Co-existent parathyroid adenoma and thyroid carcinoma. Nonspecificity of dual tracer parathyroid imaging for parathyroid lesions

Dual tracer parathyroid imaging (DTPI) using Tc-99m and TI-201 has a reported sensitivity of 92% for the detection of parathyroid adenomas. A patient with biopsy-proven parathyroid adenoma as well as papillary thyroid carcinoma is presented. To date, this is the first such case ever to be reported and implies that DTPI, although a sensitive diagnostic modality for parathyroid adenoma detection, is not specific. The diagnosis of primary hyperparathyroidism has recently been established more frequently than in the past due to detection of elevated serum calcium levels on routine blood samples, relatively sensitive parathormone (PTH) assays, and noninvasive imaging modalities such as nuclear medicine, CT scanning, and ultrasonography. At our institution, we have successfully detected the location of parathyroid adenomas in many cases, using the dual tracer method with TI-201 and Tc-99m, confirmed at surgery. We present a case of primary hyperparathyroidism in which two distinct lesions were detected by nuclear imaging: one lesion was proven at surgery to be a parathyroid adenoma, while the other represented thyroid carcinoma.     

Papillary thyroid carcinoma associated with parathyroid adenoma detected by pertechnetate-MIBI subtraction scintigraphy

Two cases of papillary thyroid carcinoma coexisting with a parathyroid adenoma are reported. A double-tracer pertechnetate-MIBI subtraction scan combined with neck ultrasound correctly visualized the site of the parathyroid adenoma despite the presence of thyroid nodule(s) located in the opposite thyroid lobe in one case and in both thyroid lobes in the other case. In both patients, the papillary thyroid carcinoma was cold with Tc-99m pertechnetate and hot with MIBI. Total thyroidectomy and parathyroidectomy of a solitary parathyroid adenoma were performed in both patients. Pertechnetate-MIBI subtraction scanning associated with neck ultrasound appears to be a useful imaging technique to detect parathyroid adenoma before operation in patients with concomitant thyroid nodular disease. A MIBI-hot and Tc-99m pertechnetate-cold thyroid nodule can indicate the possible presence of a malignant lesion.     

Importance of radio-guided minimally invasive parathyroidectomy using hand-held gamma probe and low (99m)Tc-MIBI dose. Technical considerations and long-term clinical results.

AIM: (99m)Tc-MIBI radio-guided surgery results, obtained in a group of 141 patients with primary hyperparathyroidism (HPT), are reported. METHODS: All patients were preoperatively evaluated by a single day protocol based on double-tracer parathyroid scintigraphy and neck ultrasound, and then operated by the same surgical team. In 102 patients (72.3%) with a high scan/ultrasound probability of solitary parathyroid adenoma and normal thyroid gland, a minimally invasive radio-guided surgery was planned. In the other 39 patients (27.7%) with scan/ultrasound evidence of multi-glandular disease (n=8) or concomitant nodular goiter (n=31), the intraoperative gamma probe was used during a standard bilateral neck exploration. Intraoperative quick parathyroid hormone (PTH) levels were routinely measured. The minimally invasive radio-guided surgery technique we developed, consisted of: a) injection of a low 37 MBq (99m)Tc-MIBI dose in the operative theatre during anaesthesia induction, b) patient's neck scan with a hand-held gamma probe just before the surgical cut to localize the cutaneous projection of the parathyroid adenoma, c) intraoperative probe detection of the parathyroid adenoma and its removal through a small 2-2.5 cm skin incision. RESULTS: Minimally invasive radio-guided surgery was successfully performed in 99/102 patients (97.0%). The gamma probe was particularly useful in patients with an ectopic parathyroid adenoma in the upper mediastinum (n=11) or to the carotid bifurcation (n=1) or located deep in the neck (n=8). Minimally invasive radio-guided surgery was also obtained in 18/23 patients who had previously undergone thyroid/parathyroid surgery. The mean operative time for minimally invasive radio-guided surgery was 38 min. No major surgical complication was recorded. Conversion to bilateral neck exploration was required in only 3 cases because of intra-operative diagnosis of parathyroid carcinoma (n=2), and persistence of elevated quick PTH levels after removal of the preoperatively visualized parathyroid adenoma (n=1). Among patients treated by standard bilateral neck exploration, the gamma probe was useful in localizing a thymical enlarged parathyroid gland in 1 patient with multi-glandular disease, a parathyroid adenoma located deep in the neck in 4 patients with concomitant nodular goiter and an ectopic parathyroid adenoma to the carotid bifurcation in another. However, in some other patients with a parathyroid adenoma located near to the thyroid, it was difficult to intraoperatively distinguish the parathyroid adenoma from a MIBI avid thyroid nodule. CONCLUSION: It can be concluded that: (a) in primary HPT patients with high scan/ultrasound probability of solitary parathyroid adenoma and normal thyroid gland, the gamma probe appears to be an effective, rapid and safe technique to perform minimally invasive radio-guided surgery; b) a (99m)Tc-MIBI dose as low as 37 MBq appears to be adequate to successfully perform radio-guided surgery; c) the measurement of quick PTH is recommended during minimally invasive radio-guided surgery; d) minimally invasive radio-guided surgery can be performed also in HPT patients with previous parathyroid/thyroid surgery thus limiting surgical trauma; e) with the possible exception of parathyroid adenoma located in ectopic sites or deep in the neck, the gamma probe technique does not seem recommendable in HPT patients with concomitant nodular goiter.     

