Lateral neck ectopic thyroid carcinoma: Rare location for ectopic malignancy

Lateral neck ectopic thyroid tissue remains a rare entity that can be affected by any lesion involving the gland. The origin of lateral neck ectopic thyroid carcinomas still debated between a metastatic disease secondary to thyroid primary tumor and primary malignancy on the ectopic tissue. Anyway, it should indicate an exploration of the gland. We report the case of a 36 years old female with one year history of hyperthyroidism who was admitted for multinodular grade II goiter with a firm mass in the left level II of the lateral neck. The thyroid scintigraphy demonstrated multiple functioning nodules corresponding to toxic multinodular goiter; in addition to two cold hypofunctional nodules. The cervical ultrasound showed a voluminous multinodular goiter classified as EU TIRADS 5. The surgical procedure exposed a multinodular mass, lateral to the internal jugular vein, with the appearance and structure of the thyroid gland and no connection to it. The thyroid gland was exposed next through a collar incision. Each mass was dissected and removed individually. The histopathology examination of the thyroid gland found papillary carcinoma extracapsular extension. The pathology results of the other mass reported multiple colloid nodules with cystic component, papillary in appearance, with the same cancer proliferation, compatible with ectopic thyroid tissue with papillary carcinoma. No lymph node tissue was found. The patient was sent for complementary RAItherapy. We report a rare case of lateral neck ectopic thyroid papillary carcinoma that supplements and supports the lacking literature data concerning the management of this rare entity.