Intrathyroidal Parathyroid Adenoma Research Articles

Concurrent Intrathyroidal Parathyroid Adenoma and Papillary Thyroid Microcarcinoma: A Case Report

Papillary thyroid carcinoma (PTC) is the commonest endocrine thyroid malignancy. The concurrent incidence of intrathyroidal parathyroid adenoma and papillary thyroid carcinoma is an infrequent finding. Surgical treatment via excision is the only definitive management approach. Here in we present a case report of intrathyroid parathyroid adenoma with incidental papillary micro carcinoma in a 36 year-old-female who initially presented with osteoporosis.

Treating intra-thyroid parathyroid adenoma by radiofrequency is a valuable alternative to hemithyroidectomy

Background Parathyroid adenoma (PA) is the most common cause of primary hyperparathyroidism (PHPT). One infrequent scenario (0.7%–6%) is represented by intra-thyroid PA (I-PA), an ectopic variant of the parathyroid gland included in the thyroid parenchyma. Radiofrequency (RF) of I-PA seems to be an excellent alternative to hemithyroidectomy for these patients. The present study aimed to report three cases of PHPT and I-PA treated with RF at two institutions. Materials and methods These two institutions share guidelines for thyroid RF. At both institutions, cases with surgical indication and difficult PA localization are discussed during thyroid multidisciplinary meetings involving all disciplines involved in managing these cases. RF was performed using a Viva RF System generator (STARMED). Ultrasound contrast evaluation was performed using a SonoVue (Bracco). All patients were followed-up by an expert endocrinologist. Results Three cases had indications for treating I-PA. All patients were proposed to undergo RF rather than hemithyroidectomy, and accepted this option. RF of I-PA was performed with a power of 30–50 W and delivering a total between 0.02 and 0.69 Kcal. The active treatment lasted just more than 1 min. Post-treatment follow-up revealed PTH and calcium normalization. Conclusion This study showed highly encouraging results in favor of treating I-PA with RF.

A rare case of Intrathyroidal parathyroid adenoma causing refractory hypercalcaemia. A challenging diagnostic and therapeutic journey

A rare case of Intrathyroidal parathyroid adenoma causing refractory hypercalcaemia. A challenging diagnostic and therapeutic journey

