Intrathyroidal parathyroid adenoma mimicking thyroid cancer

Management of Type III Intrathyroidal Parathyroid Adenomas By Enucleation: Case Report and Literature Review

Parathyroid adenoma is a common endocrine disorder, but its intrathyroid presentation is relatively rare. The traditional approach, such as thyroid blind lobectomy, is the most frequent modality of treatment due to the possible unclear localization of the adenoma in the preoperative workup. This increases the risk of unnecessary probability of hypothyroidism.  We report a case of a 48-year-old male patient who was referred to the endocrinology outpatient clinic due to elevated calcium (Ca) and elevated parathyroid hormone (PTH) levels, indicating primary hyperparathyroidism (PHPT). Thyroid ultrasound (US) confirmed the presence of thyroid lobe nodule and the fine needle aspiration cytology (FNAC) revealed the presence of parathyroid cells. A thyroid scan with the single photon emission computed tomography (SPECT)/CT revealed a possible left inferior parathyroid adenoma. The patient underwent surgical excision of the left parathyroid adenoma by cervicotomy and thyroid lobe preservation with prompt normal PTH level recovery without complications. One year follow-up revealed no complications, and the patient's serum thyroid function, PTH, and Ca levels remained within the normal range. The management of type III intrathyroidal parathyroid adenomas (iT-PAs) by enucleation offers a viable alternative for selected PHPT patients. Advanced diagnostic imaging helps but is often not able to confirm exactly their location. Individualized surgical approaches contribute to successful outcomes while preserving thyroid tissue. The establishment of standardized guidelines is essential to optimize the management of iT-PAs and enhance patient care. We present a case of a type III iT-PA by enucleation preserving the thyroid tissues along with the analysis of the few cases previously reported.

Incidental synchronous intrathyroidal parathyroid carcinomas and papillary thyroid microcarcinoma with compressive neck mass and primary hyperparathyroidism: case report and literature review

BACKGROUND

Parathyroid carcinoma (PC) is a rare malignancy, often diagnosed incidentally through postoperative pathological examination. The occurrence of nodular goiter, intrathyroidal parathyroid carcinoma, contralateral parathyroid adenoma (PA), and papillary thyroid microcarcinoma (PTMC) is extremely uncommon, which prompted us to report our case experience.

CASE PRESENTATION

We describe a 67-year-old male who presented with a cervical mass causing tracheal compression, which prompted him to seek medical advice. Based on preoperative auxiliary examination results from color Doppler ultrasound, SPECT parathyroid imaging, and blood tests, he was initially diagnosed with a suspected parathyroid adenoma and nodular goiter. Excision of the right lobe and isthmus of the thyroid, and left superior parathyroid gland was conducted, which were sent to intraoperative frozen pathological examination. During intraoperative observation, adhesion around the right thyroid lobe was discovered. Consequently, right central area lymph node dissection was performed due to suspicion of an aggressive malignant tumor. Histology and immunohistochemistry analysis revealed incidental intrathyroidal parathyroid carcinoma, contralateral parathyroid adenoma, classical papillary thyroid microcarcinoma, and nodular goiter.

CONCLUSION

Parathyroid carcinoma should be highly suspected when extremely high levels of PTH and severe hypercalcemia are present, which cannot be simply explained by a preoperatively localized parathyroid adenoma, especially when suspicious malignant adhesion is found during intraoperative exploration. In cases where multifocal thyroid nodules are associated with increased uptake of 99Tc-sestamibi, the possibility of coexisting carcinomas should be considered, not only for thyroid malignancy but also for the potential presence of intrathyroidal parathyroid carcinoma.

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.

Common Key Genes in Differentiating Parathyroid Adenoma From Thyroid Adenoma

Recent studies have demonstrated the close relationship between parathyroid adenoma (PA) and thyroid follicular adenoma (FTA). However, the underlying pathogenesis remains unknown. This study focused on exploring common pathogenic genes, as well as the pathogenesis of these two diseases, through bioinformatics methods. This work obtained PA and FTA datasets from the Integrated Gene Expression Database to identify the common differentially expressed genes (DEGs) of two diseases. The functions of the genes were investigated by GO and KEGG enrichment. The program CytoHubba was used to select the hub genes, while receiver operating characteristic curves were plotted to evaluate the predictive significance of the hub genes. The DGIbd database was used to identify gene-targeted drugs. This work detected a total of 77 DEGs. Enrichment analysis demonstrated that DEGs had activities of 3',5'-cyclic AMP, and nucleotide phosphodiesterases and were associated with cell proliferation. NOS1, VWF, TGFBR2, CAV1, and MAPK1 were identified as hub genes after verification. The area under the curve of PA and FTA was>0.7, and the hub genes participated in the Relaxin Signaling Pathway, focal adhesion, and other pathways. The construction of the mRNA-miRNA interaction network yielded 11 important miRNAs, while gene-targeting drug prediction identified four targeted drugs with possible effects. This bioinformatics study demonstrated that cell proliferation and tumor suppression and the hub genes co-occurring in PA and FTA, have important effects on the occurrence and progression of two diseases, which make them potential diagnostic biomarkers and therapeutic targets.

Primary hyperparathyroidism-related giant parathyroid adenoma (Review)

Primary hyperparathyroidism (PHPT), an endocrine condition caused by a parathyroid adenoma (PTA) in 80-85% of the cases, has shifted in the modern era to a mildly symptomatic phenotype due to the prompt recognition of hypercalcemia and to a minimally invasive surgical approach which has a curative potential. Clinical complications of PHTH are either related to high calcium or parathyroid hormone [also parathormone (PTH)] or both, while the originating tumor typically is small, without local mass effects. A distinct entity is represented by giant PTA (GPTA) which is considered at a weight of more than 3 (3.5) grams. The present article is a review of the literature involving practical points of non-syndromic PHPT-related GPTA. Most authors agree that pre-operatory calcium and PTH are higher in GPTA vs. non-GPTA. However, the clinical presentation of PHPT may be less severe, probably due to local mass effects that bring the patient to an early medical evaluation. Age distribution, sex ratio, rate of successful pre-operatory location do not differ from non-giant PTA. Hypovitaminosis D is more frequent in PTA of higher dimensions. Post-operative hypocalcemia, but not recurrent/persistent PHPT, is expected, even hungry bone disease. A higher rate of atypia is described although the tumor is mostly benign. Unusual presentations such as cystic transformation, initial diagnosis during pregnancy or auto-infarction have been reported. The ectopic localization of PTA presented in almost 15% of all cases may also be found in GPTA. What are the exact cutoffs for defining GPTA is still an open issue.