Rare concurrence of ectopic intrathyroidal parathyroid gland and papillary thyroid carcinoma within a thyroid lobe

Abstract

Rationale: The inferior parathyroid glands derive from the third branchial pouch and seldom ectopically migrate to thyroid grand, mediastinum, thymus. Ectopic intrathyroidal parathyroid grand (ETPG) is rare and it cannot be consistently detected by any imaging examinations. The unusual ETPG is easily resected during thyroidectomy, which might cause postoperative hypoparathyroidism. Auto-transplantation of even a parathyroid gland can restore parathyroid function to some extent. Until now, there are not any guidelines on the management of ETPG. Patient concerns: Without any symptoms, a 27-year-old female patient was admitted to our hospital for a thyroid nodule. Thyroid ultrasonography demonstrated a hypoechoic nodule, measuring 0.6 cm × 0.6 cm × 0.7 cm, with multiple punctate micro-calcifications within the right thyroid lobe. Thyroid function tests were normal. The invasive fine needle aspiration cytology for the thyroid nodule was rejected by patient. Diagnoses: The patient was firstly diagnosed as right thyroid hypoechoic nodule, which was pathologically proved to be papillary thyroid carcinoma (PTC) finally. Interventions: The patient underwent right thyroidectomy, central compartment neck dissection, parathyroid exploration, and auto-transplantation of the normal ETPG. Outcomes: The right thyroid hypoechoic nodule was diagnosed as PTC by pathological examination. The inferior parathyroid gland could not found in normal locations. On the cut surface of excised thyroid lobe, a yellow and soft nodule was discovered and it was pathologically diagnosed as a normal parathyroid grand. In the end, auto-transplantation of the normal ETPG was conducted. Postoperative follow-ups found both serum calcium and parathyroid hormone tests were normal. Lessons: ETPG in a patient with PTC is easily overlooked and unexpectedly excised for its rarity. ETPG brings about a failed parathyroid exploration. However, within the thyroid parenchyma, it might be occasionally discovered by cutting a thyroid lobe into slices. Auto-transplantation of normal ETPG is necessary.

Co-occurrence of bilateral intrathyroidal parathyroid gland and papillary thyroid carcinoma; a case report

“…This might be because normal ITP is asymptomatic and US is insensitive in detecting them, while abnormal ITP lesions are associated with hyperparathyroidism and can more easily be distinguished through imaging techniques and FNA [17] , [18] . Both Chen et al and Velimezis et al in their studies reported that ectopic ITP was not detected through US and was accidently found during postoperative histological examination of the other present thyroid lesion, reportedly PTC [15] , [16] . The case in the current study was diagnosed for PTC through FNA without any detection of an ITP on US, and patient laboratory results were in normal limits.…”

“…Previous reports of ITP have demonstrated that ITP is usually asymptomatic, and any symptom or clinical findings are linked to associated thyroidal lesion that might be present [15] , [16] . Chen and colleagues reported a 27-year-old asymptomatic female case of ectopic ITP and PTC with normal family and medical history [15] .…”

“…Previous reports of ITP have demonstrated that ITP is usually asymptomatic, and any symptom or clinical findings are linked to associated thyroidal lesion that might be present [15] , [16] . Chen and colleagues reported a 27-year-old asymptomatic female case of ectopic ITP and PTC with normal family and medical history [15] . Velimezis et al also reported a 26-year-old asymptomatic case which demonstrated the concurrence of ectopic ITP, PTC, and ectopic intrathyroidal thymus with a past medical history of genitourinary system disorders [16] .…”

“…The presence of ITP when co-occurring with other thyroidal lesions present a challenge to physicians as due to their rarity, insensitivity to imaging techniques, and their invisibility during thyroidectomy as the result of the lack of a distinguishable cleavage plane with the thyroid parenchyma, surgeons are unaware of their presence inside the thyroid, even if they are found, they simply cannot be easily freed from the thyroidal tissue [4] , [15] . Chen and associates in their study suggested that surgeons should carefully examine the thyroidal tissue to discover any possible normal ITP, so that they can later perform auto-transplantation of the ITP in order to prevent hypocalcemia due to postoperative hyperthyroidism [15] .…”

An intrathyroidal nodule consisting of papillary thyroid cancer and ectopic hyperechoic parathyroid adenoma: a case report

“…Apart from thyroid nodules, non-thyroidal tissues such as parathyroid, thymus, salivary gland, uncommon cysts, lymph node and metastasis can be completely embedded in the thyroid, and most of these ectopic nonthyroidal tissues appear as predominantly hypoechoic on US [1,8,9]. In the differential diagnosis of thyroid nodules, this wide spectrum of the lesions should be always considered.…”