Search Results (50)

Background/Objectives: Secondary hyperparathyroidism (SHPT) is a major chronic kidney disease complication requiring parathyroidectomy in medically refractory cases. Limited data exist on imaging performance and metabolic outcomes, particularly uric acid metabolism, following parathyroidectomy in dialysis patients. Methods: This retrospective cohort study included 68 hemodialysis patients undergoing parathyroidectomy for SHPT. Biochemical parameters including iPTH, calcium, phosphorus, alkaline phosphatase, uric acid, hemoglobin, and erythropoiesis-stimulating agent doses were measured preoperatively and up to 36 months postoperatively. We evaluated the diagnostic accuracy of preoperative ultrasonography and dual-phase ¹²³I/^99mTc sestamibi scintigraphy for parathyroid localization. Surgical techniques included subtotal parathyroidectomy (70.6%) and total parathyroidectomy (29.4%). Results: Parathyroidectomy resulted in dramatic iPTH reductions at 12 months (p < 0.001). Hungry bone syndrome occurred in 89.7% of patients. Notably, uric acid levels showed no significant change (p = 0.280), while hemoglobin improved and erythropoiesis-stimulating agent requirements decreased. Ultrasonography demonstrated 45.5% sensitivity with 98.0% positive predictive value, while scintigraphy achieved 55.0% sensitivity with 99.2% positive predictive value. Combined imaging improved sensitivity to 60.0% while maintaining 97.8% positive predictive value. Concurrent thyroid pathology was identified in nine patients (13.2%), including multinodular goiter in seven patients (10.3%) and papillary thyroid carcinoma in two patients (2.9%). Conclusions: Parathyroidectomy effectively treats refractory SHPT with sustained biochemical control, and combined imaging provides complementary preoperative information. Unlike primary hyperparathyroidism, no detectable change in uric acid levels was observed after parathyroidectomy in dialysis patients; given the limited statistical power, this finding is hypothesis-generating and suggests that hyperuricemia in this population may require independent management. Full article

Background/Objectives: Parathyroid imaging is used for preoperative localization rather than biochemical diagnosis. Conventional planar and SPECT-based scintigraphy may yield equivocal reports when thyroid activity obscures lesion localization. This study evaluated whether combining software-assisted subtraction imaging with ultrasound-correlated interpretation improves reporting certainty and reduces ambiguity. Methods: This prospective reporting study included 96 consecutive patients referred for parathyroid scintigraphy because of biochemical or clinical suspicion of primary hyperparathyroidism. Each anonymized imaging dataset was evaluated by two independent consensus reader pairs using different interpretation strategies. The control arm (CTRL) used conventional dual-time-point Tc-99m sestamibi planar and SPECT images with Tc-99m pertechnetate thyroid images. The intervention arm (INT) additionally used software-assisted subtraction images and ultrasound-correlated interpretation. Endpoints included suspected parathyroid adenoma (PTA)-positive reporting, certainty, clinically actionable localization, high-confidence localization, and non-actionable reporting. Surgical/pathological reference localization was available in 22 operated patients. Results: INT increased PTA-positive reporting compared with CTRL [82/96 (85.4%) vs. 53/96 (55.2%), p < 0.001]. Median certainty increased from 1 (IQR, 0–2) to 3 (IQR, 1–3) (p < 0.001). Clinically actionable localization increased from 32/96 (33.3%) to 68/96 (70.8%) (p < 0.001), and high-confidence localization increased from 17/96 (17.7%) to 55/96 (57.3%) (p < 0.001). Non-actionable reporting decreased from 64/96 (66.7%) to 28/96 (29.2%). In the operated subgroup, correct localization was higher with INT [20/22 (90.9%) vs. 12/22 (54.5%), p = 0.008]. Conclusions: Software-assisted subtraction imaging, when combined with ultrasound-correlated interpretation, improved the clinical usability of conventional parathyroid scintigraphy by increasing reporting certainty, reducing ambiguity, and improving actionable localization. Reference-based findings were supportive, and ongoing follow-up is expected to provide surgical/pathological confirmation for robust diagnostic accuracy analyses. Full article

