ENCAPSULATED PAPILLARY NEOPLASM OF THE THYROID - RETROSPECTIVE CLINICOPATHOLOGICAL STUDY WITH LONG-TERM FOLLOW-UP

Objective: To study the clinical course of patients with the encapsula ted variant of papillary thyroid carcinoma, in which there is a well-d efined fibrous wall completely separating the tumour cells from the ad jacent tissue. Design: Retrospective review. Setting: University hospi tal, Spain. Subjects. Of a total of 163 patients whose papillary thyro id carcinomas were treated surgically between 1975 and 1985, there wer e 25 encapsulated tumours. Main Outcome Measures: Clinicopathological features and survival rate compared with those of non-encapsulated pap illary thyroid carcinomas. Results: Mean follow up was 9 years (range 7-17), and 42 were excluded because follow up was incomplete. Encapsul ated tumours differed from the earlier age of other types in that they presented earlier (mean age 36 years compared with 45), they were sig nificantly less likely to have symptoms of compression (1/25 compared with 24/96, p = 0.024), or nodal metastases (3/25 compared with 43/96, p = 0.002), or to recur (0/25 compared with 33/96, p = 0.002). No pat ients died in the encapsulated group compared with 11/96 in the other group. Conclusions: Encapsulated papillary carcinomas have an excellen t prognosis, and can be cured by operation.