Primary hyperparathyroidism caused by a tiny mediastinal parathyroid adenoma with non-localising imaging studies.

Variations in parathyroid gland positions often cause failure in initial parathyroid adenoma surgery, especially when imaging fails to localise the adenoma. This report describes a female patient with primary hyperparathyroidism for which preoperative localisation studies did not determine the position of the hyperfunctioning gland. The initial approach with bilateral cervical exploration and intraoperative parathyroid hormone monitoring was performed unsuccessfully. A mediastinal adenoma was suspected due to meticulous negative neck exploration and repeated negative images for a neck adenoma. Subsequently, a second approach involving mediastinal exploration was performed. After the removal of remnant thymic tissue in the mediastinal space, a significant drop in intraoperative parathyroid hormone levels was achieved. The pathological result confirmed the presence of a tiny pathological parathyroid adenoma within the thymus. At 6 months follow-up, postoperative biochemical assessment was consistent with normal calcium and parathyroid hormone levels.

Aortic root dilation in acromegaly.

Previous studies have linked persistent elevations in growth hormone (GH) and insulin-like growth factor-1 (IGF-1) to cardiac abnormalities including aortic root dilation. Guidelines in the management of this dilation below the size recommended for surgery have not been well defined but follow-up and intervention when appropriate could be life-saving. We report the case of a man in his 60s who had been living with undiagnosed acromegaly for many years. His initial assessment through point-of-care ultrasound raised concerns about potential cardiac enlargement, prompting further investigation with a formal echocardiogram, which revealed a significant aortic root dilation measuring 4.5 cm. Subsequent blood tests confirmed elevated levels of IGF-1. Brain MRI showed a focal lesion in the pituitary gland, which was surgically resected, confirming the diagnosis of a GH-secreting pituitary adenoma. One year after surgery, a repeat CT angiogram of the chest demonstrated a stable size of the aortic root aneurysm.

ENDOANGEL improves detection of missed colorectal adenomas in second colonoscopy: A retrospective study.

The ENDOANGEL (EN) computer-assisted detection technique has emerged as a promising tool for enhancing the detection rate of colorectal adenomas during colonoscopies. However, its efficacy in identifying missed adenomas during subsequent colonoscopies remains unclear. Thus, we herein aimed to compare the adenoma miss rate (AMR) between EN-assisted and standard colonoscopies. Data from patients who underwent a second colonoscopy (EN-assisted or standard) within 6 months between September 2022 and May 2023 were analyzed. The EN-assisted group exhibited a significantly higher AMR (24.3% vs 11.9%, P = .005) than the standard group. After adjusting for potential confounders, multivariable analysis revealed that the EN-assisted group had a better ability to detect missed adenomas than the standard group (odds ratio = 2.89; 95% confidence interval = 1.14-7.80, P = .029). These findings suggest that EN-assisted colonoscopy represents a valuable advancement in improving AMR compared with standard colonoscopy. The integration of EN-assisted colonoscopy into routine clinical practice may offer significant benefits to patients requiring hospital resection of lesions following adenoma detection during their first colonoscopy.

Clinical, Pathological and Endoscopic Features of Neoplastic or Non-neoplastic Reddish Depressed Lesions after Helicobacter pylori Eradication.