Background: Accurate preoperative localization of hyperfunctioning parathyroid glands remains challenging, particularly in secondary hyperparathyroidism where multiglandular disease may compromise scintigraphic performance. Methods: Our study evaluated biochemical, morphometric, and histopathological predictors of ^99mTc-sestamibi scintigraphy detectability in both primary and secondary hyperparathyroidism. The study group included a total of 162 patients with primary and secondary hyperparathyroidism who underwent dual-phase ^99mTc-sestamibi scintigraphy followed by parathyroidectomy. Demographics, biochemical parameters, histopathological features, lesion volume and scintigraphic findings were assessed at patient and lesion level. Results: In primary hyperparathyroidism, adenomas were larger and more frequently detected than hyperplastic glands. Lesion volume and solid growth pattern were found as positive predictors of sestamibi uptake. In secondary hyperparathyroidism, nodular hyperplasia was associated with larger volume, higher cellularity, and more frequent localizing studies. Upper quadrant position and diffusely hyperplastic lesions were associated with higher lesion miss rates, while lesion volume increased the likelihood of detection. Conclusions: Our findings highlight that ^99mTc-sestamibi scintigraphy performance is strongly influenced by lesion volume, histopathological architecture and anatomical position, underscoring the needs for cautious interpretation of negative or incomplete scans, especially in secondary hyperparathyroidism. Full article

Background: Accurate preoperative localization of hyperfunctioning parathyroid glands is essential for minimally invasive surgery in primary hyperparathyroidism (PHPT). Although dual-phase ^99mTc-MIBI planar scintigraphy is widely used, its diagnostic performance may be limited in small or ectopic lesions. Hybrid SPECT/CT imaging combines functional and anatomical information and may improve localization accuracy. The aim of this study is to evaluate the diagnostic contribution of SPECT/CT to dual-phase ^99mTc-MIBI planar scintigraphy for preoperative localization in patients with PHPT. Methods: This retrospective study included 128 patients with biochemically confirmed PHPT who underwent dual-phase ^99mTc-MIBI planar scintigraphy followed by delayed-phase SPECT/CT imaging before parathyroidectomy between January 2020 and May 2024. Imaging findings were compared with postoperative histopathological results. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. The effects of lesion size, biochemical parameters, and ultrasonographic findings on imaging performance were also evaluated. Results: Histopathology confirmed parathyroid lesions in 122 of 128 patients (95.3%). The sensitivity, specificity, PPV, NPV, and accuracy of planar imaging were 57.4%, 66.7%, 97.2%, 7.1%, and 57.8%, respectively, whereas those of SPECT/CT were 92.6%, 66.7%, 98.3%, 30.8%, and 91.4%, respectively. SPECT/CT findings showed significant concordance with histopathology (p = 0.001), while planar imaging did not (p = 0.247). Among lesions smaller than 1 cm, sensitivities were 37.1% for planar imaging and 91.4% for SPECT/CT. SPECT/CT also provided superior anatomical localization, particularly in ectopic lesions and in patients with concomitant thyroid pathology. Conclusions: SPECT/CT demonstrated substantially higher diagnostic performance than dual-phase planar scintigraphy for preoperative localization in PHPT. Its incremental value was particularly evident in subcentimeter lesions, ectopic parathyroid adenomas, and patients with coexisting thyroid disease. Full article