Brown tumor due to primary hyperparathyroidism in a familial case: a case report

BackgroundPrimary hyperparathyroidism (PHPT) is an uncommon disorder characterised by hypercalcemia with an increased parathyroid hormone level. We reported a PHPT familial case with two subjects, a father and a daughter, and both of them had suffered from the brown tumor.Case presentationThe proband, a 43-year-old patient, developed parathyroid adenomas at the age of 15; a histologically confirmed right parathyroid adenoma was removed by parathyroidectomy; and after six months follow-up, the serum calcium level was normalised. At the age of thirty-three, a CT scan of his head and neck revealed a mass in the right maxilla, as well as PHPT (i.e., left inferior parathyroid adenoma). Then, he underwent a biopsy of an exophytic lesion in the right maxilla and was diagnosed by pathology as a brown tumor, with the serum calcium and PTH levels at 2.78 mmol/L and 221 pg/mL, respectively. Subsequently, the patient took a left inferior parathyroid microwave ablation with ultrasound guidance. After three months of follow-up, the serum calcium and PTH levels returned to normal, and the brown tumor was resolved. After three years, it mineralised as revealed in a CT scan. By the time he was 43 years old, during the 28-year follow-up period, the serum calcium and PTH levels were still within the normal range, and there was no discomfort reported. He has consistently taken calcium supplements throughout the 28 years. Since the initial diagnosis, his blood indicators of kidney function have been normal, and ultrasound showed renal calculus in the right kidney and a normal left kidney. The proband’s daughter, a 15-year-old girl, experienced left upper extremity pain for ten months. CT scan revealed a mass in the distal left radius, and a giant cell tumor was suspected. A surgical internal fixation was performed, and the pathology showed a brown tumor. Laboratory tests revealed a serum parathyroid hormone (PTH) level of 1554pg/mL, calcium level of 3.14 mmol/L, phosphorus level of 0.72 mmol/L, and alkaline phosphatase level of 1892 U/L. Given the osteitic changes and elevated levels of calcium and PTH, ultrasonography was performed, after which a mass was detected measuring 19 × 9 × 7 mm mixed with solid components and cystic fluid in the right thyroid gland. The results of 99mTc-MIBI scintigraphy confirmed the abnormal accumulation of 99mTc-MIBI in the right thyroid gland but not seen in the bilateral parathyroid glands. The patient underwent thyroidectomy, and the postoperative pathology report indicated an intra-thyroid ectopic parathyroid adenoma. The serum calcium and PTH levels became normal at 4 h after surgery. One to three months after operation, the serum calcium level was low, while the serum PTH level was high. Then, the patient was advised to take calcium supplements. Until the sixth month after the operation, the serum calcium level and serum PTH level returned to normal, and the bone pain was relieved. The patient’s blood tests for kidney function remained normal. There was no evidence of bilateral kidney disease (such as nephrolithiasis or nephrocalcinosis) detected by ultrasound scan. There were several similarities in the state of illness between these two subjects. Both the father and the daughter developed parathyroid adenomas at the age of 15, and there was no lesion in other endocrine glands. And genetic testing revealed mutations in the CDC73 genes in both father and daughter. On the other hand, there were also a few differences. The father’s first signs of brown tumor were in the right maxilla, while the daughter’s appeared in the distal left radius. The father presented pathological changes in the left and right parathyroid glands, whereas the daughter presented with an ectopic parathyroid adenoma in the right thyroid gland.ConclusionWe report a familial case in which father and daughter were diagnosed to have brown tumors due to parathyroid adenoma and ectopic parathyroid adenoma, and genetic testing revealed CDC73 gene mutations in both. Therefore, in the diagnostic and differential process of young patients having bone disease, clinicians should not only focus on the clinical manifestations of the skeleton, but also implement a comprehensive analysis of systemic symptoms, considering the possibility that the patient has familial PHPT.

SAT199 Intrathyroidal Parathyroid Adenomas: A Case Series

Abstract Disclosure: B.K. Bowens: None. D. LaChance: None. M.K. Shakir: None. T.D. Hoang: None. Background: Primary hyperparathyroidism (PHPT) is a relatively common condition which affects 1-7 people per 1000. However, intrathyroidal parathyroid adenomas (ITPA) have a prevalence of 1.3% to 6.7%. In this case series, we report 3 cases of ITPA. Case 1: 66-year-old male with a history of PHTP without intervention at initial diagnosis presented to Endocrinology several years after initial diagnosis due to an incidental thyroid nodule on routine CT lung cancer screening. Parathyroid hormone (PTH) level found to be 109.3 from a previous level of 80 (ref 10-55pg/mL) in the setting of mild hypercalcemia and osteopenia. Initial bedside thyroid ultrasound was suggestive of a right ITPA. Parathyroid scan, formal thyroid US and CT gated scan revealed a 1.5cm parathyroid adenoma (PA) posterior to the right superior aspect of the thyroid gland. Fine Needle Aspiration (FNA) was completed with PTH washout of 399.40 pg/mL. Right superior parathyroidectomy confirmed ITPA due to an intrathyroidal parathyroid adenoma Case 2: 44-year-old female presented with 9 months of fatigue and was diagnosed with PHPT. Her PTH level was 167 with a serum calcium of 10.9 (ref 8.5-10.4 mg/dL). CT SPECT with tech-99M sestamibi was positive for a right parathyroid adenoma. Explorative surgery did not localize parathyroid adenoma. Thyroid ultrasound revealed a 9mm hypoechoic lesion in the right inferior lobe with polar artery. FNA of this lesion was completed with PTH washout of 4737 pg/mL. Right hemi-thyroidectomy was completed with resolution of PHTP. Case 3: 54-year-old male with history of PHPT and carcinoma of the right kidney s/p nephrectomy presented with persistent hypercalcemia. Serum calcium of 10.2-11.0 mg/dL and PTH of 160-186 pg/mL. Thyroid US showed a 1.1cm hyperechoic, cystic nodule in the left inferior thyroid lobe. Sestamibi was consistent with ITPA. FNA of left thyroid mass with PTH washout of 2602 pg/mL. Parathyroidectomy with left thyroid lobectomy was completed with resolution of hypercalcemia. Discussion: PHPT is a common endocrinopathy with 85% of cases due to PAs, 15% due to parathyroid hyperplasia, and <1% due to carcinoma. ITPAs have an incidence of 1.3% to 6.7% and are due to improper embryologic migration. Sestamibi parathyroid scan allows for localization of PA and for minimally invasive procedures. Other imaging modalities include SPECT, US, SPECT-CT, and MRI. PTH washout with more than 101 pg/mL confirms the presence of parathyroid tissue or adenoma. Conclusion: This is a rare presentation of a common endocrinopathy. These patients were noted to have PHTP. Initial exploratory neck dissections did not localize. FNA and US were able to confirm IPTAs and hemi-thyroidectomy was needed for definitive management with resolution of PHTP. Presentation: Saturday, June 17, 2023