BACKGROUND AND AIMS: Early gastric cancers (EGCs) after Helicobacter pylori (H. pylori) eradication often appear as reddish depressed lesions (RDLs); the same features are also appeared in benign stomachs after eradication. We compared clinic-pathological and endoscopic features of benign and neoplastic RDLs after H. pylori eradication. METHODS: 228 neoplastic RDLs after H. pylori eradication were studied. All lesions were divided into neoplastic RDLs (differentiated carcinoma or adenoma, n=114) and benign RDLs (n=114) according to the histology. Clinical and pathological characteristics were compared in neoplastic and benign groups. Endoscopic diagnostic yields using the white light (WL) endoscopy, chromoendoscopy (CE) using indigo carmine dye and the magnifying endoscopy with narrow-band imaging (ME-NBI) were also evaluated in relation to the pathological diagnosis. RESULTS: Size of neoplastic RDLs was larger than that of benign RDLs (p<0.01). Sensitivity, specificity and accuracy for predicting pathological types of RDLs was 70.1%, 52.6% and 61.4% for the WL, 65.8%, 63.1% and 65.4% for the CE, while the ME-NBI scored better with the 88.6%, 88.6%, 99.1% and 93.9% of sensitivity, specificity and accuracy. The accuracy of the ME-NBI was 99.9% (113/114) in the benign RDLs and 89.4% (101/114) for the neoplastic RDLs. Undiagnosed neoplastic RDLs using the ME-NBI were associated with more differentiated tumors such as adenoma and well-differentiated adenocarcinoma (tub1) and the presence of an unclear demarcation line. CONCLUSIONS: ME-NBI is useful to diagnose RDLs after H. pylori eradiation, while some of neoplastic lesions are difficult to diagnose using the ME-NBI.

Predictive value of 18F-fluorodeoxyglucose PET/CT in histological grade of incidental colorectal adenoma.

BACKGROUND: 18F-fluorodeoxyglucose (18F-FDG) positron-emission tomography/computed tomography (PET/CT) as an imaging modality for the whole body has shown its value in detecting incidental colorectal adenoma. In clinical practice, adenomatous polyps can be divided into three groups: low-grade intraepithelial neoplasia (LGIN), high-grade intraepithelial neoplasia (HGIN) and cancer, which can lead to different clinical management. However, the relationship between the 18F-FDG PET/CT SUVmax and the histological grade of adenomatous polyps is still not established, which is a challenging but valuable task. METHODS: This retrospective study included 255 patients with colorectal adenoma (CRA) or colorectal adenocarcinomas (AC) who had corresponding 18F-FDG uptake incidentally found on PET/CT. The correlations of SUVmax with pathological characteristics and tumor size were assessed. Neoplasms were divided into LGIN, HGIN, and AC according to histological grade. Receiver operating characteristic (ROC) analysis was applied to evaluate the predictive value of the SUVmax-only model and comprehensive models which were established with imaging and clinical predictors identified by univariate and multivariate analysis. RESULTS: The SUVmax was positively correlated with histological grades (r=0.529, P<0.001). Univariate and multivariate analysis showed that SUVmax was an independent risk factor among all groups except between HGIN and AC. The area under the curves (AUCs) of the comprehensive model for distinguishing between AC and adenoma, LGIN and HIGN, LGIN and AC, and HGIN and AC were 0.886, 0.780, 0.945, 0.733, respectively, which is statistically higher than the AUCs of the SUVmax-only model with 0.812, 0.733, 0.863, and 0.688, respectively. CONCLUSIONS: As an independent risk factor, SUVmax based on 18F-FDG PET/CT is highly associated with the histological grade of CRA. Thus, 18F-FDG PET/CT can serve as a noninvasive tool for precise diagnosis and assist in the preoperative formulation of treatment strategies for patients with incidental CRA.

Hemorrhagic adenoma mimicking anterior communicating artery aneurysm. / Adenoma hemorrágico que imita a un aneurisma de la arteria comunicante anterior.

TITLE: Adenoma hemorrágico que imita a un aneurisma de la arteria comunicante anterior.

Standard-definition White-light, High-definition White-light versus Narrow-band Imaging Endoscopy for Detecting Colorectal Adenomas: A Multicenter Randomized Controlled Trial.

