Management of paratracheal adenoid cystic carcinoma.

A 36-year-old woman presented with an incidental finding of a fight paratracheal/paraesophageal mass. The growth had been found on magnetic resonance imaging (MRI) of the neck during an evaluation of a posterior cervical lipoma. The patient denied otalgia, weight loss, odynophagia, dysphagia, hemoptysis, and respiratory distress. The MRI of the neck had revealed the presence of a heterogenously enhancing 3.7 x 3.7 x 2.6-cm mass inferior to the right inferior pole of the thyroid and wrapping posterior to the trachea (figure 1). Findings on fine-needle aspiration biopsy were consistent with an epithelial neoplasm, and they ruled out the thyroid as the origin of the mass.

[FIGURE 1 OMITTED]

In an attempt to make a definitive diagnosis, we performed direct laryngoscopy, bronchoscopy, and esophagoscopy; all findings were normal. We then obtained an open biopsy of the mass, and the histologic findings were consistent with adenoid cystic carcinoma.

In view of the location of the tumor, the patient opted for tumor debulking followed by radiation rather than en bloc resection. During surgery, the fight recurrent laryngeal nerve was identified within the tumor mass, and it was separated from the tumor in order to preserve it. The carotid artery, thyroid, trachea, and esophagus were all intimately associated with the mass, and all were spared (figure 2, A and B). However, the tumor did infiltrate the submucosa of the trachea; resection of this portion of the tumor resulted in a 2-cm tracheal defect that required primary repair (figure 2, C). The patient recuperated uneventfully, and she subsequently underwent neutron radiotherapy.

[FIGURE 2 OMITTED]

Adenoid cystic carcinoma is a malignancy of salivary gland origin. It can develop in both the major and minor salivary glands. Cases of laryngotracheal adenoid cystic carcinoma have been reported in the literature, but they all involved endolaryngeal and/or endotracheal masses. Only a few cases of tracheal adenoid cystic carcinoma presenting as a thyroid mass as a result of tumor invasion through the tracheal wall into the neck have been previously reported. (1-5) The case of our patient is similar to these earlier cases with regard to the cervical component of the mass, but no endotracheal component of the tumor was found on endoscopy in our case.

En bloc resection of our patient's tumor would have required tracheal resection and esophagectomy, and it would have resulted in significant morbidity and poor quality of life. A study of unresectable adenoid cystic carcinoma by Douglas et al found that tumor debulking followed by neutron radiotherapy yields fairly good results. (6) They studied 151 patients who had gross residual disease that had been treated with neutron radiotherapy. The 5-year actuarial cause-specific survival rate was 87% for patients who had undergone surgical debulking prior to radiotherapy, compared with 64% for those who had undergone only biopsy prior to radiotherapy. The 5-year actuarial locoregional control rates were 71 and 43%, respectively. Based on these findings and quality-of-life issues, we believe that tumor debulking with postoperative neutron radiotherapy is the treatment of choice for this type of tumor.

References

(1.) Idowu MO, Reiter ER, Powers CN. Adenoid cystic carcinoma: A pitfall in aspiration cytology of the thyroid. Am J Clin Pathol 2004;121:551-6.

(2.) Natarajan S, Greaves TS, RazaAS, Cobb CJ. Fine-needle aspiration of an adenoid cystic carcinoma of the larynx mimicking a thyroid mass. Diagn Cytopathol 2004;30:115-18.

(3.) Na DG, Han MH, Kim KH, et al. Primary adenoid cystic carcinoma of the cervical trachea mimicking thyroid tumor: CT evaluation. J Comput Assist Tomogr 1995;19:559-63.

(4.) Reiter ER, Idowu MO, Powers CN. Unusual paratracheal masses presenting with vocal fold paralysis. Ear Nose Throat J 2006;85: 112-15.

(5.) Zirkin HJ, Tovi F. Tracheal carcinoma presenting as a thyroid tumor. J Surg Oncol 1984;26:268-71.

(6.) Douglas JG, Laramore GE, Austin-Seymour M, et al. Treatment of locally advanced adenoid cystic carcinoma of the head and neck with neutron radiotherapy. Int J Radiat Oncol Biol Phys 2000;46: 551-7.

Sofia Avitia, MD; Jason S. Hamilton, MD; Ryan F. Osborne, MD, FACS 

From the Osborne Head and Neck Institute, Los Angeles.