Invasion of the recurrent laryngeal nerve by adenoid cystic carcinoma. An unusual cause of true vocal fold paralysis

Abstract

True vocal fold paralysis and goitre are both common problems encountered in ENT practice. Their co-existence, however, should arouse suspicion of the presence of malignant thyroid disease. A rare case of true vocal fold paralysis caused by a clinically occult subglottic adenoid cystic carcinoma, in a 72-year-old, is described. The existence of multinodular goitre in this patient was co-incidental and confounded the diagnostic process.

Unique presentation of adenoid cystic carcinoma in postcricoid region: a case report and review of the literature

“…Previous case reports of AdCC in the larynx are listed in the table [2,4,6,9,[17][18][19][20][21][22]. Of these cases, none is described as arising in the exact location as our patient's tumor.…”

A study on internal laryngeal nerve-its variation in the course, branching, anastamosis and relation to inferior thyroid artery

“…This does not agree with the work of weeks and Hinton who stated that only 5% of the nerves do not divide. 13 The level of division according to Morrison is up to 0.5cm below the point of entry; here nearest level of division is 1cm. 14 The number of branches also showed a variation in number.…”

Difficult Problems in Thyroid Surgery

“…Nonmalignant disease such as Reidel's thyroiditis, Hashimoto's thyroiditis, and Graves' disease can compress the recurrent laryngeal nerve and cause paralysis. 162,163 Invasion of the recurrent laryngeal nerve by papillary, follicular, and medullary thyroid carcinoma is frequently associated with invasion of other adjacent structures, including the larynx, trachea, and esophagus. 139 Medullary thyroid cancer also is associated with invasion of the vagus nerves.…”

“…162 When recurrent laryngeal nerve paralysis is present, it is prudent to image the neck with CT scanning or MRI to estimate the size and extent of the thyroid enlargement. 163 The evaluation is similar to that for assessment of respiratory tract invasion. 124 Direct or indirect laryngoscopy is useful for assessment of the patient's symptoms and for assistance with intraoperative decisions to sacrifice a unilaterally involved recurrent laryngeal nerve.…”