OBJECTIVE: This study aimed to compare the performance of standard-definition white-light endoscopy (SD-WL), high-definition white-light endoscopy (HD-WL), and high-definition narrow-band imaging (HD-NBI) in detecting colorectal lesions in the Chinese population. METHODS: This was a multicenter, single-blind, randomized, controlled trial with a non-inferiority design. Patients undergoing endoscopy for physical examination, screening, and surveillance were enrolled from July 2017 to December 2020. The primary outcome measure was the adenoma detection rate (ADR), defined as the proportion of patients with at least one adenoma detected. The associated factors for detecting adenomas were assessed using univariate and multivariate logistic regression. RESULTS: Out of 653 eligible patients enrolled, data from 596 patients were analyzed. The ADRs were 34.5% in the SD-WL group, 33.5% in the HD-WL group, and 37.5% in the HD-NBI group (P=0.72). The advanced neoplasm detection rates (ANDRs) in the three arms were 17.1%, 15.5%, and 10.4% (P=0.17). No significant differences were found between the SD group and HD group regarding ADR or ANDR (ADR: 34.5% vs. 35.6%, P=0.79; ANDR: 17.1% vs. 13.0%, P=0.16, respectively). Similar results were observed between the HD-WL group and HD-NBI group (ADR: 33.5% vs. 37.7%, P=0.45; ANDR: 15.5% vs. 10.4%, P=0.18, respectively). In the univariate and multivariate logistic regression analyses, neither HD-WL nor HD-NBI led to a significant difference in overall adenoma detection compared to SD-WL (HD-WL: OR 0.91, P=0.69; HD-NBI: OR 1.15, P=0.80). CONCLUSION: HD-NBI and HD-WL are comparable to SD-WL for overall adenoma detection among Chinese outpatients. It can be concluded that HD-NBI or HD-WL is not superior to SD-WL, but more effective instruction may be needed to guide the selection of different endoscopic methods in the future. Our study's conclusions may aid in the efficient allocation and utilization of limited colonoscopy resources, especially advanced imaging technologies.

Esophageal schwannoma mimicking non-functional parathyroid adenoma on 99mTc-sestamibi imaging: a case report.

Technetium-99m sestamibi single-photon emission computed tomography/computed tomography (99mTc-sestamibi SPECT/CT) is a mainstay of the pre-operative localization of parathyroid lesions. We report here the case of a 30 year-old woman with a fortuitously discovered 2 cm cervical mass for which a parathyroid origin was originally suspected due to its retro-thyroidal localization and a personal history of nephrolithiasis. Normal serum calcium and parathyroid hormone (PTH) levels excluded primary hyperparathyroidism, raising suspicion of a non-functional parathyroid adenoma, and SPECT/CT imaging showed that the mass was 99mTc-sestamibi-avid. Fine-needle aspiration (FNA) was performed; cytology was non-diagnostic but the needle washout was negative for thyroglobulin, calcitonin and PTH, arguing against a thyroidal or parathyroidal origin of the mass. Core needle biopsy revealed a schwannoma, ostensibly originating from the recurrent laryngeal nerve; upon surgical resection, it was finally found to arise from the esophageal submucosa. This case illustrates the fact that endocrinologists, radiologists, nuclear medicine, head and neck, and other specialists investigating patients with cervical masses should be aware that schwannomas need to be considered in the differential diagnosis of focal 99mTc-sestamibi uptake in the neck region.

HOW I DO IT: Cushing's disease-selective adenomectomy via an endoscopic transsphenoidal approach.

BACKGROUND: An ACTH-secreting pituitary adenoma is the most common cause of excessive endogenous glucocorticoid production resulting in Cushing's Syndrome. A multidisciplinary approach is paramount. Selective adenomectomy is the treatment of choice. METHOD: Endoscopic transnasal transsphenoidal approach to the tumour, along with techniques for resection, are demonstrated. CONCLUSION: Endoscopic transsphenoidal approaches with its magnified view of the pituitary gland allows precise microsurgical dissection during selective adenomectomy. This technique increases the possibility of proving a gross total resection, leading to clinical and biochemical cure in these patients.