FRI691 Intrathyroidal Parathyroid Adenoma With Congenitally Absent Contralateral Thyroid Lobe Treated With Thermal Ablation

Abstract Disclosure: L. Bilandzic: None. L. Bilandzic: None. H. Korkusuz: None. We present a rare case of primary hyperthyroidism with ectopic adenoma located in the right thyroid lobe with congenitally absent left thyroid lobe which was treated with thermal ablation. A 60-year-old woman was referred to endocrinology clinic for further evaluation of her elevated total serum calcium of 11.4 mg/dL (reference range 8.5-10.5), elevated parathyroid hormone (PTH) level of 106 (10-60 pg/mL). Bone mineral densitometry showed a total T score of -2.9 in L1-L4. Other results were vitamin D 25-OH 30 ng/mL (ref. range 30 - 100), TSH 3.36 µIU/mL (ref range 0.4-5.0), eGFR 83 (normal > 59 mL/min/ 1.73 m²). She was asymptomatic and had no history of kidney stones. Other causes of hypercalcemia were refuted. Given the osteoporosis in her lumbar spine, parathyroid localization and surgery were suggested. Thyroid and parathyroid sonography demonstrated a solid hypoechoic nodule in the right thyroid lobe, 12x10x11mm, with smooth margins, no calcifications, classified as ACR TI-RADS T4. Left thyroid lobe was not appreciated and was considered to be congenitally absent since the patient did not have a history of a previous thyroid resection. Further localization studies (99mTc Sestamibi parathyroid scintigraphy and 4D-CT of the neck) did not reveal any other possible candidates for parathyroid adenomas. Eventually, a fine needle aspiration of the nodule in the right thyroid lobe was performed. PTH needle wash showed a PTH value of 633 pg/mL whereas the PTH value ≥ 100 pg/mL is suggestive of the presence of PTH secreting tissue. Given the thyroid anatomy found with this patient, a right lobe hemithyroidectomy would result with a permanent substitution dependent hypothyroidism. As an alternative, thermal ablation was presented as a treatment option for which the patient opted. She underwent the procedure in local anesthesia. Sonographic imaging of the adenoma was followed by the percutaneous insertion of the coagulation electrode. The utilized high frequency ablator was used with an output of 9 to 40 W and a frequency of 470 ± 10 kHz. There were no complications developed during or after the procedure. Two weeks after the thermal ablation, PTH level was measured at 55 pg/mL, total serum calcium at 9.5 mg/dL, TSH 1.01 µIU/mL. Sonography showed a hyperechoic nodule at the former location of the parathyroid adenoma, which was evaluated as a scar tissue. Three months after the procedure total calcium was at 9.3 mg/dL, PTH at 58 pg/mL, hence no biochemical evidence of pHPT. This is a rare case of ectopic parathyroid adenoma located in the thyroid gland with hemi agenesis of the contralateral lobe. A minimally invasive thermal ablation was performed with the goal of inactivation of the adenoma and preserving the euthyroid function. Presentation: Friday, June 16, 2023