Background: Parathyroid lipoadenoma, oncocytic parathyroid adenoma, and water-clear cell parathyroid adenoma (WCCA) are exceptionally rare subtypes of parathyroid adenoma, whose real clinical impact remains unclear. Methods: We performed a literature review and comparison of these uncommon subtypes of parathyroid adenoma, as these lesions may be associated with distinct clinical, pathological and radiological phenotypes. Results: The three groups were comparable in terms of age and gender, mainly affecting middle-aged women. As for the biochemical findings, although PTH level did not show statistically significant differences among the three adenomas, in the two-tail comparison between WCCAs and lipoadenomas, there was a trend towards higher PTH values (p = 0.058). However, serum calcium levels differed significantly, with higher levels in WCCAs than in lipoadenomas (12.1 vs. 11.3 mg/dL; p = 0.002). From a preoperative point of view, ultrasound positivity was significantly higher in WCCAs than in lipoadenomas and oncocytic adenomas (97% vs. 50% vs. 55.3%, p < 0.001), compared to scintigraphy positivity, which was comparable between subtypes and relatively suboptimal (66.7% vs. 64.3% vs. 61.3%; p = 0.825); WCCAs also had an overall more voluminous morphological phenotype. Conclusions: This review, although limited by its reliance primarily on case reports and small case series, confirms that lipoadenoma, oxyphilic adenoma, and WCCAs are rare but clinically relevant subtypes of parathyroid adenoma. These entities may be associated with atypical presentations of primary hyperparathyroidism (including difficult preoperative localization and clinicopathological features raising suspicion of malignancy) and should be recognized as a potential source of diagnostic difficulty. A better understanding of these rare subtypes may improve clinicopathological interpretation, increase awareness of potential diagnostic pitfalls and support a more personalized diagnostic and surgical approach in the future. Full article

Background/Objectives: Secondary hyperparathyroidism (SHPT) is a common and clinically significant complication of advanced chronic kidney disease and may require surgical intervention when medical therapy fails. This study aimed to evaluate the association between parathyroid gland burden, defined by gland number and size parameters, and biochemical disease severity in patients undergoing parathyroidectomy for SHPT, and to assess the concordance between preoperative imaging findings and intraoperative observations. Although parathyroid gland enlargement is a hallmark of SHPT, the clinical relevance of parathyroid gland number and overall gland burden in relation to biochemical disease severity and the accuracy of preoperative imaging remains incompletely defined. Methods: This single-center, retrospective observational study included adult patients who underwent parathyroidectomy for secondary hyperparathyroidism between January 2015 and December 2020. Demographic, clinical, laboratory, imaging, intraoperative, and histopathological data were analyzed. Parathyroid gland burden was assessed based on gland number, largest gland diameter, and total gland burden. Associations between gland morphology and biochemical parameters were evaluated using correlation analyses and multivariable logistic regression. Agreement between preoperative imaging and intraoperative findings was assessed using diagnostic performance metrics, contingency analysis, and the weighted kappa coefficient. Results: A total of 101 patients were included. Patients with three or more enlarged parathyroid glands had significantly higher preoperative parathyroid hormone and alkaline phosphatase levels, higher serum phosphorus levels, and lower calcium and vitamin D levels (all p < 0.05). Total gland burden and largest gland diameter were positively correlated with parathyroid hormone and alkaline phosphatase levels. In multivariable analysis, higher parathyroid hormone levels, longer dialysis duration, and vitamin D deficiency were independently associated with high gland burden. Preoperative imaging demonstrated moderate agreement with intraoperative findings (weighted kappa = 0.46; 95% CI, 0.29–0.63). Separate evaluation of imaging modalities showed that both ultrasonography and scintigraphy had relatively high sensitivity but limited specificity for detecting extensive gland involvement. Conclusions: In patients undergoing parathyroidectomy for secondary hyperparathyroidism, increased parathyroid gland burden is associated with greater biochemical disease severity. Preoperative imaging shows limited concordance with intraoperative findings and should be interpreted cautiously, particularly in the presence of multiglandular disease. These findings support the integration of morphological parameters into comprehensive preoperative assessment while highlighting the need for larger prospective, multicenter studies with standardized imaging protocols and long-term follow-up. Full article

