[Results of selective venous site-specific catheterization in occult C-cell carcinoma of the thyroid gland].

Background: Medullary thyroid carcinoma (MTC) can--even in recurrent cases--only be treated surgically. Therefore, preoperative localization of the tumor is essential.

Methods: From April 1986 through April 1997, 137 patients with MTC were operated on at our clinic. In 22 patients with recurrent tumor which had not been radiologically localized, 28 selective venous catheterizations (SVC) with determination of calcitonin levels were carried out.

Results: In 23 examinations a suspected tumor could be identified (nine cervical unilateral, seven mediastinal, four cervical unilateral and mediastinal, one cervical bilateral and mediastinal, one liver, one cervical unilateral and liver). In 18 cases surgery was performed for recurrence (nine cervical revisions, one mediastinal dissection, six cervicomediastinal dissections, two laparotomies). In 15 of 18 cases, tumor tissue was found in the previously suspected area. In ten cases serum calcitonin levels dropped postoperatively by 6%-75%. A normalization of the hormone level was achieved only once by yet another operation. During further follow-up, five of the reoperated patients died from their disease. The other 17 patients are being followed up, whereby calcitonin levels are elevated but there is no clinical or radiological evidence of tumor.

Conclusions: Although in the patient cohort presented a normalization of serum calcitonin could be achieved only once, the authors consider SVC useful because it is the only means of localization of tumor tissue in cases of negative radiologic studies and therefore allows a planned approach to the operation procedure in these cases.