Intra-parenchymal thyroid epidermal cyst presenting with a left recurrent laryngeal nerve palsy

Abstract

We present a rare case of an intra-parenchymal thyroid epidermal cyst presenting with a left recurrent laryngeal nerve palsy. There was a complete recovery of the nerve function following surgical excision of the lesion. Theories of aetio-pathogenesis of the cyst and underlying mechanisms responsible for the nerve paralysis are explored.

Fine‐needle aspiration cytology of epidermoid cyst of the thyroid: Report of a case and review of seven cases

“…Structures derived from congenital rests in the thyroid such as thymic rest, thyroglossal duct remnant, and brachial cleft cyst may contain squamous epithelium. [3][4][5] One case was cytologically reported as inconclusive. However, it is completely intrathyroidal.…”

“…[1][2][3][4][5] Here, the cytologic and histologic findings of a new case are described, and the differential diagnosis and histogenesis are discussed. [1][2][3][4][5] Here, the cytologic and histologic findings of a new case are described, and the differential diagnosis and histogenesis are discussed.…”

Recurrent laryngeal nerve palsy in benign thyroid disease: can surgery make a difference?

“…The left RLN has a longer course than the right and hence is considered to be more prone to injury [5,6]; however, in our experience there was an even distribution between the right and left.…”

“…The nerve may be stretched as a consequence of thyroid lobe enlargement, but it could also be compressed with both mechanisms resulting in ischaemia and subsequent paralysis, either incomplete or complete. Other suggested mechanisms of injury include a pre-tracheal compartment syndrome or inXammation, although in the cases reported no clinical or histopathological evidence of these mechanisms was clearly demonstrated [5,6,8].…”

“…The association of pre-operative RLN palsy and thyroid disease is suggestive of locally advanced malignant thyroid disease by invasion of the nerve. However, the risk of benign thyroid disease causing paralysis to the nerve is extremely rare and has only been reported in isolated case reports [6,7] and small case series [5,8].…”