Objective: This study assessed the relationship between serum calcium (Ca) and parathyroid hormone (PTH) levels, the size and weight of the enlarged parathyroid gland (PG), and the results of technetium-99m-metoxyisobutylisonitrile (MIBI) parathyroid scintigraphy with single-photon emission computed tomography/computed tomography. Methods: Among 252 patients who underwent surgery for hyperparathyroidism between October 2022 and March 2025 at the Department of Endocrine Surgery of the University Hospital in Krakow, 212 patients with primary hyperparathyroidism (PHPT) were selected and divided into the MIBI(−) (n = 49) and MIBI(+) (n = 163) groups. Results: MIBI was positive in 76.9% and negative in 23.1% patients with PHPT. Mean PTH in the MIBI(+) and MIBI(−) groups was 177.3 ± 144.7 and 127.7 ± 59.4 pg/mL, respectively. Significant differences were found in PTH (p < 0.01), maximum excised PG size (p < 0.01), and weight (p < 0.01). PTH predicted positive scintigraphy in univariate analysis (OR = 2.65; 95% CI: 1.19–5.89; p = 0.02) and showed a borderline association in the multivariate model (OR = 2.47; 95% CI: 0.95–6.41; p = 0.06). Optimal cut-offs for predicting MIBI positivity were 135.0 pg/mL for PTH (AUC = 0.64), 0.73 g for PG weight (AUC = 0.81), and 18.0 mm for PG maximum size (AUC = 0.78). The Wisconsin index (Ca × PTH) was associated with positive MIBI (OR = 2.58; 95% CI: 1.15–5.78; p = 0.02), with an optimal cut-off of 256.0. Serum total Ca levels showed no significant association with positive MIBI (p = 0.60). Conclusions: Serum PTH levels, Wisconsin index, and enlarged PG size and weight may help predict parathyroid scintigraphy outcomes. Full article

Purpose: Hyperparathyroidism (HPT) is a condition marked by excessive secretion of parathyroid hormone (PTH), leading to disturbances in calcium, phosphate, and vitamin D metabolism. HPT is classified into primary (pHPT), secondary (sHPT), and tertiary (tHPT) types, which can cause systemic complications. Parathyroidectomy (PTX) remains the cornerstone treatment for pHPT and refractory cases of sHPT and tHPT. Methods: A retrospective review was conducted on 10 pediatric patients who underwent PTX for HPT at our clinic between 2016 and 2024. Demographic data, preoperative imaging, laboratory findings, surgical details, pathology reports, and postoperative outcomes were analyzed. Patients were categorized as having either pHPT (n = 6) or renal HPT (r-HPT; n = 4), which included one case of sHPT and three cases of tHPT. Results: The mean age of pHPT and r-HPT patients was 15 and 13 years, respectively. While 50% of pHPT patients were female, all r-HPT patients were female. Preoperative imaging localized parathyroid lesions using ultrasonography in all cases, but Sestamibi scintigraphy had a lower detection rate (66.7%). Minimally invasive parathyroidectomy was performed in single-gland pHPT cases, while bilateral neck exploration was used for multiglandular pHPT and all r-HPT cases. No intraoperative complications were observed. Postoperatively, all patients demonstrated normalized calcium, phosphate, and PTH levels with significant symptomatic improvement. Hungry bone syndrome developed in one r-HPT patient and was managed successfully. No recurrences were noted during an average follow-up of 39 months. Conclusions: PTX is a safe and effective treatment for pediatric HPT, providing excellent biochemical and clinical outcomes. Multidisciplinary collaboration is crucial in managing pediatric cases, particularly those with complex renal HPT. Full article

