Ectopic Intrathyroidal Parathyroid Adenoma Presenting With Osteoporotic Fractures in a Young Man: A Case Report

Primary hyperparathyroidism (PHPT) can be associated with osteoporosis (OP) and fractures. We present a case of a 49-year-old male referred to our osteoporosis outpatient clinic due to a right femur osteoporotic fracture. At the age of 38, a right plantar nodular lesion was excised, and its histology was compatible with a deep dermis nodule formed by mononuclear and giant osteoclast-like cells. He has reported osteoporotic fractures since age 39 and renal colic episodes since age 45. His father had lipomas and renal colic episodes, and his paternal grandmother had lipomas. The laboratory evaluation was compatible with PHPT. A cervical ultrasound showed a 10mm single solid nodule in the left thyroid lobe, strongly hypoechogenic, with microcalcifications. Its cytology showed parathyroid tissue without atypia. Parathyroid scintigraphy had no uptake. A dual-energy X-ray absorptiometry scan showed a femoral neck Z-score of -4.3. He started alendronate/cholecalciferol (70mg/5600IU) weekly. He was submitted to a left hemithyroidectomy. Its histology showed an intrathyroidal parathyroid adenoma. Ectopic parathyroid adenomas are rare, of which 0.7%-6% are intrathyroidal. The excised foot lesion could be a brown tumour. Furthermore, calcium metabolism evaluation at that time might have allowed a PHPT diagnosis and its morbidity prevention. Osteoporotic fractures in young men must alert to secondary OP.

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

OBJECTIVE

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

The Value of Preoperative and Intraoperative Ultrasound in the Localization of Intrathyroidal Parathyroid Adenomas

AIM

Intrathyroidal parathyroid adenoma (IPA) is rare and may easily be mistaken for thyroid nodule in ultrasonography. The aim of this study was to investigate the characteristic features of IPA and explore the value of preoperative and intraoperative ultrasound in the diagnosis and localization of IPA.

METHODS

13 of 216 patients who were found to have intrathyroidal parathyroid lesions underwent parathyroidectomy in our hospital because of PHPT. According to the relationship between parathyroid adenoma and thyroid gland, parathyroid adenoma was divided into extra-thyroid type or intra-thyroid type (partial or complete) and the results were compared with surgical and histopathological reports as gold standard. The sonographic features of intrathyroidal parathyroid lesions were analyzed retrospectively.

RESULTS

A total of 12 intrathyroidal lesions showed profoundly hypoechoic solid nodules with well-defined border, abundant blood flow and polar feeding vessels originating from the superior or inferior thyroid artery (92.3%, 12/13). These nodules were finally confirmed as IPA (or IPAC) after surgery. Polar feeding vessel was not detected in one case of parathyroid hyperplasia confirmed by pathology (7.7%, 1/13). 12 cases were diagnosed and localized on ultrasonography before operation and 10 cases were localized on Tc-99m MIBI SPECT/CT.

CONCLUSIONS

The color Doppler ultrasound findings of IPA were confirmed as profoundly hypoechoic nodules with clear boundary and abundant internal blood flow. The presence of polar feeding vessels which originate from thyroid artery were identified as characteristic features of US for IPA. Preoperative and intraoperative ultrasound could be helpful in the localization and treatment of intrathyroidal parathyroid diseases.

Intrathyroidal parathyroid adenoma: Diagnostic pitfalls on fine-needle aspiration: Two case reports and literature review

Parathyroid adenomas may occur within the thyroid, clinically simulating thyroid nodules. Fine-needle aspiration (FNA) of these presumably "thyroid nodules" can lead to misinterpretation of cytomorphological findings because of similarities in cytological features of parathyroid and thyroid lesions. Here, we reported two cases of intrathyroidal parathyroid adenomas. One of them was misinterpreted as thyroid lesions. The other was composed exclusively of oncocytic cells and had a correct cytological diagnosis. In this study, both cases showed a new cytological feature which has not been reported in the literature: many capillaries protruding outside the three-dimensional fragments without epithelial cells around. Diagn. Cytopathol. 2016;44:921-925. © 2016 Wiley Periodicals, Inc.

Life-threatening intrathyroidal parathyroid adenoma

Acute primary hyperparathyroidism and parathyroid crisis are characterized by life-threatening hypercalcemia, a rare disorder. A 69-year-old female patient presented at our hospital's neurology clinic with weakness, nausea, vomiting, depression, and hypercalcemia. Treatment of hypercalcemia resulted in no improvement in neurological symptoms, indicating resistance to treatment. Thyroid ultrasonography and parathyroid scintigraphy revealed hypoechoic nodules in the right lobe, pieces of nodules in the left lobe, and high serum calcium and parathyroid hormone levels. After provision of intensive medical treatment including hydration, diuresis, and bisphosphonate infusion resulted in only minimal decrease in the calcium level, urgent surgical treatment was performed. Frozen biopsy of the right intrathyroidal giant parathyroid adenoma in the right lobe confirmed initial diagnosis of primary hyperparathyroidism. Based on the biopsy findings, right parathyroidectomy and right total and left subtotal thyroidectomy were performed. Histopathologic examination revealed a parathyroid adenoma localized inside large thyroid nodules. Review of the findings resulted in diagnosis of intrathyroidal parathyroid adenoma. Symptoms of hypercalcemia improved rapidly during the postoperative period.

Giant intrathyroidal parathyroid adenoma

Primary hyperparathyroidism (PHPT) is not an uncommon endocrine disorder. However, acute primary hyperparathyroidism, or parathyroid crisis (PC), is a rare clinical entity characterized by life-threatening hypercalcemia of a sudden onset in patients with PHPT. We describe a patient with PC who presented with acute worsening of depressive symptoms, nausea and vomiting, and required emergency surgery. Serum calcium, alkaline phosphatase, and parathyroid hormone were elevated and serum phosphorus was low. An emergency hemithyroidectomy was performed because of none medical control of hypercalcemia. A giant intrathyroidal parathyroid adenoma was diagnosed. PHTP can be a life-threatening situation for patients, requiring immediate surgical treatment. A giant intrathyroidal parathyroid adenoma is an uncommon cause of PC.