Medullary thyroid microcarcinoma recommendations for treatment - a single-center experience.
BACKGROUND
Conflicting recommendations exist regarding lymph node (LN) surgery in microMTC (<or=10mm). This study aims to correlate biochemical and pathohistological findings in an attempt to define the characteristics of microMTC, thus allowing recommendations for LN surgery.


METHODS
Patients with elevated basal (bCT:>or=10pg/ml) and pentagastrin-stimulated calcitonin levels (sCT:>100pg/ml) were selected for initial surgery. None of the patient was a member of any known MTC family. Biochemical and morphological data of microMTC were compared with 146 patients with C-cell hyperplasia (CCH).


RESULTS
MicroMTC (tumor diameter: 4.2+/-2.6mm; unifocal:68; multifocal:29) was documented in 97 of 159 (61%) MTC patients. In 11 (11%) patients, 1-19 LNs were involved. Correlating bCT and sCT levels neither predicted N-stage, nor differentiated between microMTC and CCH.


CONCLUSIONS
The biochemical discrimination cannot be made between patients with CCH and MTC, and patients with MTC with/without LN metastasis. Thus, thyroidectomy and central neck dissection is indicated in patients with "mildly" elevated sCT levels (<560pg/ml) (LN positive: 1 of 37 patients [2.7%]). A lateral neck dissection may be added "on demand" (in the setting of measurable postoperative bCT and/or sCT levels indicating LN metastasis). Patients with "highly" elevated sCT (>or=560pg/ml) must be treated as "palpable" MTC (LN positive: 10 of 54 patients [18.5%]).
Section of Endocrine Surgery, Division of General Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria. christian.scheuba@meduniwien.ac.at
Christian
C
Scheuba
Klaus
K
Kaserer
Christian
C
Bieglmayer
Reza
R
Asari
Phillip
P
Riss
Ralph
R
Drosten
Bruno
B
Niederle
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002116:Calcitonin / Q000097:blood; D018276:Carcinoma, Medullary / Q000235:genetics / Q000556:secondary* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology / Q000601:surgery; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D010418:Pentagastrin; D010641:Phenotype; D011446:Prospective Studies; D012720:Severity of Illness Index; D013964:Thyroid Neoplasms / Q000235:genetics / Q000473:pathology* / Q000601:surgery*; D013965:Thyroidectomy / Q000379:methods*
D002116:Calcitonin; D010418:Pentagastrin