During our 130-month study period, 109 patients with MTC underwent a neck operation at our institution; 50 (46%) met our inclusion criteria for evaluation. Our control group consisted of 50 randomly chosen patients who underwent a neck operation for PTC. We found no significant difference in age or race between patients the MTC and PTC patients, but there was a significant gender difference between both groups. Although women made up the majority of patients in both groups, there were disproportionally more women in the PTC control group than in the MTC study group (Table ). Most patients in both groups were asymptomatic, but 22% of those with MTC had neck pain at presentation, as compared with only 6% of those with PTC (p = 0.041). Only patients with MTC (2 of 50) had hoarseness; however, the difference between the 2 groups regarding this symptom was not statistically significant.
Patients with medullary thyroid cancer (MTC) vs. papillary thyroid cancer (PTC)
The final pathology test results regarding multifocality, capsular invasion, and vascular invasion did not significantly differ between the 2 groups. However, patients with MTC had a higher rate (20%) of lymphatic invasion than those with PTC (2%); this difference was significant (p = 0.008). Despite this increased risk of lymphatic invasion for MTC patients, their incidence of LN metastases was not higher than the incidence for PTC patients (Table ).
The stage of disease at presentation significantly differed between the 2 groups. Patients with MTC presented less often with stage I disease (32%), as compared with patients with PTC (72%) (p = 0.0001). Conversely, patients with MTC presented more often with stage IV disease (30%), as compared with patients with PTC (2%) (p = 0.0001). We found no difference between the 2 groups in terms of stage II and stage III at presentation.
Of the 50 patients with MTC, 11 (22%) had neck pain. Neck pain was distributed in the region of the thyroid gland, and no patient presented with neck pain from palpable lymphadenopathy. No patient with MTC presented with clinically palpable lymphadenopathy. Patients with (vs. without) neck pain tended to be older, but, the difference was not statistically significant (Table ). We found no statistical differences in gender and family history (inherited MTC, sporadic MTC, and sporadic MTC with somatic mutations) between the 2 groups. Similarly, we found no difference in preoperative ultrasound-proven lymphadenopathy between the 2 groups (Table ).
Patients with medullary thyroid cancer (MTC), with and without neck pain at presentation
No histologic differences per the final pathology test results were apparent between the 2 groups; the rate of multifocality, capsular invasion, vascular invasion, and lymphatic invasion were similar (Table ). However, patients with neck pain were more likely to have LN metastases (82%) than those without neck pain (36%); of which 7 of 9 (78%) patients with neck pain compared to 7 of 14 (50%) without neck pain had both central and ipsilateral lateral neck LN metastases. This difference was statistically significant (p = 0.014) and translated into a higher stage of disease. Of patients with neck pain, only 18% had either stage I or II disease, as compared with 64% without neck pain; however, 82% of patients with neck pain had stage III or IV disease, as compared with only 36% without pain (p = 0.014). In 3 patients without neck pain, we could not definitively determine the stage of disease.
Unlike in our MTC study group, the age of patients with vs. without neck pain differed in our PTC control group. Patients with PTC with (vs. without) neck pain were older (median age, 73.7 years with neck pain vs. 48.4 without, p = 0.019). As in our MTC study group, we found no difference in gender, genetic makeup, or histologic findings in our PTC control group (Table ). We also found no difference in our PTC control group in the incidence of LN metastases between patients with vs. without neck pain, nor did the stage of disease differ in any way between those 2 subgroups of patients with PTC (Table ).
Patients with papillary thyroid cancer (PTC), with and without neck pain at presentation