Occult Thyroid Carcinoma without Malignant Thyroid Gland Findings during Preoperative Examination: Report of Three Cases

Abstract

Occult thyroid carcinoma preceded by clinical manifestations and findings from extrathyroidal tumors is rare. The lack of malignant findings in the thyroid during the preoperative examination makes diagnosis difficult. We encountered a 71-year-old man with a primary ectopic thyroid carcinoma causing superior vena cava syndrome. Although no malignant findings were found in the thyroid gland, biopsy of bone metastases led to the diagnosis of thyroid cancer. HE staining of bone metastases revealed nuclear features of papillary carcinoma, and immunostaining was positive for thyroglobulin and PAX-8. The second case involved an 84-year-old man with a mediastinal tumor and suspected thyroid cancer because of high thyroglobulin levels in blood. The pathological tumor finding was papillary thyroid cancer. The last case was that of a 56-year-old woman lacking preoperative thyroid examination malignant findings, but with cervical lymph node metastasis. The thyroglobulin level of the lymph node puncture fluid was useful for preoperative diagnosis. We performed total thyroidectomy plus bilateral modified neck dissection. Pathology revealed a 1 mm papillary carcinoma in the left lobe. All of these cases were difficult to diagnose. However, we combined the results of various tests such as radiographic imaging, blood tests, and immunohistological tests to diagnose our patients.

Personalized Management of Malignant and Non-Malignant Ectopic Mediastinal Thyroid: A Proposed 10-Item Algorithm Approach

“…Cancers 2024, 16, x FOR PEER REVIEW 37 of 55 and thymectomy in a patient with a prior history of thyroidectomy for cervical thyroid cancer [123]; left hemi-thyroidectomy and isthmectomy plus median sternotomy [129]; partial sternotomy and total thyroidectomy associated with a selective parathyroidectomy via mediastinal and cervical exploration [115].…”

“…The longest period of follow-up sinc reported data is up to one to two years [ showed that EMTs remained stable for a that were not removed upon cytological c 1/7 patient had a post-operatory complication: chyle leak & phrenic nerve injury (conservative approach) Gao 2023 [7] Cancers 2024, 16, x FOR PEER REVIEW 37 of 55 and thymectomy in a patient with a prior history of thyroidectomy for cervical thyroid cancer [123]; left hemi-thyroidectomy and isthmectomy plus median sternotomy [129]; partial sternotomy and total thyroidectomy associated with a selective parathyroidectomy via mediastinal and cervical exploration [115].…”

“…The associated (iatrogenic) hypothyroidism via thyroxine replacement is corrected in benign thyroid disease, too. Of note, levothyroxine-based TSH suppression therapy instead of surgery for benign EMTs in euthyroid patients [102] was not successful, and they are no longer encouraged according to the modern endocrine perspective (as similarly seen in 1/4 patient had a synchronous thymus lipoma Cancers 2024, 16, x FOR PEER REVIEW 37 of 55 and thymectomy in a patient with a prior history of thyroidectomy for cervical thyroid cancer [123]; left hemi-thyroidectomy and isthmectomy plus median sternotomy [129]; partial sternotomy and total thyroidectomy associated with a selective parathyroidectomy via mediastinal and cervical exploration [115].…”

“…Follow-up of the thyroid function af for (transitory) early post-operatory h The associated (iatrogenic) hypothyr in benign thyroid disease, too. Of note, levothyroxine-based TSH s nign EMTs in euthyroid patients [10 encouraged according to the moder thyroid nodules of the eutopic gland median follow-up: 39.5 months Vuorisalo 2023 [49] Cancers 2024, 16, x FOR PEER REVIEW 37 of 55 and thymectomy in a patient with a prior history of thyroidectomy for cervical thyroid cancer [123]; left hemi-thyroidectomy and isthmectomy plus median sternotomy [129]; partial sternotomy and total thyroidectomy associated with a selective parathyroidectomy via mediastinal and cervical exploration [115].…”

Ectopic thyroid tissue in the lateral lymph nodes: A rare case and literature review

“…Cytologic evaluation has a higher speci city but a lower sensitivity, and the combination of FNA-Tg and FNAC examination is widely recommended (43-46, 48, 51). In most cases, noticeably elevated FNA-Tg, even without cytologic evidence, can strongly indicate the existence of lymphatic metastasis (52), and therefore, further thyroidectomy and neck dissection are usually performed. However, false-positive results may lead to misdiagnosis and unnecessary surgery, which can be explained by three main reasons.…”