Parathyroid carcinoma (PC) is an exceedingly rare endocrine malignancy, accounting for less than 1% of all primary hyperparathyroidism (pHPT) cases. It typically presents with pronounced hypercalcemia and markedly elevated parathyroid hormone (PTH) levels. Accurate imaging plays a pivotal role in diagnosis, staging, surgical planning, and long-term surveillance, although differentiating PC from benign disease on imaging remains a significant challenge. A multimodal imaging strategy combining cervical ultrasonography (US) and nuclear medicine techniques provides high sensitivity for lesion detection. Ultrasonography with advanced detective flow imaging allows detailed anatomical assessment and evaluation of vascular patterns of the primary tumor. [^99mTc]Tc-methoxyisobutylisonitrile ([^99mTc]Tc-MIBI) scintigraphy frequently demonstrates prolonged tracer retention in PC, while [¹⁸F]fluorocholine positron emission tomography/computed tomography (PET/CT) and positron emission tomography/magnetic resonance (PET/MR) imaging have shown superior performance for detecting both primary tumors and metastatic disease due to its higher spatial resolution and higher molecular sensitivity. [¹⁸F]FDG PET serves as an adjunct modality for identifying aggressive, metabolically active lesions. Emerging radiotracers such as [¹⁸F]-fibroblast activation protein inhibitor ([¹⁸F]FAPI) and [⁶⁸Ga]Ga-trivehexin have shown potential in cases where initial imaging is inconclusive. Theranostic strategies that integrate molecular imaging with targeted radioligand therapy may transform PC management by enabling personalized treatment approaches tailored to each tumor’s biological and imaging characteristics. This review aims to evaluate available imaging modalities for PC diagnosis and provide guidance for their clinical application. Full article

Brown tumors (BTs) are rare osteolytic lesions that typically occur in association with primary or secondary hyperparathyroidism (PHP and SHP). Excessive secretion of parathyroid hormone induces increased bone resorption, resulting in lesions characterized by fibrosis, vascularization, and hemosiderin deposition. The most common sites include the jaws, ribs, pelvis, and long bones. Clinical manifestations may involve pain, swelling, or pathological fractures. We present the case of a mandibular BT in a 48-year-old female with chronic renal failure and secondary hyperparathyroidism. The patient exhibited progressive mandibular swelling with radiological features resembling an aggressive odontogenic or malignant lesion. Laboratory analysis confirmed markedly elevated parathyroid hormone levels, while scintigraphy demonstrated increased focal uptake in the mandible and ribs. Histopathological evaluation revealed multinucleated giant cells within a fibrous stroma, consistent with BT. Despite initiation of systemic endocrine therapy, the lesion continued to enlarge, necessitating complete surgical excision of the mandibular mass. This case underscores the diagnostic dilemmas of mandibular BT, which may closely mimic aggressive jaw pathologies. Importantly, while many BTs regress after systemic management of hyperparathyroidism, this case illustrates that surgical excision may be unavoidable in patients with unstable systemic status or progressive local disease. Comprehensive clinical, radiological, laboratory, and histopathological evaluation remains essential to ensure timely diagnosis and appropriate treatment. Full article

Background: Hypophosphatemia is a frequently underestimated metabolic disorder, yet it can be one of the first biochemical findings in primary hyperparathyroidism (PHPT). Current diagnostic and surgical criteria for PHPT do not include serum phosphate, despite its potential value as an early marker. Methods: We report the case of a 79-year-old woman with type 2 diabetes mellitus, hypertension and osteoarthritis, followed since 2015 for persistent hypophosphatemia (0.8 mg/dL) and stress fractures. Results: Initial calcium and vitamin D levels were normal, but PTH was elevated. Bone scintigraphy revealed multiple stress fractures, while ultrasound and sestamibi scan were inconclusive. Despite cholecalciferol and calcitriol supplementation, hypophosphatemia persisted. From 2023, progressive hypercalcemia developed (10.9 mg/dL), with sustained hypophosphatemia (1.7 mg/dL), persistently high PTH (121 pg/mL) and markedly elevated FGF-23 (1694 kRU/L). Renal phosphate wasting was demonstrated, with reduced tubular reabsorption. An 18F-fluorocholine PET-CT performed in 2024 identified two right parathyroid adenomas, establishing the diagnosis of PHPT. The patient was referred for parathyroidectomy. Conclusions: Hypophosphatemia may serve as a complementary biomarker in the diagnostic and therapeutic approach to PHPT, but only after other potential causes of low phosphate levels have been excluded, as illustrated in this case. Its consideration could facilitate the early identification of PHPT and improve clinical decision-making, particularly in patients who do not meet classical surgical indications. Full article