WTP2.3 Incidence of intrathyroid parathyroid adenoma - last 9 years in a teaching hospital

Abstract Aim The incidence of intrathyroid parathyroid adenoma (iTPA) is estimated to be 0.7-5.7% of hyperparathyroidism cases. Thyroid lobectomies may be performed when an adenoma cannot be clearly identified and isolated. We aimed to review the incidence of iTPA and outcomes after surgery within our practice. Methods We retrospectively reviewed consecutive parathyroidectomies performed by two experienced upper gastrointestinal surgeons (VS and PT) in a teaching hospital between April 2013 and December 2022. Preoperative radiological imaging was reviewed, and cases of iTPAs were diagnosed intraoperatively and on histopathology. These were further evaluated to review the outcomes after surgery. Results Total of 211 parathyroidectomy surgeries were performed, 11 (5.2%) of which were found to be iTPAs. These were confirmed on histopathology. Median age of patient cohort was 57±13 years. Patients were predominantly female (n=10, 90.9%). None underwent previous neck exploration. There was radiological (SPECT and Ultrasound) suspicion of iTPAs in 3 (1.4%) cases; peri-operative decision was made to explore for iTPA in the remaining 8 cases. 9/11 (81.8%) patients had hemithyroidectomy performed; in the remaining two cases, adenoma was successfully isolated from thyroid tissue and resected. Preoperative methylene blue infusion was utilised in all cases, of which uptake was evident in 8 (72.7%) cases. Calcium normalised in all patients postoperatively and none required further neck exploration. Conclusion Our 9-year series of parathyroid surgery revealed 5.2% incidence of iTPA, the majority of which was diagnosed intraoperatively. Diagnosis of iTPA should be considered if there is suspicion on radiological imaging and where no obvious adenoma is identified after full neck exploration.

A Case of Intra-thyroidal Parathyroid Adenoma Confirmed by Intraoperative Near-infrared Autofluorescence

In general, the anatomical location and number of parathyroid glands are well known, but they are often found in a variety of locations, making it difficult to find parathyroid glands during surgery. Besides Intra-thyroidal parathyroid adenoma is extremely rare case, and it is harder to identify in surgery. We encountered a 51-year-old patient with a thyroid nodule. The results of the additional blood test and the Tc-99m MIBI were combined to determine that the left lower lobe parathyroid adenoma was highly likely. This patient was treated with left thyroid lobectomy with parathyroid identification using Near-infrared (NIR) imaging. Afterwards, the biopsy confirmed that it was a parathyroid adenoma, and has since been monitored through outpatient observation without any problem. We present this rare case with a review of related literatures.

Intra-thyroid parathyroid adenoma: a difficult task to find

We report a case of 66-year-old female, who presented with features of hypercalcemia and developed acute kidney injury (AKI). Parathyroid hormone level was raised up to 740 pg/ml. Ultrasound and sestamibi scan suggested presence of a right sided parathyroid adenoma. A decision of right sided parathyroidectomy was taken. The sample that was sent for frozen section showed only thyroid tissue. No macroscopically visible or palpable nodule suspected to be parathyroid adenoma could be found. So, a decision of right hemithyroidectomy was taken and done accordingly. On routine histopathology a solid gray white nodule was found within thyroid tissue and it was confirmed microscopically as parathyroid adenoma. BIRDEM Med J 2023; 13(2): 116-118

AIUM Practice Parameter for the Performance and Interpretation of Diagnostic Ultrasound of the Thyroid and Extracranial Head and Neck.

