and thyroid pole locations (29.9% vs. 5.3%), and less frequently in posteromedial locations (29.2% vs. 88.0%), compared to superior PTGs (P<0.001 for each comparison). CONCLUSION: Most normal PTGs displayed the typical US features of homogeneous hyperechogenicity without intraglandular vascular flow. However, in rare cases, normal PTGs exhibited atypical features, including isoechogenicity, heterogeneous echotexture with focal hypoechogenicity, and intraglandular vascular flow.

Comparison of intraoperative imaging with a portable gamma camera with extemporaneous histology in minimally invasive surgery for primary hyperparathyroidism.

INTRODUCTION: The curative treatment of primary hyperparathyroidism (PPH) is surgical and today it can be performed by minimally invasive surgery (MIS) and also be radioguided (RG) if a radiopharmaceutical with affinity for the parathyroid tissue that can be detected with gamma-detector probes or with a portable gamma camera (PGC) is injected. AIM: The objective is to assess whether intraoperative scintigraphy (GGio) with PGC can replace intraoperative pathological anatomy (APio) to determine if the removed specimen is an abnormal parathyroid. MATERIAL AND METHOD: 92 patients underwent CMI RG--HPP with PGC after the administration of a dose of 99 mTc-MIBI. The information provided by the PGC in the analysis of the excised specimens is qualitatively compared (capture yes/no) with the result of the intraoperative pathological anatomy (APio). The Gold standard is the definitive histology. RESULTS: 120 excised pieces are evaluated with GGio and APio. There were 110 agreements (95TP and 15TN) and 10 disagreements (3FP and 7FN). Of the 120 lesions, 102 were parathyroid and 18 were non-parathyroid. There was good agreement between intraoperative scintigraphy imaging (GGio) and PA, 70.1% according to Cohen's Kappa index. The GGio presented the following values ​​of Sensitivity, Specificity, Positive Predictive Value, Negative Predictive Value, Positive Likelihood Ratio, Negative Likelihood Ratio and Overall Value of the Test (93.1%, 83.3%, 96.9%, 68.2%, 5.59, 0.08 and 0.92 respectively). CONCLUSION: GGio is a rapid and effective surgical aid technique to confirm/rule out the possible parathyroid nature of the lesions removed in PPH surgery, but it cannot replace histological study.

Revision parathyroid surgery - challenges and considerations in comparison to primary surgery.

OBJECTIVE: Revision parathyroidectomy is made necessary by recurrent or persistent parathyroid disease. This study aimed to identify challenges in revision surgery compared to primary parathyroid surgery. METHODS: All revision parathyroidectomies performed by one surgeon over a 17-year period were assessed for demographics, imaging, histology, biochemistry, cure rate, gland weight, gland location and gland ectopia, and compared to a series of 100 primary parathyroidectomies. RESULTS: Twenty-eight revision surgical procedures were identified. Sestamibi scanning for gland localisation was superior to ultrasound in both primary and revision surgery. Pre-operative calcium and gland weight were significantly higher in revision cases. There were no significant differences in post-operative calcium levels, pre- or post-operative parathyroid hormone levels, or gland location. 36 per cent of glands excised in revision surgery were ectopic, compared to 25 per cent in primary procedures. The cure rate was significantly lower in revision surgery. CONCLUSION: Revision parathyroidectomy patients present with higher pre-operative calcium and larger adenomas; the cure rate is significantly lower in these patients.

Ectopic parathyroid adenoma in a patient with multiple endocrine tumours.

Not required for Clinical Vignette.

Incidentally discovered parathyroid lipoadenoma in thyroid surgery: A case report and review of the literature.

Parathyroid lipoadenoma is a rare type of parathyroid adenoma, described as a single parathyroid adenoma with more than 50% fat on histologic examination and an unknown etiology, which is one of the rare causes of primary hyperparathyroidism. The difficulty of parathyroid lipoadenoma is mainly diagnosed by preoperative imaging localization. We hope to arouse attention to the parathyroid adenoma which is difficult to locate through our case report. The patient was a middle-aged male with a body mass index of 38.4 kg/m2 who admitted to our hospital with a 40-day history of an untreated thyroid nodule. We incidentally discovered parathyroid lipoadenoma in his thyroid surgery. His prognosis was good, and there were no signs of recurrence at his 12-month follow-up appointment. We believe that parathyroid lipoadenoma needs to rely on paraffin pathology to make a final diagnosis. This case report serves as a reminder that parathyroid lipoadenomas are also possible in patients who do not have primary hyperparathyroidism preoperatively and who have negative imaging. Clinicians must carefully examine the adipose tissue for the presence of parathyroid lipoadenomas during thyroid surgery to avoid postoperative hypoparathyroidism and persistent hypocalcaemia.

A Rare Case of Recurrent Parathyroid Adenomas After Initial Parathyroidectomy.

Hyperparathyroidism usually presents asymptomatically with elevated levels of calcium and parathyroid hormone; this biochemical imbalance establishes the diagnosis. In 80-85% of cases of primary hyperparathyroidism, singular parathyroid adenomas occur. In rare cases, this problem occurs due to multiple adenomas, multiglandular hyperplasia, or parathyroid carcinoma. Recurrent primary hyperparathyroidism (R-PHPT), as demonstrated in this case, is defined as hypercalcemia that arises after six months of normocalcemia following initial surgery for PHPT. The aim of this report is to describe the diagnosis and management of three parathyroid adenomas in a patient, two of which occurred after an initial partial parathyroidectomy.