Multiple brown tumors simulating bone metastases: a case of parathyroid adenoma coexisting with papillary carcinoma of the thyroid

A 55-year-old man with multiple brown tumors who initially was thought to have multiple bone metastases is described. He had elevated parathyroid hormone levels and was referred to the nuclear medicine department, where a parathyroid adenoma was diagnosed. At surgery, abnormal lymph nodes were seen, which were found to contain metastatic thyroid papillary carcinoma cells. On further exploration, the patient's bone scintigraph revealed multiple sites of increased uptake but no bone abnormalities on whole-body iodine and Tc-99m MIBI scans.     

Use of SPECT with (99m)Tc-Sestamibi in a patient affected by laryngeal carcinoma and parathyroid adenoma

We report the case of a patient with a laryngeal carcinoma in whom asymptomatic hyperparathyroidism was also detected during the preoperative work-up. A planar (201)Thallium/(99m)Tc-pertecnetate subtraction scintigraphy was performed in order to locate the suspected parathyroid adenoma. The study showed a single area of increased (201)Thallium uptake just above the thyroid isthmus, likely due to the laryngeal tumor. The scintigraphic study was repeated using (99m)Tc-Sestamibi and (99m)Tc-pertechnetate and employing the SPECT technique. Both SPECT studies made it possible to identify correctly the parathyroid adenoma, located inferiorly and in a posterior position to the lower third of the right thyroid lobe. The laryngeal tumor and parathyroid adenoma could be excised in a single surgery session. This case is of interest due to the rarity of the coexistence of two neck tumors and the clear advantage shown by the SPECT technique with (99m)Tc-Sestamibi over the planar technique with 201Thallium.     

Serendipitous detection of metastatic thyroid cancer during I-123 Tc-99m sestamibi dual parathyroid imaging

Dual isotope parathyroid imaging performed on a 47-year-old man with known papillary thyroid cancer and biochemical hyperparathyroidism showed residual concentration of sestamibi consistent with a right inferior parathyroid adenoma. Subsequent thyroidectomy and parathyroidectomy was performed. Histology revealed a left superior parathyroid adenoma and normal right inferior parathyroid gland. Right inferior parathyroid adenoma on scintigraphy was, in fact, a cervical lymph node metastasis from the papillary thyroid carcinoma.     

High resolution MRI in the detection of an intrathymic parathyroid adenoma

The most common cause of primary hyperparathyroidism is parathyroid adenoma. Of these, up to 20% have been reported to be in ectopic locations. Multiple imaging techniques have been utilized in the detection of ectopic adenoma and are discussed. We report on a case of an intrathymic parathyroid adenoma that was detected through the novel use of a breast coil in performing a high resolution MRI. The accurate localization permitted minimally invasive surgery, obviating morbidity associated with a sternotomy.     

Successful localisation of parathyroid adenomata by thallium-201 and technetium-99m subtraction scintigraphy: description of an improved technique

An improved method for parathyroid scanning using thallium-201 and technetium-99m subtraction imaging is described. The technique successfully localised ten of eleven parathyroid adenomas confirmed at neck exploration. Two false-positive studies were encountered in patients with no adenoma at operation, probably due to thyroid nodules. The technique was less successful in identifying diffusely hyperplastic parathyroid glands and was negative in a single patient with recurrent, functional parathyroid carcinoma.     