AIUM Practice Parameter for the Performance and Interpretation of Diagnostic Ultrasound of the Thyroid and Extracranial Head and Neck.

A rare case of intrathyroidal cystic parathyroid adenoma

Cystic parathyroid adenomas are rare causes of primary hyperparathyroidism, representing about 1–2% of cases.1 Even rarer are cystic ectopic intrathyroidal parathyroid adenomas, with only eight cases in reported literature.1 Due to its rarity, it is rarely considered as a differential diagnosis on imaging, fine needle aspiration and macroscopic examination of the thyroid. We report a case for a 79-year-old female patient who presented with primary hyperparathyroidism and left thyroid nodule. The patient initially underwent fine needle aspiration for the nodule which was designated a Bethesda Category 3 result.

Oral kavitede kitle ve eşlik eden insidental papiller tiroid karsinomu ile başvuran normokalsemik primer hiperparatiroidizm olgusu

Hyperparathyroidism (HPT) is an endocrine disorder characterized by high secretion of parathyroid hormone. Brown tumor is one of the skeletal manifestations of HPT. Its overall prevalence is low (about 0.1%). Involvement of facial bones is extremely rare. The mandible is involved in 4.5% of cases. Primary HPT (PHPT)with vitamin D deficiency worsens the clinical course. Parathyroid adenoma is detected in ectopic places with a rate of 8.5%. 0.2% is intrathyroidal, 2% is located in different neck regions, 4.1% is in the upper mediastinum, and 2.2% is in the lower mediastinum. The prevalence of papillary thyroid cancer (PTC) in PHPT patients has been reported to range from 2% to 15%. In the literature, incidentally detected papillary thyroid cancer in patients with hyperparathyroidism was detected in patients who underwent total thyroidectomy associated with intrathyroidal parathyroid adenoma.
 In this article, we present a case of incidental papillary thyroid carcinoma with ectopic parathyroid adenoma accompanied by severe vitamin D, and diagnosed during accompanying surgery following a brown tumor was considered after primary hyperparathyroidism was detected. However, the patient was admitted with a mass in the oral cavity, diagnosed before as a pyogenic granuloma with a delayed diagnosis without considering brown tumor because it was normocalcemic. It is the first case in the literature of papillary thyroid carcinoma detected incidentally with ectopic parathyroid adenoma in the thyrothymic region.

Intrathyroidal parathyroid adenomas: Scoping review on clinical presentation, preoperative localization, and surgical treatment.

Intrathyroidal parathyroid adenomas (IPAs) are a rare cause of primary hyperparathyroidism. They are often difficult to localize preoperatively and intraoperatively, making diagnosis and treatment challenging. Current data on IPAs are sparse and fragmented in the literature. This makes it difficult to compare the effectiveness of different imaging and surgical techniques. To address this issue, this scoping review maps the literature on IPAs, focusing on four domains: clinical presentation, current localization methods, different surgical techniques, and histopathological features. A search of MEDLINE, Embase, and the Cochrane Library was conducted, with 19 studies meeting the inclusion criteria. The characteristics of IPAs on ultrasound, fine-needle aspiration, CT, MRI, sestamibi-based techniques, and selective venous sampling are summarized. Emerging imaging modalities, including autofluorescence, are introduced. Surgical methods and intraoperative factors that correlate with high success rates for removal are highlighted. This review also identifies gaps in knowledge to guide further research into this area.

