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Thyroid and Parathyroid Glands

Cernea CR, Dias FL, Fliss D, Lima RA, Myers EN, Wei WI (eds): Pearls and Pitfalls in Head and Neck Surgery. Basel, Karger, 2012, pp 28–29

DOI: 10.1159/000337471

1.14 Management of Lymph Nodes in Medullary Thyroid Cancer

Marcos R. Tavares

General Hospital, University of São Paulo, School of Medicine, São Paulo, Brazil

P E A R L S

• Lymph node metastases (LNM) are frequent in clinical medullary thyroid cancer (MTC; 70%) and surgery is the only curative treatment.

• The option for neck dissection is dictated by preoperative evaluation.

• Preoperative thyroid and lymph node evaluation by high-resolution ultrasound is mandatory.

• Therapeutic lateral neck dissection (LND; levels II-VII) is always useful.

• Elective central compartment dissection (CCD) is indicated for palpable thyroid tumor, for recurrent disease, or when basal calcitonin level is >40 pg/ml in patients with hereditary MTC.

• Neck reoperation is indicated only for proven disease.

• Parathyroid glands are to be identified during thyroidectomy.

P I T F A L L S

• Inadequate clinical and pathological evaluation of the neck.

• Elective CCD in RET carriers with normal pretreatment basal calcitonin levels.

• Incomplete CCD.

• ‘Berry picking' removal of at-risk or involved lymph node basins.

• RET test not performed in patients with MTC and first-degree relatives of individuals with positive test.

• Dissection of the lateral neck without disease localization.

Introduction

MTC occurs in sporadic or familial clinical settings and corresponds to 5% of thyroid carcinomas and as much as 63% present initially with LNM [1]. The adequate treatment of MTC is total thyroidectomy and removal of all neoplastic tissue in the neck [2]. Cervical LNM are an independent risk factor for worse survival rate in MTC. Only 10-40% of pN+ patients are cured [3]. Neck dissection is important for regional disease control and patient staging [4], and mandatory when LNM are clinically evident.

Clinical evaluation must be followed by expert neck ultrasound exam. Metastases must be confirmed by fine needle aspiration biopsy complemented with calcitonin dosage in the wash out of the fine needle aspiration biopsy product [5].

Total thyroidectomy and elective CCD is advocated if there is clinically detected MTC >5 mm and/or basal calcitonin level >40 pg/ml. In RET carriers with normal pretherapeutic basal calcitonin levels and no evidence of neck disease, elective CCD is not necessary [6, 7].

Most neWIy diagnosed MTC patients present with pretherapeutic basal calcitonin levels greater than 200 pg/ml and may need bilateral LND to reduce the number of reoperations [8].

Less aggressive neck surgery, preserving respiratory, swallowing, and parathyroid functions is recommended for patients with locally advanced disease and/or with distant metastasis [9]. In these situations, total thyroidectomy and CCD is the minimal treatment [10].

Practical Tips

CCD must be considered in all patients with clinical disease to avoid the harms of reoperation. The exceptions are MEN 2A or FMTC patients with low-risk RET mutation, without evidence of LNM, under the age of 5 years, and with basal calcitonin <40 pg/ml. All tissue between the carotid arteries, laterally, and between the hyoid bone and the brachiocephalic venous trunk needs to be removed.

Parathyroid glands are identified during the thyroidectomy, but hypoparathyroidism is common after CCD. It is advisable to remove and transplant a damaged parathyroid gland, or if a parathyroid adenoma is found and in carriers of high-risk RET mutation [10].

Therapeutic LND can be safely staged.

Reoperation is an option if calcitonin does not reach a low level. However, LND is performed only for LNM confirmed by fine needle aspiration. Distant metastases do not rule out neck dissection because it is the only effective tool to control disease in the neck. The imaging work-up for depicting MTC tumor consists of neck ultrasound, chest CT, liver MRI, bone scintigraphy, and axial skeleton MRI. PET/CT is a sensitive imaging tool for MTC recurrence, especially in patients with high calcitonin levels [11].

References

1 Moley JF, DeBenedetti MK: Patterns of nodal metastases in palpable medullary thyroid carcinoma. Recommendations for extent of node dissection. Ann Surg 1999;229:880–888.

2 Pacini F, Castagna MG, Cipri C, Schlumberger M: Management of lymph nodes in medullary thyroid cancer (MTC). Clin Oncol (R Coll Radiol) 2010;22:475–485.

3 Tavares MR, Michaluart P Jr, Montenegro F, Arap S, Sodre M, Takeda F, Brandao L, Toledo S, Ferraz A: Skip metastases in medullary thyroid carcinoma: a single-center experience. Surg Today 2008;38:499–504.

4 American Thyroid Cancer Guidelines Taskforce: Kloos RT, Eng C, Evans DB, Francis GL, Gagel RF, Gharib H, et al: Medullary thyroid cancer: management guidelines of the American Thyroid Association. Thyroid 2009;19:565–612.

5 Tincani AJ, Teixeira GV, Tavares MR, Hojaij FC, Araújo PPC, Maia AL, Ward LS, Kimura ET, Del Negro A, Friguglieti CUM, Cernea C, Montenegro F, Dias FL, Corrêa LAC, Kulcsar MAV, Pedruzzi P, Santos RO, Puñales MK, Caldas G, Miyahara L, Pereira SAM, Pereira EM, Marone M, Brandão RC, Soares J Jr, Stein AT, Andrada NC: Diretrizes da AMB Câncer Medular da Tireóide: Tratamento 31 de outubro de 2009. http://www.projetodiretrizes.org.br/ans/diretrizes/cancermedulardetireoide-tratamento.pdf.

6 Kandil E, Gilson MM, Alabbas HH, Tufaro AP, Dackiw A, Tufano RP: Survival implications of cervical lymphadenectomy in patients with medullary thyroid cancer. Ann Surg Oncol 2011;18:1028–1034.

7 Machens A, Lorenz K, Dralle H: Individualization of lymph node dissection in RET (rearranged during transfection) carriers at risk for medullary thyroid cancer: value of pretherapeutic calcitonin levels. Ann Surg 2009;250:305–310.

8 Machens A, Dralle H: Biomarker-based risk stratification for previously untreated medullary thyroid cancer. J Clin Endocrinol Metab 2010;95:2655–2663.

9 Pelizzo MR, Boschin IM, Bernante P, Toniato A, Piotto A, Pagetta C, et al: Natural history, diagnosis, treatment and outcome of medullary thyroid cancer: 37 years experience on 157 patients. Eur J Surg Oncol 2007;33:493–497.

10 Brandi ML, Gagel RF, Angeli A, Bilezikian PB, Bordi C, Conte-Devolx B, Flachetti A, Gheri RG, Libroia A, Lips CJ, Lombardi G, Mannelli M, Pacini F, Ponder BA, Raue F, Skoqseid B, Tamburrano G, Thakker RV, Thompson PT, Tonelli F, Wells S Jr, Marx SJ: Guidelines for diagnosis and therapy of MEN type 1 and type 2. J Clin Endocrinol Metabol 2001;86:5568–5571.

11 Ozkan E, Soydal C, Kucuk ON, Ibis E, Erbay G: Impact of ¹⁸ F-FDG PET/CT for detecting recurrence of medullary thyroid carcinoma. Nucl Med Commun 2011;32:1162–1168.

Marcos Roberto Tavares

General Hospital

University of São Paulo

School of Medicine

Rua Joaquim Floriano, 101 -cj. 601

São Paulo, SP 04534-010 (Brazil)

E-Mail mtavares@apm.org.br