Clinicoradiological Parameters and Biochemical and Molecular Alterations Predicting Remission and Recurrence After Surgical Treatment of Corticotroph Adenomas-Cushing Disease.

OBJECTIVE: Endonasal endoscopic transsphenoidal surgery (TSS) and resection of pituitary adenomas are considered the gold standard treatment for Cushing disease (CD). Even with various recent advances in management, disease persistence and recurrence are common in these patients. The remission rate in the global population after surgery has been reported to vary widely from 64% to 93%. This study aims to determine the various clinical, biochemical, radiological, and histological factors that correlate with persistence and recurrence in patients with CD. This study also aims to understand the clinicopathological significance of EGFR-MAPK, NF-κB, and SHH pathway activation and to study the protein expression of activation markers of these pathways (i.e., c-Fos, c-Jun, GLI-1, pMEK, NR4A1, and p44) in functioning corticotroph pituitary adenomas. METHODS: From January 2009 to September 2022, the clinical data of 167 patients who underwent surgical treatment (n = 174 surgeries) for CD with a median follow-up of 8.1 years (range, 1-13.29 years) were ambispectively analyzed. The preoperative clinical, biochemical, and radiological features, operative findings, postoperative clinical and biochemical data, and histopathological and molecular profiles were retrieved from the electronic medical records. The patients were followed up to assess their remission status. RESULTS: Among the 174 surgeries performed, 140 were primary surgeries, 22 were revision surgeries, 24 surgeries were for pediatric patients, and 12 surgeries were for patients with Nelson syndrome. In the primary surgery cohort, 74.3% were female, and the average age was 28.73 ± 10.15 years. Of the primary surgery cohort, 75% of the patients experienced remission compared with 47.4% after revision surgery. The remission rate for the pediatric patients was 55.5%. The postoperative day 1 plasma cortisol (P < 0.001; area under the curve, 0.8894; range, 0.8087-0.9701) and adrenocorticotropic hormone (P < 0.001; area under the curve, 0.9; range, 0.7386-1) levels were seen to be strong independent predictors of remission in the primary surgery cohort. The remission rate after endoscopic TSS was greater than that after microscopic TSS in patients undergoing primary surgery (81.08% vs. 57.14%; P = 0.008). The presence of adenoma on histopathological examination (HPE) was also a strong predictor of disease remission (P = 0.020). On stratifying by surgical approach and HPE, microscopically operated patients without histopathological evidence of adenoma had significantly higher odds of nonremission (odds ratio, 38.1; 95% confidence interval, 4.2-348.3) compared with endoscopically operated patients with adenoma found on HPE. A lower immunoreactivity score for NR4A1 was found to correlate with higher remission rates (P = 0.074). However, none of the molecular markers studied (i.e., c-Fos, c-Jun, GLI-1, pMEK, and p44) showed a significant correlation with the preoperative cortisol values. CONCLUSIONS: The remission rate after primary surgery is higher than that after revision surgery and is lower for pediatric patients than for adults. The postoperative day 1 plasma cortisol and adrenocorticotropic hormone levels are strong independent predictors of remission in the primary surgery cohort. An endoscopic approach with histopathological evidence of adenoma is associated with a higher remission rate; thus, endoscopy should be the approach of choice for these patients with the goal of identification of an adenoma on HPE.

Clinical predictors of negative/equivocal SPECT imaging outcomes in primary hyperparathyroidism: Factors calling for 18F-choline-PET.

