[Lymph node dissection in papillary and follicular thyroid cancer]. / Lymphknotendissektion beim papillären und follikulären Schilddrüsenkarzinom.

BACKGROUND: There is still unresolved debate about the optimal surgical management of papillary (PTC) and follicular (FTC) thyroid cancer regarding lymph node dissection. So far the German guidelines recommend the same extent of surgery for both tumors. PATIENTS AND METHODS: This study is based on 626 patients with PTC and 191 with FTC from a group of 1062 own patients with thyroid malignancies. The extent of surgery, tumor size, and pN status were analysed. The results were compared with those in the current literature. RESULTS: Tumors < or = 20 mm in size were found significantly more often in PTC than FTC (69.6% vs 28.3%, P<0.05). Positive lymph nodes were found significantly more often in PTC than FTC as well (33.2% vs 5.2%, P<0.05). In PTC up to 10 mm and from 11 mm to 20 mm in size, 16% and 34.4% of patients, respectively, showed positive lymph nodes. In FTC positive lymph nodes occurred only in tumors >25 mm. CONCLUSION: Due to prevalence and importance of lymph node metastasis differing between PTC and FTC, we recommend treating both tumor entities differently. For PTC a more extended lymph dissection is necessary, even in tumors < or = 20 mm. In small FTC it seems adequate to limit the operation to thyroidectomy without prophylactic lymph dissection.