title: Micromedullary thyroid cancer: how micro is truly micro?
abstract: BACKGROUND
  The aggressive nature of medullary thyroid cancer (MTC) is evidenced by its propensity to present early with lymph node (LN) metastases. The clinical significance of sporadic MTC < or =1 cm (micro-MTC) is not clearly defined.
  
  
  METHODS
  We performed a retrospective review of the clinical, laboratory, and pathologic data for all patients treated or followed at our institution for sporadic micro-MTC from 1987 through 2008.
  
  
  RESULTS
  A total of 18 patients met the criteria for inclusion in our study. All tumors were unifocal and C-cell hyperplasia distant from the tumors was uniformly absent. Fourteen (78%) patients underwent total thyroidectomy, and the remaining four (22%) patients with tumors < or =0.5 cm had lobectomy with isthmusectomy alone. Four (22%) patients were found to have LN metastases. However, none of the nine patients with tumors <0.5 cm had clinical evidence of LN metastases. Patients were followed for a median of 3.3 (mean, 4.5) years, and there were no deaths. Postoperative calcitonin levels were available for all patients, of whom 14 had normal levels (range, 0-3.9 pg/ml). The four patients with elevated postoperative calcitonin levels (range, 6.3-644 pg/ml) had tumors ranging from 0.7-0.9 cm in size.
  
  
  CONCLUSIONS
  Tumors <0.5 cm were associated with a complete absence of clinically detectable nodal disease or elevated postoperative calcitonin levels. The complete absence of multifocal or bilateral disease argues against the need for completion thyroidectomy for sporadic micro-MTC.
authors: Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors: Venu G
authors: VG
authors: Pillarisetty
authors: Steven C
authors: SC
authors: Katz
authors: Ronald A
authors: RA
authors: Ghossein
authors: R Michael
authors: RM
authors: Tuttle
authors: Ashok R
authors: AR
authors: Shaha
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D002116:Calcitonin / Q000378:metabolism; D018276:Carcinoma, Medullary / Q000473:pathology* / Q000601:surgery; D002291:Carcinoma, Papillary / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy; D016896:Treatment Outcome
chemical_list: D002116:Calcitonin