Drug–radiopharmaceutical interactions can significantly alter radiotracer biodistribution, complicating diagnostic accuracy. This case report describes a 64-year-old male who underwent a Technetium-99m-methoxyisobutyl isonitrile (^99mTc-MIBI) parathyroid scan for suspected primary hyperparathyroidism. Initially, the patient was asked to discontinue his medications for his chronic illnesses for 24 h prior to the scan. However, the images revealed significantly reduced counts/tracer uptake in the thyroid, parathyroid and cardiac tissues in both the early and delayed phases. After a detailed review of his medication profile, it was postulated that there were potential interactions involving multiple P-glycoprotein (P-gp) substrates with specific emphasis on amlodipine, atorvastatin and telmisartan. The patient was advised to discontinue all medications for 72 h prior to the date of a repeat scan which was scheduled for two weeks after his initial scan. The repeat scan successfully detected a small focus of marked tracer retention in the left inferior parathyroid bed, suggestive of a small parathyroid adenoma. Post-surgery, the focus identified on the scan was removed and histologically confirmed to be a parathyroid adenoma. This is the first report of its kind among nuclear medicine patients in Jamaica. It highlights the importance of reviewing medication history prior to nuclear imaging, particularly when using radiotracers affected by P-gp mechanisms. This is crucial for mitigating against false-negative results, thus ensuring accurate diagnosis and appropriate clinical management. Full article

Background: Parathyromatosis, an exceptional clinical and pathological entity, involves multiple small nodules of hyper-functional parathyroid tissue scattered throughout the neck and/or mediastinum, in relationship with a prior parathyroidectomy (mostly) or embryologic remnant. Since its first identification in 1975, many aspects of this condition have remained a matter of debate. Objective: We introduce an updated perspective on parathyromatosis covering the main clinical points for everyday practice, from diagnosis to management, as well as the current level of pathogenic understanding. Methods: A narrative review. Results: A total of 22 patients were identified, with the following characteristics: an age range of 33–68 (mean 46.18) years; 4/22 subjects <40 years; female-to-male ratio = 14:8. Of the 22 subjects, 21 had undergone previous parathyroidectomy for primary (n = 14) or secondary (n = 7) hyperparathyroidism. One case was a surgically naïve patient. Analysis of the surgical procedures (seeding circumstances) revealed the following: parathyroid cyst removal, left/right parathyroidectomy; removal of 3.5 parathyroids ± self-transplantation, VATS for mediastinal parathyroid tumours. Parathyroidectomy was accompanied by thyroid surgery (n = 3 patients), specifically hemi-thyroidectomy, partial left-thyroid lobectomy, and partial thyroidectomy. The shortest timeframe from parathyroidectomy to parathyromatosis-related hyperparathyroidism recognition was 1 year, and the longest was 17 years. The highest number of previous surgeries was four. The recognition of parathyromatosis was due to the clinical picture of associated hyperparathyroidism, except for in 2/21 cases with incidental detection. The implant sites coincided with the prior surgical area, but also with unusual locations (clavicle, pleura, mediastinum, sternocleidomastoid muscle and forearm, thyroid). The imaging evaluation included ultrasound plus CT plus 99m-Tc sestamibi scintigraphy, as well as (variable rates) neck MRI, SPECT/CT, 11-Choline PET-CT, Gallium-68 DOTATATE, and 4D CT. Surgery implied serial procedures in some cases (e.g., up to seven). The surgery spectrum largely varied, including not only cervicotomy, but also thoracoscopy, VATS, pericardial adipose tissue excision and thymectomy, etc. Conclusions: Awareness remains a key factor when approaching such an unusual ailment underlying little-understood pathogenic loops, which, if left unrecognized and untreated, might impair patients’ quality of life and the overall parathyroid disease burden. Full article