PURPOSE: For minimally invasive surgery of parathyroid adenomas, exact localization diagnostics are essential. Main imaging modalities used for diagnostics are sonography, SPECT with/without CT (traditional imaging) and 18F-choline-PET. The aim of our study was to identify predictors for inconclusive SPECT imaging and subsequently determine in which cases 18F-choline-PET is needed. METHODS: Retrospective analysis of 138 patients with histologically confirmed primary hyperparathyroidism (pHPT). After sonography, patients underwent SPECT or SPECT/CT imaging, with subsequent 18F-choline-PET in cases of disconcordant results. Logistic regression analysis was used to identify clinical and laboratory factors predictive for negative SPECT results. RESULTS: Sensitivity rates for sonography, SPECT, SPECT/CT, and choline-PET were 47 %, 49 %, 71.7 %, and 97 %, respectively. Logistic regression revealed lower PTH levels (p < 0.001), presence of structural thyroid disease (p = 0.018), and negative sonography (p < 0.001) as predictive of negative/equivocal SPECT outcome. An additional traditional imaging CT scan to a SPECT enhanced detection odds, as did greater adenoma weight. Urolithiasis, osteoporosis, and calcium values as measurement of activity and duration of disease showed no significant association with the detection rate. Furthermore, our study demonstrated that 18F-choline-PET exhibited remarkable sensitivity in detecting adenomas among patients with negative/equivocal SPECT results. CONCLUSION: Our study reveals potential predictive factors for a negative/equivocal SPECT outcome in pHPT. Identifying these factors might allow minimizing futile SPECT examinations and perhaps encourage timely utilization of 18F-choline-PET imaging. Our study reinforces the clinical significance of 18F-choline-PET, especially in complex cases with disconcordant results by conventional parathyroid imaging methods.

Comparative analysis of intraoperative and imaging features of invasive growth in pituitary adenomas.

BACKGROUND: Most pituitary adenomas (PAs), also termed pituitary neuroendocrine tumors, are benign in nature and can be treated effectively by surgical resection, medical treatment, and in special cases by radiotherapy. However, invasive growth can be an important feature of a more aggressive behavior and adverse prognosis. The extension of PAs into the cavernous sinus can be categorized according to the Knosp criteria on magnetic resonance imaging (MRI). Comparative analyses of MRI features and intraoperative findings of invasive growth regarding different clinical factors are still scarce. MATERIALS AND METHODS: We performed a retrospective single-center analysis of 764 PAs that were surgically treated between October 2004 and April 2018. Invasive growth was assessed according to the surgical reports and preoperative MRI (Knosp criteria). Clinical data, such as patient age at diagnosis and gender, histopathological adenoma type, and extent of resection, were collected. RESULTS: Invasive features on MRI were seen in 24.4% (Knosp grades 3A-4, 186/764) of the cases. Intraoperatively, invasion was present in 42.4% (324/764). Complete resection was achieved in 80.0% of adenomas and subtotal resection, in 20.1%. By multivariate analysis, invasion according to intraoperative findings was associated with the sparsely granulated corticotroph (SGCA, P = .0026) and sparsely granulated somatotroph (SGSA, P = .0103) adenoma type as well as age (P = .0287). Radiographic invasion according to Knosp grades 3A-4 correlated with age (P = .0098), SGCAs (P = .0005), SGSAs (P = .0351), and gonadotroph adenomas (P = .0478). Both criteria of invasion correlated with subtotal resection (P = .0001, respectively). CONCLUSIONS: Both intraoperative and radiographic signs of invasive growth are high-risk lesions for incomplete extent of resection and occur more frequently in older patients. A particularly high prevalence of invasion can be found in the SGCA and SGSA types. Cavernous sinus invasion is also more common in gonadotroph adenomas. Usage of the Knosp classification is a valuable preoperative estimation tool.

[Intraductal radiofrequency ablation under endosonography and cholangioscopy for residual adenoma of the major duodenal papilla with intraductal component]. / Vnutriprotokovaya radiochastotnaya ablyatsiya pod kontrolem endosonografii i kholangioskopii pri rezidual'noi adenome bol'shogo sosochka dvenadtsatiperstnoi kishki s vnutriprotokovym komponentom. Obzor literatury.