An Interesting Case of Hypercalcemia: Intrathyroidal Parathyroid Adenoma

Hyperparathyroidism is the most common cause of hypercalcemia in the general population, with most patients presenting with mild to moderate hypercalcemia on routine bloodwork. Serum parathyroid hormone levels, followed by neck imaging studies, are helpful in diagnosing and localizing parathyroid adenomas. Ectopic parathyroid adenoma causes diagnostic challenges. Here, we present the patient case of a 65-year-old man with severe and symptomatic hypercalcemia who was found to have an intrathyroidal parathyroid adenoma, confirmed only after thyroid resection. Although imaging and laboratory results were helpful in our evaluation, pathology was the key to establishing the final diagnosis.

PSAT213 Intrathyroidal Parathyroid Adenoma Diagnosed on Thyroseq v2

Abstract Background The incidence of intrathyroidal parathyroid adenoma varies from <1% to 6% and can be a diagnostic dilemma. Intrathyroidal parathyroid adenomas can have suspicious sonographic features that prompt fine needle aspiration (FNA) to evaluate for thyroid cancer. Differentiation between thyroid and parathyroid tissue on cytology can be difficult, and these lesions may be diagnosed as indeterminate thyroid nodules. Molecular testing is a useful adjunct that allows for identification of parathyroid adenomas in this setting. Clinical Case A 59-year-old female with osteopenia and a recent history of traumatic vertebral fracture presented for workup of asymptomatic hypercalcemia. Labs showed intact parathyroid hormone (iPTH) 168 pg/mL (reference 11-51 pg/mL), serum total calcium 12.2 mg/dL (reference range 8.6-10.4 mg/dL), albumin 4.7 g/dL (reference 4.1-5.3 g/dL), phosphorus 2.1 mg/dL (reference 2.3-4.4 mg/dL), creatinine 0.7 (reference 0.6-1.3 mg/dL), and 25-OH vitamin of 28 ng/mL (reference 20-50 ng/mL). Cervical ultrasound showed a 2.1 cm hypoechoic left thyroid nodule. Subsequent 99mTc-Sesatmibi scan showed increased tracer retention in the left posterior thyroid lobe. FNA of the left thyroid nodule was performed with cytology showing follicular lesion of undetermined significance (FLUS). Molecular testing with Thyroseq v2 showed parathyroid tissue consistent with intrathyroidal parathyroid adenoma. The patient underwent successful left thyroid lobectomy with removal of an intrathyroidal parathyroid gland, with subsequent decrease of iPTH to 44 pg/mL (reference 11-51 pg/mL) and total serum calcium to 9.5 mg/dL (reference 8.6-10.4 mg/dL). Surgical pathology confirmed parathyroid adenoma. Discussion Due to the ubiquity of thyroid FNAs to rule out malignancy, there has been a rise in the number of incidental parathyroid gland aspirations. Thyroid lesions with diagnosis of FLUS or oncocytic features are prone to misdiagnosis due to similarities in morphologic overlap and anatomic proximity. Molecular testing such as Thyroseq v2 routinely tests for PTH and can identify parathyroid tissue in lesions initially diagnosed as indeterminate thyroid nodules. Newer molecular test versions including ThyroSeq v3 similarly have high analytical accuracy in detecting thyroid cancer and parathyroid lesions. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Radiofrequency Ablation Is a Thyroid Sparing Treatment Option for Primary Hyperparathyroidism Caused by an Intrathyroidal Parathyroid Adenoma

Radiofrequency Ablation Is a Thyroid Sparing Treatment Option for Primary Hyperparathyroidism Caused by an Intrathyroidal Parathyroid Adenoma

Distinguishing Intrathyroid Parathyroid Adenoma from Colloid Nodules and Papillary Thyroid Carcinomas Using Multiphasic Multidetector Computed Tomography.