Background and clinical significance: Paget’s disease of bone involves anomalies of the bone metabolism; however, the presence of tumor-derivate abnormal parathyroid hormone (PTH) levels does not represent one of these disturbances. To our best knowledge, the association with normocalcemic variant of primary hyperparathyroidism has been limitedly reported, and here we introduce such an unusual overlap in a male suffering from osteoporosis. Case presentation: A 71-year-old, non-smoker man was hospitalized for mild, nonspecific dysphagia, asthenia, decreased appetite, and mild weight loss during the latest 2 months. His medical history included cardiovascular conditions and an abnormal PTH level with normal serum calcium under daily cholecalciferol supplements (tested twice during latest 12 months). The lab findings pointed out a normocalcemic primary hyperparathyroidism (PTH of maximum 163 pg/mL, and total calcium of 9.3 mg/dL) caused by a right parathyroid tumor of 1.2 cm, as confirmed by computed tomography (CT). Additionally, CT showed a left humerus lesion suggestive of Paget’s disease of bone, a confirmation that also came from the whole-body bone scintigraphy. The subject presented increased P1NP and osteocalcin, CrossLaps as bone formation, and resorption markers, with normal total alkaline phosphatase. CT scan also detected multiple vertebral fractures and small kidney stones. Zoledronate i.v. (3 mg, adjusted for creatinine clearance) was administered, taking into consideration all three bone ailments (Paget’s disease, high PTH/calcium, and osteoporosis) with further follow-up. Conclusions: This case highlights the following technical notes based on a real-life setting: 1. Despite the mentioned bone diseases, no bone pain was present. Loss of appetite, dysphagia, and asthenia may be a consequence of mineral metabolism disturbances. 2. The panel of blood bone turnover markers levels might be related to both hyperparathyroidism and Paget’s disease; notably, rare cases of Paget’s disease with normal alkaline phosphatase were prior reported. 3. A meticulous differentiation between secondary and primary hyperparathyroidism is required. In this instance, lack of hypocalcaemia and vitamin D deficiency was suggestive of the diagnosis of a primary variant. 4. Kidney stones, osteoporosis, and osteoporotic fractures may be correlated with both conditions, as well, while a dual perspective of the therapy, since the patient was not a parathyroid surgery candidate, included a first dose of zoledronate with consecutive long-term follow-up. To our best knowledge, the co-presence of normocalcemic variant of primary hyperparathyroidism represents an exceptional finding in a patient synchronously diagnosed with Pagetic lesions and osteoporosis complicated with vertebral fractures. Full article

Introduction: Primary hyperparathyroidism (pHPT) is an endocrine disorder characterized by excessive parathyroid hormone production, typically due to adenomas, hyperplasia, or carcinoma. Preoperative imaging plays a critical role in guiding surgical planning, particularly in selecting patients for minimally invasive procedures. While first-line imaging techniques, such as ultrasound and 99mTc-sestamibi scintigraphy, are standard, advanced second-line imaging modalities like 18F-fluorocholine PET/CT (FCH-PET) and four-dimensional computed tomography (4D-CT) have emerged as valuable tools when initial diagnostics are inconclusive. Methods: This article provides an updated review and recommendations of the role of these advanced imaging techniques in localizing parathyroid adenomas. Results: FCH-PET has shown exceptional sensitivity (94% per patient, 96% per lesion) and is particularly useful in detecting small or ectopic adenomas. Despite its higher sensitivity, it can yield false positives, particularly in the presence of thyroid disease. On the other hand, 4D-CT offers detailed anatomical imaging, aiding in the identification of parathyroids in challenging cases, including recurrent disease and ectopic glands. Studies suggest that FCH-PET and 4D-CT exhibit similar diagnostic performance and could be complementary in preoperative planning of most difficult situations. Conclusions: This article also emphasizes a multimodal approach, where initial imaging is followed by advanced techniques only in cases of uncertainty. Although 18F-fluorocholine PET/CT is favored as a second-line option, 4D-CT remains invaluable for its high spatial resolution and ability to guide surgery in complex cases. Despite limitations in evidence, these imaging modalities significantly enhance the accuracy of parathyroid localization, contributing to more targeted and minimally invasive surgery. Full article