All adenomas of the major duodenal papilla (MDP) require resection regardless of morphological structure due to high risk of malignancy. Currently, intraluminal endoscopic interventions are preferable for these adenomas. MDP neoplasms with intraductal spread (type III and IV) are of particular difficulty for endoscopic techniques. Intraductal radiofrequency ablation provides new opportunities for minimally invasive treatment of patients with MDP adenomas and intraductal component. A 72-year-old patient after previous endoscopic papillectomy for MDP adenoma admitted to the Vishnevsky National Research Medical Center of Surgery due to residual adenomatous growths within the papillectomy zone extending to the common bile duct throughout 13 mm. The patient underwent intraductal RFA under endosonography and cholangioscopy. Despite difficult localization of residual growths extending to the common bile duct, endosonography-guided intraductal RFA provided total destruction of residual tumor that was confirmed by cholangioscopy. Length of treatment was 4 months, relapse-free period - 10 months. Minimally invasive endoscopic technology for residual MDP adenoma provided good clinical results.

Papillary Thyroid Cancer, Small Cell Lung Cancer, and Parathyroid Adenoma Synchronously Visualized on 99m Tc-MIBI SPECT/CT in a Patient With Hyperparathyroidism : Comparison With 18 F-FDG PET/CT.

ABSTRACT: 99m Tc-MIBI scintigraphy is a nuclear medicine imaging modality commonly used for the preoperative localization of parathyroid adenomas in patients with hyperparathyroidism. In addition, 99m Tc-MIBI can also be used for imaging various tumors due to its unique mechanism of intracellular accumulation. Here, we introduced a case of a single 99m Tc-MIBI SPECT/CT simultaneously visualized two different malignant tumors, such as papillary thyroid cancer and small cell lung cancer, along with a parathyroid adenoma in a patient with hyperparathyroidism. The clinical usefulness of 99m Tc-MIBI SPECT/CT was also explored by comparing it with 18 F-FDG PET/CT among the three tumors.

Clinical presentation and surgical outcomes of very large and giant pituitary adenomas: 80 cases in a cohort study of 306 patients with pituitary adenomas.

PURPOSE: To identify differences in the presentation and surgical outcomes between very large (30-39 mm) and giant (≥ 40 mm) (LARGE group) pituitary adenomas (PAs) compared to the smaller group (< 30 mm) (non-LARGE group). METHODS: Eighty patients with very large (n = 44) or giant (n = 36) PAs and 226 patients in the non-LARGE group who underwent tumor resection by pituitary surgery between 2008 and 2023 were studied. Hormonal, radiological, ophthalmological, and pathological data, and surgical outcomes were evaluated. RESULTS: Preoperatively, patients of the LARGE group presented more frequently with visual impairment (82.5% vs. 22.1%, P < 0.001) and with pituitary apoplexy (15.0% vs. 2.7%, P < 0.001) than the non-LARGE group. Moreover, the LARGE group were more commonly associated with preoperative panhypopituitarism (28.8% vs. 6.2%, P < 0.001). This group presented cavernous sinus invasion more frequently (71.3% vs. 23.9%, P < 0.001). The non-LARGE group achieved surgical cure more often than the LARGE group (79.7% vs. 50.0%, P < 0.001), and the rate of major complications was higher in the latest (8.8% vs. 1.3%, P < 0.004). CONCLUSIONS: PAs ≥ 30 mm are most frequently accompanied by hormonal dysfunction, cavernous sinus invasion, and visual impairment. All this implies lower resection rates and higher postoperative complications than the smaller adenomas, posing a real surgical challenge.

Magnetic Resonance Imaging Features of the Sphenoid Sinus in Patients with Non-Functioning Pituitary Adenoma.

