B-flow twinkling sign in preoperative evaluation of cervical lymph nodes in patients with papillary thyroid carcinoma

Radiological insights of ectopic thyroid in the porta hepatis: A case report and review of the literature

BACKGROUND

Ectopic thyroid is defined as a rare developmental anomaly where thyroid tissues are atypically found in locations other than its normal anatomical position: Anterolateral to the second, third, and fourth tracheal cartilages. An intemperate descent or a migration failure of the thyroid anlage results in sub-diaphragmatic thyroid ectopia, a sparse clinical entity.

CASE SUMMARY

This case portrays a 63-year-old female patient presenting with chronic abdominal discomfort at a local hospital whereby a computed tomography (CT) scan revealed a well-defined mass in the hepatic entrance. For further examination, the patient underwent a CT scan with contrast, magnetic resonance imaging (MRI), and CT-angiography (CTA) at our department. The CT scan showed a well-defined and high attenuated mass measuring 43 mm × 38 mm in the hepatic entrance with calcification. The CTA revealed an additional finding: Blood supply to the mass from the right hepatic artery. MRI of the upper abdomen demonstrated a mass with mixed signal intensity on T1 and T2 weighted images in the hepatic entrance. The patient underwent surgery with resection of the mass which was sent for histopathology. Ectopic thyroid at the level of porta hepatis with nodules was the definitive diagnosis since histopathological report revealed presence of thyroid tissue in the resected liver mass.

CONCLUSION

This case delivers a rare insight of pre-operative radiological imaging of an ectopic thyroid located in the liver. These findings can aid in narrowing down potential differential diagnosis when managing a patient with those subsequent findings.

Morphological, diagnostic and surgical features of ectopic thyroid gland: a review of literature

Ectopic thyroid tissue remains a rare developmental abnormality involving defective or aberrant embryogenesis of the thyroid gland during its passage from the floor of the primitive foregut to its usual final position in pre-tracheal region of the neck. Its specific prevalence accounts about 1 case per 100.000-300.000 persons and one in 4.000-8.000 patients with thyroid disease show this condition. The cause of this defect is not fully known. Despite genetic factors have been associated with thyroid gland morphogenesis and differentiation, just recently some mutation has been associated with human thyroid ectopy. Lingual region in the most common site of thyroid ectopy but ectopic thyroid tissue were found in other head and neck locations. Nevertheless, aberrant ectopic thyroid tissue has been found in other places distant from the neck region. Ectopic tissue is affected by different pathological changes that occur in the normal eutopic thyroid. Patients may present insidiously or as an emergency. Diagnostic management of thyroid ectopy is performed by radionuclide thyroid imaging, ultrasonography, CT scan, MRI, biopsy and thyroid function tests. Asymptomatic euthyroid patients with ectopic thyroid do not usually require therapy but are kept under observation. For those with symptoms, treatment depends on size of the gland, nature of symptoms, thyroid function status and histological findings. Surgical excision is often required as treatment for this condition.