Intraoperative management of the thyroid gland in laryngeal cancer surgery

To determine if it is necessary to perform a hemithyroidectomy routinely with all total laryngectomies or if it should be reserved for selected cases.

A retrospective analysis of 215 cases who had been operated on due to laryngeal cancer in our clinic between 1985 and 1999.

In only 182 cases, hemithyroidectomy and isthmectomy were performed together with laryngeal surgery. Of these, 98% were male. Their ages ranged between 42 and 70 years. The tumour was located in the supraglottic region in 93 (51%) and in the glottic region in 24 (13%) cases. In 65 cases (36%), the tumour was transglottic. Twenty cases of transglottic tumours (31%) and 3 cases of glottic tumours (12.5%) were found to have subglottic extension.

Total laryngectomy with unilateral or bilateral neck dissection and hemithyroidectomy on the tumour side plus isthmectomy were performed on all patients. On the pathologic specimens, subglottic extension was measured anteriorly and posteriorly from the free edges of the vocal cords. The specimens were stained with hematoxylin and eosin and examined under a light microscope.

With glottic and transglottic carcinomas, the need for thyroidectomy may be based on the intraoperative assessment of the thyroid gland. In subglottic carcinomas, a hemithyroidectomy should routinely be performed. There may be no need to perform thyroidectomy in all total laryngectomy cases.

The thyroid gland was invaded by squamous cell carcinoma in only 2 cases (1%). Both of these cases were transglottic tumours staged as T3 and T4 and had a subglottic extension more than 1 cm.

We recommend routine hemithyroidectomy and isthmectomy during total laryngectomy only in cases with subglottic extensions more than 1 cm or thyroid cartilage invasion with tumour. In the other cases, assessment of extralaryngeal invasion and thyroid gland invasion by the tumour will determine whether thyroidectomy should be performed.