Objective:
The aim of the study is the determination of the accuracy of preoperative CT findings for larynx cancer and the reasons for false negatives and false positives regarding to the histopathological results.
Material and methods:
Preoperatively 94 patients were diagnosed with larynx cancer by biopsy. All patients were evaluated preoperatively with single detector CT and then operated. The pathology results were accepted as a reference method. Latest TNM scoring system was used for the CT staging.
Results:
Squamous cell carcinoma was confirmed in 92 of the patients, adenoid cystic carcinoma in 1 of the patients, and chondrosarcoma in one patient. The most common tumor was found transglottic (46.8%) and the least detected was the subglottic (1.1%). The anatomic level of the tumor in the CT was correctly detected in 37 of 44 patients (84%). The accuracy of the preepiglottic, the anterior commissur, and the subglottic extension and cartilage invasions were evaluated as 75%, 74%, 76% and 82% respectively. The histopathologic and CT results correlation was significantly positive in the advanced tumors (grade 3-4) (κ=0.4784, p<0.001). The lymph node invasion determination rate was found high. The TNM staging with CT was more successful for the advanced tumors (κ=0.465, p<0.001).
Conclusion:
The large and expansive transglottic tumors deteriorate the correct grading. While there is a higher grading accuracy in advanced nontransglottic tumors, in early stages the probable cause of overstaging depends on the peritumoral inflamation making the tumor appearance bigger. In advanced stages the probable misdiagnosis of paraglottic space or cartilage invasion is the cause of understaging.
Keywords: Larynx cancer, computed tomography, staging, pathology