Background and Objectives: A magnetic resonance imaging (MRI) scan is part of the diagnostic protocol in pituitary adenoma patients. The goal of the present study is to present and analyse the MRI appearances of the sphenoid sinus (SS) in patients with non-functioning pituitary adenoma (NFPA). Materials and Methods: This is a retrospective case-control study conducted between January 2015 and December 2023 in a tertiary referral hospital. Forty NFPA patients were included in the study group, while the control group consisted of 30 age- and gender-matched cases. Results: The sellar type of SS pneumatization was the most frequently encountered pattern among both groups. The presence of the lateral recess of the SS, mucosal cysts, and sphenoethmoidal cells was similar in both patient groups. The proportion of patients with SS mucosal thickness greater than 3 mm was 42.5% in NFPA group and 3% in the control group, and this difference was statistically significant (p < 0.001). The space between the two optic nerves was significantly larger in the NFPA group as compared to the control group (p < 0.001). Conclusions: Our study was able to establish a statistically significant association between the presence of NFPA and both the thickening of the SS mucosa and increased space between optic nerves.

Ultrasonographic Detective Flow Imaging for Evaluating Parathyroid Adenoma in Patients with Primary Hyperparathyroidism.

BACKGROUND: Detective flow imaging (DFI) is a new imaging technology that displays low-velocity blood flow, which is difficult to visualize on conventional color Doppler ultrasonography (CDU). In this study, we compared the usefulness of DFI with that of CDU and methoxy-isobutyl-isonitrile (MIBI) scintigraphy for detecting parathyroid adenoma (PA) in patients with primary hyperparathyroidism (PHPT). METHODS: From March 2021 to March 2023, 87 PHPT patients underwent surgery, and 66 had a single PA. We performed preoperative conventional ultrasonography with CDU, MIBI scintigraphy, and DFI for 42 patients (5 males and 37 females; mean age: 61.6 ± 15.4 years). RESULTS: MIBI scintigraphy detected PA in 85.7% (36/42) patients, and both CDU and DFI detected PA in all patients. The rates of vascularity in PA detected by CDU and DFI were 71.4% (30/42) and 85.7% (36/42), respectively. Vascularity was detected by DFI in 6 patients who were negative for vascularity on MIBI scintigraphy. Furthermore, DFI detected blood supply in 6 of the 12 patients with undetectable blood supply on CDU. Fisher's exact test revealed that high or low blood flow, as determined by DFI, was significantly associated with detection of feeding vessels in PA by CDU (P < 0.001). CONCLUSIONS: DFI was useful for preoperative detection of PA blood flow.

Incidentally detected follicular thyroid carcinoma mimicking parathyroid adenoma on Tc-99m MIBI scan: A case report.

RATIONALE: Primary hyperparathyroidism, though relatively prevalent among endocrine disorders, affecting 1% of the general population, often presents diagnostic challenges. Given its potential to precipitate severe complications including nephrolithiasis and fractures, timely diagnosis, and effective management are crucial. PATIENT CONCERNS: A 38-year-old woman with hypercalcemia was referred to the Department of Nuclear Medicine for a Tc-99m MIBI scan. DIAGNOSES: Tc-99m MIBI scan showed focal increased uptake in the left thyroid gland area, initially suggesting a parathyroid adenoma. Further examination using SPECT/CT revealed a nodular lesion within the left thyroid gland showing high Tc-99m MIBI uptake. INTERVENTIONS: Left thyroid lumpectomy confirmed the lesion as follicular thyroid carcinoma. On the second Tc-99m MIBI scan conducted after total thyroidectomy, a parathyroid adenoma was eventually detected in the right lower area, enabling the subsequent appropriate treatment, a right lower parathyroidectomy. OUTCOMES: Thirteen days after the parathyroidectomy, serum levels of total calcium and parathyroid hormone returned to normal. Furthermore, bone mineral density evaluated using DEXA remained within the expected range for her age even after 14 months. LESSONS: When interpreting the Tc-99m MIBI scan, it is essential to keep in mind that various tumors rich in mitochondria, such as thyroid carcinoma, could show a high uptake of Tc-99m MIBI.