Clinicodemographic and Computed Tomography Scan Findings Associated with Thyroid Gland Invasion among Patients with Laryngeal Squamous Cell Carcinoma.

OBJECTIVE

We aim to determine the association between preoperative CT scan findings of thyroid cartilage invasion, cricoid cartilage invasion, and paraglottic space involvement with tumor extension to the thyroid gland on final histopathology among patients with laryngeal squamous cell carcinoma (SCC) in a tertiary hospital in the Philippines.

METHODS

Patients with histopathologically-confirmed laryngeal SCC who underwent total laryngectomy with thyroidectomy while admitted at the public ward of the Department of Otorhinolaryngology, Philippine General Hospital, from January 2013 to December 2019 were included. CT scans were reviewed by 2 blinded independent radiologists. CT scan data including subsite/s involved, thyroid cartilage/cricoid cartilage erosion, paraglottic space involvement, thyroid gland involvement, and thyroid gland involvement on final histopathology were gathered. Clinicopathologic data such as age, T Stage, early tracheostomy, and time between CT scan and surgery were also collected and analyzed. Fisher's exact test was computed for both clinicopathologic and CT scan data with a significant value having p<0.05. Cramer's V and phi coefficient were computed for nondichotomous and dichotomous variables, respectively. Odds ratio was also computed for dichotomous variables with p<0.05 on Fisher's exact test.

RESULTS

Fifty-nine (59) men and 4 women were included, aged 43 to 81 years old. Most patients were classified as T3 (n=18) and T4 (n=41) (total=93.7%), with most having transglottic primary tumors (n=29, 46%), and only 8 (12.7%) patients having subglottic tumor involvement on final histopathology. Thyroid cartilage erosion or invasion were noted in 63.4% (n=40) of patients' CT scans and 58.7% (n=37) of patients' final histopathology reports. Cricoid cartilage and paraglottic space involvement were often not reported on final histopathology results. Thyroid gland involvement was only noted in the final histopathology reports of 5 patients (7.9%). Significant association between cricoid cartilage findings (p=0.032, Cramer's V=0.318) or thyroid gland involvement on CT scan (p=0.018, Phi=0.384; OR 13 95% CI 1.797, 94.035) with thyroid gland involvement on final histopathology was noted. The rest of the variables had no significant association with thyroid gland involvement on final histopathology.

CONCLUSION

Cricoid cartilage involvement (erosion or invasion) and thyroid gland involvement on CT scan are associated with thyroid gland involvement on final histopathology in patients with laryngeal SCC. Patients with these CT scan findings may stand to benefit more from thyroidectomy to ensure good margins of resection.