原发性甲状旁腺机能亢进的外科治疗

总结了30例原发性甲状旁腺机能亢进患者的手术治疗经验。颈丛或全身麻醉下低领位切口，术中快速病理结果证实28例为甲状旁腺腺瘤，均单发性，其中2例异位于甲状腺内，1例异位于前上纵隔，单纯切除；增生1例，但仅1个旁腺受累，全切除；腺癌1例，侵及食管、气管，肿瘤及受累部分食管气管切除并气管切开。无手术并发症。25例随访8个月至19年，包括增生1例，症状改善无复发。腺癌患者带气管套管生存已4年。提示手术治疗原发性甲状旁腺机能亢进疗效确实，应首先；明确为腺瘤者可行单侧探查，即使腺癌也不要轻易放弃。     

Parathyroid adenoma imaged by gallium-67 citrate. A case report

A parathyroid adenoma imaged by Ga-67 citrate in a 17-year-old man with primary hyperparathyroidism and a palpable solid tumor in the neck is presented. Although preoperative examination and intraoperative findings suggested a parathyroid carcinoma, histologic studies showed a parathyroid adenoma with predominant chief cell type.     

A parathyroid cyst with adenoma on thallium-201/technetium-99m subtraction imaging

A case of a parathyroid cyst with adenoma was seen on Tl-201/Tc-99m subtraction imaging. The literature regarding parathyroid cysts and the subtraction technique for parathyroid adenoma imaging was reviewed.     

Parathyroid carcinoma visualized by gallium-67 citrate scintigraphy

An abnormal uptake of [67Ga]citrate by a palpable neck tumor was observed in a patient with primary hyperparathyroidism. The pathological diagnosis of the surgically resected specimen was parathyroid carcinoma invading the thyroid. The uptake was negative in nine patients with parathyroid adenoma. These results suggest that 67Ga scintigraphy may be useful to differentiate parathyroid carcinoma from benign parathyroid tumor.     

Current status of preoperative localization in primary hyperparathyroidism (author's transl)]

Since Seldinger demonstrated in 1953 parathyroid adenomas by arteriography, numerous localizing procedures have been advocated. Based on our experience with selective venous sampling for measurement of parathyroid hormone by radioimmunoassay, selective arteriography, pneumomediastinography and scanning with 75Se-selenomethionine, a survey on localization techniques used up to now is given and their value and applications are discussed. Preoperative localization of parathyroid tissue should be limited to patients with previous unsuccessful surgery. In these cases we perform selective venous sampling following selective arteriography for demonstration of the venous drainage pattern and subsequent venous catheterization. Pneumomediastinography is recommended in suspected mediastinal parathyroid adenoma. Scanning with 75Se-selenomethionine is not in use because of its limited success.     

Technetium-99m sestamibi uptake in a maxillary brown tumor

Brown tumors have been reported to take up TI-201 when dual-tracer parathyroid scintigraphy using TI-201 and Tc-99m pertechnetate was performed. With the change to the more favorable Tc-99m sestamibi parathyroid scanning, similar phenomena of tracer uptake in brown tumors have been reported. The authors describe a 44-year-old man with a left maxillary swelling. Laboratory investigations revealed elevated parathyroid hormone levels. Computed tomography of the head showed a left maxillary expansile mass. Subsequently, a Tc-99m sestamibi scan was performed to rule out a parathyroid adenoma. Left inferior parathyroid retention of the tracer was seen, indicating a parathyroid adenoma. An incidental finding was the uptake of Tc-99m MIBI in the left maxillary brown tumor. This case suggests the utility and possible specificity of Tc-99m MIBI uptake in diagnosing brown tumors.     

Technetium-99m pertechnetate uptake in ectopic parathyroid adenoma

A 37-year-old male with a persistent increased parathyroid hormone level, after subtotal thyroidectomy and parathyroidectomy, was referred for scintigraphic localization of a possible ectopic parathyroid adenoma. Tc-99m pertechnetate and Tc-99m MIBI scintigraphy were performed on separate days. There was marked uptake of both tracers in the mediastinum, which at surgery was confirmed to be an extrathyroidal parathyroid adenoma. Hypervascularity was suggested as a possible explanation for rare cases of pertechnetate avid parathyroid adenomas. And Tc-99m MIBI scintigraphy proved to be a successful imaging procedure for ectopic parathyroid tissue.     

