[Differentiated thyroid carcinoma. Surgery and significance of lymph node involvement].

Introduction: Nodal treatment in papillary (PTC) and in follicular (FTC) thyroid carcinoma is still a subject of debate.
Methods: 1974-95 therapeutic lymphadenectomy (30/95), 1996-1999 frequent prophylactic lymphadenectomy (32/57; P = 0.005) was used for PTC, with therapeutic lymphadenectomy for FTC (15/115). 131I was used selectively for pN1-tumours.
Results: PTC: The incidence of pN0-, but not of pN1-status increased significantly (P = 0.03). Nodal recurrence was observed in 5/89 (6%) with therapeutic, vs. 1/54 (2%) with prophylactic lymphadenectomy (P = NS), i.e. in 1/107 (0.9%) patients without evidence of nodal disease, vs. 5/36 (14%) of those with pN1-status (P = 0.0004). Survival at 25 yrs. in stages TNM I and II was 100%, i.e., independent of N-status. FTC: No nodal recurrence was observed.
Conclusion: Occult untreated nodal disease represented no major clinical problem. Selective nodal treatment may offer optimal results; meticulous nodal dissection is indicated for N1-tumours.