Ectopic thyroid masquerading as submandibular tumour: a case report

A Rare Case of Coexistence Ectopic Lingual Thyroid and Thyroglossal Cyst with Tc 99 m Thyroid Scintigraphy

Lingual thyroid is a very rare anomaly and is usually incidentally found in patients that have hypothyroidism or mass in throat. This case however had another mass in the submandible with diagnosis of thyroglossal cyst. Thyroglossal duct cyst is the most common congenital neck mass. About 50% of cases present before the age of 10 and second group age present in young adulthood. We present a 27-year-old man who presented with sub-mental mass. The patient had also hypothyroidism. A CT scan was performed to confirm the diagnosis. The CT scan confirmed submental cyst and incidentally discovered lingual thyroid along with absence of thyroid tissue in its normal pretracheal position. The patient had symptoms of hypothyroidism and he was treated with levothyroxin. Our case report highlights a rare and unusual situation because of the coexistence of a thyroglossal cyst and a partially functional lingual thyroid.

Ectopic thyroid carcinoma. Case report

INTRODUCTION

Ectopic thyroid tissue can be found in many sites, including the tongue, thyroglossal duct, mediastinum, trachea, lung, aorta and abdomen. Ectopic thyroid tissue may also be involved in the same processes as normal, orthotopic thyroid gland. These processes include tumors, inflammation and hyperplasia. The appearance of such tissue in rare locations may lead to diagnostic and therapeutic dilemmas.

CASE REPORT

We report a rare case of ectopic thyroglossal thyroid carcinoma in a 63-year-old Caucasian male with a normal orthotopic thyroid gland.

CONCLUSION

Although 99% of thyroid cancers develop within the thyroid itself, in rare cases a carcinoma can arise in ectopic thyroid tissue located in the neck or in other areas of the body. Though rare, the possibility of an ectopic thyroid carcinoma must always be considered by the surgeon in cases of a pathological mass in the neck.

Lingual thyroid: diagnosis using a hybrid of single photon emission computed tomography and standard computed tomography

AIM

To present a rare case of lingual thyroid detected using a hybrid of single photon emission computed tomography and standard computed tomography in a young woman with hypothyroidism.

MATERIALS AND METHODS

A 29-year-old woman was screened for autoimmune thyroid disorders in early pregnancy, and found to have subclinical hypothyroidism. No thyroid tissue was found in the anterior neck upon ultrasonography, raising suspicions of an ectopic thyroid. The patient was treated with levothyroxine throughout the remainder of her pregnancy, and developed postpartum thyroiditis requiring an increase in levothyroxine dosage. Whole-body scintigraphy and zoomed static head and neck scintigraphy were performed. Abnormal 99mTc-pertechnetate uptake was observed in the oral region, whereas no uptake was found in the usual thyroid location. Hybrid imaging using single photon emission computed tomography and standard computed tomography was performed to improve three-dimensional representation of the area of increased activity.

RESULTS

The latter imaging modality detected ectopic thyroid tissue in the tongue.

CONCLUSION

Whole body 99mTc-pertechnetate scintigraphy and a hybrid of single photon emission computed tomography and standard computed tomography are effective imaging modalities for the investigation of ectopic thyroid tissue. The latter modality is particularly recommended, as it allows more precise spatial visualisation of increased isotope uptake activity in the head and neck.

Detection of ectopic thyroid remnants: a serious diagnostic dilemma. When molecular biology and immunohistochemistry can solve the problem

The presence of ectopic thyroid tissue is a frequent diagnostic feedback related to a possible histogenetic abnormality or a result of post-surgical seeding. The important challenge is the diagnostic definition of its nature, which could lead to a different therapeutic approach. We describe a case with all the possible implications and differential diagnoses supported by the application of immunohistochemistry and BRAF-V600E molecular detection. A 36-year-old girl with a left thyroid nodule underwent surgery with a diagnosis of angio-invasive tall cell variant of papillary carcinoma without lymph-node metastases. The patient history revealed a previous right lobectomy in another institution ten years before. The right neck dissection was histologically characterized by the presence of thymic residual and evidence of microfollicular microfoci (less than 1mm) of thyroid tissue. Thyroid tumor cells were positive for thyroglobulin, TTF-1, HBME-1 and Galectin-3, while the residual ectopic thyroid tissue showed positivity only for TTF-1 and thyroglobulin. The molecular tests on the thyroid nodule revealed the presence of BRAF-V600E mutation, but wild type BRAF in the ectopic tissue. The histo-morphological definition of these remnants plays the most important role, but the application of immunohistochemistry and molecular biology may help to reach a conclusive diagnosis.

Giant papillary carcinoma arising in the ectopic buccal thyroid tissue

BACKGROUND

Ectopic thyroid tissue very rarely occurs in the buccal region. Even more rarely encountered is the papillary carcinoma arising in the ectopic tissue.

METHODS AND RESULTS

We herein present a 78-year-old female patient admitted with a giant, buccal mass that developed within the previous 2 years. Physical examination revealed a vegetative mass on the left buccal region without any cervical lymphadenopathy. Magnetic resonance imaging scan showed an 8- × 6-cm solid mass with cystic components in the left buccal region and thoracic computed tomography scanning revealed pulmonary metastasis. A successful surgery including lower lip splitting was performed, and the mass was totally excised with its surrounding capsule. Histopathologic examination revealed follicular variant of papillary carcinoma of the ectopic thyroid tissue.

CONCLUSIONS

To our knowledge, our case is the first case of papillary carcinoma arising from ectopic thyroid tissue in the buccal region in the literature.

Ectopic lingual thyroid

Thyroid ectopy is characterized by the presence of thyroid tissue outside its normal position resulting from a defect of the thyroid diverticulum migration from the base of the tongue until its final pre-tracheal position. One case is presented in a 12-year-old girl patient who consults for a failure to thrive estimated at less than three standard deviations (SD). Bone age was estimated at 8 years late compared to chronological age. The hormonal assessment showed hypothyroidism with negative thyroid antibodies. Cervical ultrasound was revealed thyroid parenchyma pre-dominantly left in place while sweeping the area under chin showed a nodular formation of the base of the tongue. Thyroid scan with technetium 99 m showed a selective uptake of radiotracer in sublingual position. Cervical computed tomography revealed a posterior median sublingual mass spontaneously hyperdense and enhancing sharply after injection of contrast. Treatment with thyroxine allowed obtaining euthyroidism. This case asks us to be careful before aetiological diagnosis of hypothyroidism in children, because although this is rare, the presence of a thyroid parenchyma up to the cervical ultrasound does not eliminate the presence of ectopic tissue.