Answer for BIR CoW 09 July 2023
Ectopic lingual thyroid
Findings
Well defined mass with hyperdense and few cystic areas in the midline at the base of tongue with absence of thyroid gland at it’s orthotopic location in the neck. Impression – Ectopic lingual thyroid.
Discussion
Lingual thyroid is an abnormal mass of ectopic thyroid tissue seen in base of tongue caused due to embryological aberrancy in development of thyroid gland. Most of the ectopic tissue is seen in the tongue. Clinical symptoms usually seen in patients may range from dysphagia, dysphonia, snoring with a plumy voice, sore throat, occasional bleeding and upper airway obstruction though most of them remain asymptomatic until late adolescence. Rare cases of sleep apnea syndrome due to lingual thyroid have also been reported in the literature. Imaging features - At CT performed without contrast material administration, ectopic thyroid tissue demonstrates mildly increased attenuation (70 HU ± relative to adjacent muscle, a finding that is due to the intrinsic iodine content. Just as thyroid nodules appear as islands of low attenuation within the definitive thyroid gland, similar nodules within ectopic thyroid tissue can be a clue to the diagnosis. On T1-weighted MR images, ectopic thyroid tissue is typically isointense to mildly hyperintense compared with the musculature, and on T2-weighted MR images, ectopic thyroid tissue is mildly hyperintense, with variable enhancement after administration of a gadolinium-based contrast agent. A technetium or thyroid iodine scan confirms the diagnosis and will also identify the presence of any thyroid tissue elsewhere in the neck. The differential diagnosis for lingual thyroid should include vascular tumors, telangiectatic granuloma, teratomas, and benign or malignant processes in the posterior region of the tongue.
Management – Thyroid hormone supplements in case of hypothyroidism, surgical excision/laser ablation.
Findings
Well defined mass with hyperdense and few cystic areas in the midline at the base of tongue with absence of thyroid gland at it’s orthotopic location in the neck. Impression – Ectopic lingual thyroid.
Discussion
Lingual thyroid is an abnormal mass of ectopic thyroid tissue seen in base of tongue caused due to embryological aberrancy in development of thyroid gland. Most of the ectopic tissue is seen in the tongue. Clinical symptoms usually seen in patients may range from dysphagia, dysphonia, snoring with a plumy voice, sore throat, occasional bleeding and upper airway obstruction though most of them remain asymptomatic until late adolescence. Rare cases of sleep apnea syndrome due to lingual thyroid have also been reported in the literature. Imaging features - At CT performed without contrast material administration, ectopic thyroid tissue demonstrates mildly increased attenuation (70 HU ± relative to adjacent muscle, a finding that is due to the intrinsic iodine content. Just as thyroid nodules appear as islands of low attenuation within the definitive thyroid gland, similar nodules within ectopic thyroid tissue can be a clue to the diagnosis. On T1-weighted MR images, ectopic thyroid tissue is typically isointense to mildly hyperintense compared with the musculature, and on T2-weighted MR images, ectopic thyroid tissue is mildly hyperintense, with variable enhancement after administration of a gadolinium-based contrast agent. A technetium or thyroid iodine scan confirms the diagnosis and will also identify the presence of any thyroid tissue elsewhere in the neck. The differential diagnosis for lingual thyroid should include vascular tumors, telangiectatic granuloma, teratomas, and benign or malignant processes in the posterior region of the tongue.
Management – Thyroid hormone supplements in case of hypothyroidism, surgical excision/laser ablation.
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!