The aim of the study is to determine whether multiphase multidetector computed tomography (4D-MDCT) can differentiate between intrathyroid parathyroid adenomas (ITPAs), colloid nodules, and papillary thyroid carcinoma (PTC). We studied 22 ITPAs, 22 colloid nodules, and 11 PTCs in 55 patients. Hounsfield unit (HU) values of the nodules were measured on 4D-MDCT in the precontrast, arterial, venous, and delayed phases. Raw HU values, phase with peak enhancement, and washout percentages between the phases were evaluated. Regardless of size, all ITPAs (22/22) showed peak enhancement in the arterial phase, which was significantly greater than both colloid nodules (15/22) and PTC (6/11, P = 0.002); thus, nodules with peak enhancement in the venous or delayed phase were not ITPAs (specificity = 1). For nodules with peak enhancement in the arterial phase, the percentage washout in the arterial-to-venous phases separated ITPAs from PTC and colloid nodules (P < 0.001) with greater than or equal to 23.95% loss of HU value implying IPTA (area under curve, 0.79). This left a subset of colloid nodules or PTC that either peaked in the venous or delayed phase or had an arterial-to-venous phase washout of less than 23.95%. From this subset, PTC measuring 1 cm or greater could be separated from colloid based on HU values in the arterial phase with a cutoff HU value less than 81.4 for PTC (area under curve, 0.72) and an HU value greater than 164.5 suggested colloid. Intrathyroid parathyroid adenomas can be distinguished from colloid nodules and PTC by peak enhancement in the arterial phase and rapid washout. A subset of colloid and PTC measuring 1 cm or greater can be separated using arterial phase HU values.

Diagnosis of Ectopic Intrathyroidal Parathyroid Adenoma with Nodular Goiter by 18F Fluorocholine: A Case Report.

The occurrence of ectopic intrathyroidal parathyroid adenoma (EPTA) is very rare, which causes some difficulties in diagnosis and complicates treatment. In addition, the occurrence of EPTA with nodular goiter (NG) is rare, which makes diagnosis difficult and requires the assistance of clinical evidence, imaging data, and cytological examination results. Therefore, we present a patient with a final diagnosis of ETPA with NG.

Intrathyroidal Parathyroid Adenomas in Primary Hyperparathyroidism: Clinical and Imaging Findings.

ObjectivesPrimary hyperparathyroidism (PHPT) is a common endocrine disease. Ectopic adenomas may cause a failed surgery which results in persistence or recurrence. Intrathyroidal parathyroid adenoma (ITPA) is a rare reason for PHPT and site of ectopia. Herein, we aimed to investigate the clinical and imaging features of patients with ITPAs and the effectiveness of radiological tools for localization at a tertiary reference center.MethodsThe files of 708 consecutive patients who underwent parathyroidectomy for PHPT in our department between January 2007 and December 2021 were investigated retrospectively. PHPT patients with ITPA were included in the study. Patients with missing data were excluded from the study. Clinicopathological features of the patients and radiological evaluation findings were investigated.ResultsTwenty-eight (28/708: 3.9%) patients were included in the study. The complete intrathyroidal gland and subcapsular parathyroid gland were observed in 8 (1.1%) and 20 (2.8%) patients, respectively. The ultrasound and parathyroid scintigraphy revealed the accurate localization of ITPA in 25 (89.3%) and 18 (64.3%) patients, respectively. Additional imaging modalities were applied for 10 patients in which conventional localization studies were discordant or inconclusive. ITPAs were most commonly found in the lower gland (n=20) localization. All patients had a successful parathyroidectomy and neither persistence nor recurrence was occurred in the study group.ConclusionThe ITPAs are rare in PHPT. The ultrasound has a high diagnostic rate in experienced hands. The second-line imaging methods may be favorable in the presence of negative or discordant scans. The pre-operative localization studies can detect the ITPAs in most patients, so blind thyroidectomy should be avoided.

Hyperparathyroidism caused by intrathyroidal parathyroid adenoma detected by 99mTc-sestamibi parathyroid scan and 18F-Fluorocholine PET/CT.

Hyperparathyroidism caused by intrathyroidal parathyroid adenoma detected by 99mTc-sestamibi parathyroid scan and 18F-Fluorocholine PET/CT.