Ectopic submandibular thyroid tissue with a coexisting normally located multinodular goitre: case report and review of the literature

Abstract

The simultaneous finding of submandibular ectopic thyroid tissue and functional orthotopic thyroid gland is an extremely rare event. The present report describes the case of a woman presenting with a left submandibular mass, distant from a palpable multinodular goitre. Ultrasonography showed an ovoidal solid mass adjacent to the lower margin of the left submandibular gland. Cytological specimens showed colloid material and thyroid follicular cells with no malignant features. A preoperative CT scan demonstrated a very thin connection between the thyroid and the submandibular mass. The patient underwent total thyroidectomy and excision of the submandibular mass. The histopathological diagnosis of the thyroid tissue was multinodular goitre, and the submandibular mass was ectopic thyroid tissue showing a hyperplastic pattern. The main differential diagnosis of the submandibular mass was a metastasis from a well differentiated cancer. This case illustrates that an ectopic thyroid off the midline may not necessarily be a metastasis from a thyroid cancer.

Submandibular Lateral Ectopic Thyroid Tissue: Ultrasonography, Computed Tomography, and Scintigraphic Findings

“…Ectopic thyroid tissue in the submandibular space with the thyroid gland in its normal location is an extremely rare phenomenon [ 4 ]. There are few available case reports in the literature on this issue [ 2 – 9 ].…”

Submandibular ectopic thyroid with normally located thyroid gland

“…Four of seven reported cases who had submandibular ectopic thyroid and a functional orthotopic thyroid revealed nodular goiter. [7][8][9][10] Furthermore, two of these four cases had a history of previous thyroidectomy for nodular goiter. It may be that implantation of thyroid tissue during previous surgery of an orthotopic thyroid gland is the possible cause of these cases.…”

“…Thyroid tissue with goitrous change Surgical excision Piantanida et al [9] F Thyroid follicular cells with no malignant features Surgical excision Amoodi et al [10] F Thyroid goiter Surgical excision Table 1. Previously reported cases of simultaneous finding of submandibular ectopic thyroid and a functional normally located thyroid gland invagination in the foramen cecum from the base of the tongue to the front of the anterior tracheal wall, where it reaches its final position in the seventh week.…”

“…To our knowledge, only seven cases of simultaneous submandibular ectopic thyroid tissue and a functional orthotopic thyroid gland have been reported in the literature (Table 1). [4][5][6][7][8][9][10] In this article, we report a case of a woman presenting with submandibular ectopic thyroid tissue and an orthotopic thyroid gland.…”

Colloid goiter in ectopic thyroid tissue presenting as submandibular swelling with a coexisting functional orthotopic thyroid gland in a pregnant female

“…The simultaneous finding of the submandibular ectopic thyroid tissue and a functional orthotopic thyroid gland is an extremely rare event. [3] As in many cases, the ectopic thyroid gland is the only functioning thyroid. The incidence of malignancy arising in ETT is approximately 1%.…”