Calcified parathyroid glands detected by computed tomography

Computed tomographic demonstration of single calcified parathyroid glands in two patients corresponded to operative findings of a calcified carcinoma and a calcified adenoma. The CT demonstration of a calcified parathyroid gland should suggest carcinoma, and the operative approach should be planned to permit an en bloc resection.     

Dual-phase 99mTc-sestamibi imaging: its utility in parathyroid hyperplasia and use of immediate/delayed image ratios to improve diagnosis of hyperparathyroidism

OBJECTIVE: Dual-phase (99m)Tc-sestamibi (methoxyisobutylisonitrile [MIBI]) imaging is the technique of choice for hyperparathyroidism (HPT), especially for localizing parathyroid adenomas. Prior studies have shown its utility for detecting hyperplasia is equivocal, but we believe this is not true. We attempted to quantitate the region-of-interest counts per pixel between immediate images and delayed images (I/D ratio) and use this ratio to distinguish normal parathyroid versus hyperplasia versus adenoma. METHOD: Anterior pinhole and upper thorax images with a low-energy, high-resolution collimator at 20 min and 2 h after (99m)Tc-MIBI injection were obtained on 54 subjects. The results were analyzed retrospectively as hyperplasia, adenoma, or normal parathyroid by the persistence of activity in 2 or more foci, a solitary focus, or no activity on the delayed images. These interpretations were compared with pathology when available. I/D ratios were computed for all scans, and mean ratios were calculated for each type of pathology (normal parathyroid, hyperplasia, and adenoma). The resulting ratios were analyzed with a t test to determine significant differences between the ratios. RESULTS: Sensitivity and specificity were 96% and 88%, respectively, for parathyroid hyperplasia. Mean I/D ratios were 2.26 +/- 0.68, 2.80 +/- 0.95, and 3.10 +/- 0.77 for subjects with hyperplasia, adenoma, and normal parathyroid, respectively (hyperplasia vs. normal, P = 0.020; adenoma vs. normal, P = 0.381; hyperplasia vs. adenoma, P = 0.033). CONCLUSION: Dual-phase (99m)Tc-MIBI imaging is more sensitive and specific for parathyroid hyperplasia than reported previously, supporting its use to localize hyperplastic glands preoperatively and to help guide resection. A thyroid ratio between immediate and delayed images will aid in distinguishing hyperplasia from normal parathyroid in uncertain cases.     

Neoplasms of the parathyroid glands and brown tumours – A case study

A case of brown tumours concomitant with parathyroid adenoma is described. The patient described shoulder pain following minor trauma. Plain X-rays and MRI showed cystic bone lesions while blood analysis depicted high levels of calcium and parathyroid hormone (PTH). A ^99mTc-MDP wholebody bone scintigraphy showed extensive amplified uptake throughout the skeleton, supporting the diagnosis of brown tumours but not dismissing metastatic disease. A ^99mTc-Sestamibi Parathyroid Scan showed increased uptake in the right humerus, in the periphery of distal femora as well as tibiae and fibulae, ankles and multiple areas in both hands, supporting the diagnosis of brown tumours rather than metastases. The patient was subjected to a total parathyroidectomy and will receive follow-up to prevent further developments of the disease.     

Decreased Tc-99m sestamibi uptake in a sternal brown tumor indicating response to anti metabolic therapy for secondary hyperparathyroidism

Brown tumors are rare but serious complications of renal osteodystrophy, and can be treated by parathyroidectomy or by pharmacological treatment of hyperparathyroidism. In addition to parathyroid lesions such as adenoma, hyperplasia, and carcinoma, brown tumors have been detected effectively by using dual phase Tc-99m sestamibi and Tl-201 chloride. We describe an unusual case of brown tumor at the manibrium sterni which shows marked increased Tc-99m sestamibi uptake on the initial scan, with decreasing tracer activity on follow-up scan indicating a response to antimetabolic therapy.     

Large carotid sheath parathyroid adenoma localized by Tc-99m sestamibi

The use of Tc-99m sestamibi to localize parathyroid adenomas is well established. Its greatest value is in the detection of adenomas in presurgical candidates to localize one or more adenomas in the parathyroid glands or to identify ectopic parathyroid adenomas. The authors describe a patient who had long-standing hyperparathyroidism with a history of end-stage renal disease, hypertension, and peptic ulcers with gastrointestinal bleeding. The scan showed a large ectopic parathyroid adenoma in the left retrosternocleidomastoid region. At surgery, the adenoma was located between the jugular vein and the carotid artery, within the carotid sheath.