title: Papillary microcarcinoma and papillary cancer of the thyroid <or=1 cm: modified definition of the WHO and the therapeutic dilemma.
abstract: OBJECTIVE
  Major controversies exist regarding the treatment of papillary microcarcinoma of the thyroid (PMC). Prior to 2003 PMC was defined by the WHO as a papillary carcinoma of 1 cm or less in diameter. In 2004 that definition changed, with the new classification requiring that the tumour also must be found incidentally.
  
  
  METHODS
  In this study we reviewed the clinical records of 67 patients with papillary tumours of the thyroid <or=1 cm, taking into account the new WHO definition (54 pts. with incidentally found PMC, median age: 53 years, 13 pts. with suspicion of thyroid neoplasm before resection, median age: 38 years). Clinical presentation, surgical treatment, further therapy and follow-up are presented.
  
  
  RESULTS
  Median tumour size was 7 mm in both groups (1-10 mm). Multicentric tumours were found in 15 pts. (22%), 8 had more than one PMC on the same side, and 7 displayed PMC bilaterally. Eleven (16%) of the primary tumors had metastatic involvement of regional lymph nodes at the time of initial surgery or during follow-up. Two patients showed distant metastases. No correlation between tumour size and multifocality or the presence of lymph node metastases could be seen. The gender of patients was the only significant independent variable for all patients; age and lymph node involvement was significantly different between incidentally and non-incidentally found PMC.
  
  
  CONCLUSIONS
  Despite the majority of patients with PMC having an excellent outcome, there are also cases showing an unfavorable course. Currently no predictive parameter exists to anticipate the course and long-term outcome for an individual patient. Until this problem is solved, each patient should have the option to decide for him or herself whether to be treated similarly or differently than for conventional thyroid cancer.
authors: Department of Nuclear Medicine, University of Regensburg, 93042 Regensburg, Germany. johann.schoenberger@klinik.uni-regensburg.de
authors: J
authors: J
authors: Schönberger
authors: J
authors: J
authors: Marienhagen
authors: A
authors: A
authors: Agha
authors: S
authors: S
authors: Rozeboom
authors: E
authors: E
authors: Bachmeier
authors: H
authors: H
authors: Schlitt
authors: C
authors: C
authors: Eilles
mesh_terms: D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D010212:Papilloma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome
chemical_list: D007457:Iodine Radioisotopes