LCSE was defined as a tumor that originated in the supraglottis or glottis and extended to the subglottis more than 10 mm anteriorly or 5 mm posteriorly; pN0 was defined as representing resected cervical lymph nodes that were histologically free of metastatic neoplasm.
Included in this cohort was 1 patient with a history of definitive radiotherapy for stage I laryngeal glottic cancer who had undergone salvage laryngectomy with bilateral lymph node dissection for LCSE.
The level VI (prelaryngeal) node was removed when LCSE was detected before or during surgery, which occurred in 8 patients.
Survival according to the Kaplan-Meier analysis was estimated from the time of LCSE diagnosis until death or the date of the last follow-up.
The recurrence rate was 29% (2/7) when the LCSE was 10 mm or smaller and 27% (3/11) when it was larger than 10 mm.
LCSE can involve the other parts of the larynx, which had occurred in most of our patients, by direct mucosal and submucosal extension, lymphatic spread, or direct invasion of adjacent structures.
LCSE is a known predisposing factor for the development of stomal recurrence.
Analysis of our patients who did not receive postoperative radiotherapy revealed that they had a greater than 20% risk of neoplastic recurrence in the neck when the central compartment lymph nodes were not removed (because the LCSE was not appreciated prior to definitive surgery) and thyroid gland lobectomy was not performed with TLND.
Fewer than 40 cases of LCSE following TLND have been reported in the literature.
When LCSE is confirmed, the current management algorithm at our university-affiliated institutions includes a determination of the extent of subglottic disease and then, as a minimum, the removal of the entire larynx, the ipsilateral thyroid lobe and isthmus, the paratracheal nodes bilaterally, and the level VI node.