| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
ORIGINAL ARTICLES |
From the Division of General Surgery, Department of Surgery (T-CC, M-FC), and Division of Metabolism and Endocrinology, Department of Internal Medicine (J-DL), Chang Gung University College of Medicine and Chang Gung Memorial Hospital, Taoyuan, Taiwan.
Correspondence: Address correspondence and reprint requests to: Tzu-Chieh Chao, MD, PhD, Department of Surgery, Chang Gung Memorial Hospital, 5 Fuhsing St., Kweishan, Taoyuan, Taiwan; Fax: 886-3328-5818; E-mail: tcchao{at}adm.cgmh.org.tw
| ABSTRACT |
|---|
|
|
|---|
Methods: Sixty-one thyroid cancers with concurrent Graves disease were retrospectively reviewed. Histopathologic diagnoses included 58 papillary thyroid carcinomas (95.1%), 1 follicular carcinoma (1.6%), 1 medullary carcinoma (1.6%), and 1 Hürthle cell carcinoma (1.6%).
Results: The sample included 54 females and seven males. Subjects ages ranged from 20 to 73 years (mean ± SD, 35.9 ± 10.6 years; median, 37 years). Average tumor size was 10.7 ± 15.9 mm (range, 170 mm). Forty-nine tumors (80.3%) were 10 mm or smaller. Surgical procedures included subtotal thyroidectomy (40 patients), total thyroidectomy (16 patients), total thyroidectomy plus neck dissection (2 patients), near-total thyroidectomy (1 patient), and lobectomy with contralateral subtotal lobectomy (1 patient). Thirty-seven patients (60.7%) underwent postoperative 131I ablation for thyroid remnant. Neck lymph node metastases occurred in three patients and lung metastases in two patients. Patients who developed metastases were younger and had significantly larger tumors and higher pretreatment serum T3 level than those who did not develop metastases. No deaths occurred during the 6.2 ± 4.1 year follow-up period (range, 1 year and 2 months to 18 years and 11 months).
Conclusions: Most thyroid cancers with concurrent Graves disease were 10 mm or smaller. Subtotal thyroidectomy is adequate for patients with Graves disease with concurrent carcinoma 10 mm or smaller.
Key Words: Carcinoma Graves disease Incidentaloma Thyroid Thyroidectomy Thyrotoxicosis
| INTRODUCTION |
|---|
|
|
|---|
| MATERIALS AND METHODS |
|---|
|
|
|---|
Patients were treated with propylthiouracil, carbimazole, or methimazole before surgery. Moreover, patients also received Lugol solution for 7 to 10 days during the immediate preoperative period. The indications for surgery for patients with Graves disease included recurrent thyrotoxicosis; side effects of antithyroid medications; low likelihood of taking or inability to take medication; cold nodules within toxic glands on thyroid scanning; unusually large diffuse goiters; and malignancy or suspected cytological findings following fine-needle aspiration biopsy.
Sixty-one (2.0%) of 3112 patients with Graves disease had concurrent thyroid carcinoma. Thirty of these 61 patients were reviewed in our previous study.13 None of these patients had a history of previous neck irradiation or radioiodine therapy. Tumor size was the maximum dimension measured on pathological examination. In carcinomas with multiple foci, the maximum dimension of tumor foci was taken as the tumor size. Small tumors were defined as those 10 mm or smaller, whereas large tumors exceeded 10 mm.
| RESULTS |
|---|
|
|
|---|
|
Forty-two patients (68.9%) underwent technetium-99m (99mTc) sodium pertechnetate thyroid scanning before surgery, which revealed that 25 (59.5%) had toxic diffuse goiters, 10 (23.8%) had toxic diffuse goiters with a coexistent cold nodule, 6 (14.3%) had toxic multinodular goiters, and 1 (2.4%) had subacute thyroiditis. Thirty-three patients (54.1%) underwent preoperative thyroid ultrasonography with fine-needle aspiration cytology (FNAC) owing to the appearance of cold nodules on the thyroid scan or the presence of clinically palpable nodules.
FNAC revealed papillary carcinoma in three patients (9.1%) and revealed suspected malignancy in five (15.2%). Meanwhile, FNAC for the remaining patients yielded the following findings: 1 patient (3.0%), Hürthle cell tumor; 1 (3.0%), follicular neoplasm; 15 (45.5%), autoimmune thyroid diseases; and 8 (24.2%), benign thyroid lesions. That is, only 10 patients (30.3%) had FNAC findings indicating a need for surgical treatment. Twenty-one patients (34.4%) underwent intraoperative frozen-section examination for nodules. Frozen-section histology confirmed malignancy in 15 patients (71.4%) with papillary carcinoma and one (4.8%) with Hürthle cell carcinoma. Frozen-section analysis revealed no malignancy in the remaining five patients (23.8%).
Table 2 lists the surgical methods for thyroid cancer patients with concurrent Graves disease. Subtotal thyroidectomy was the most common surgical method, particularly for incidentalomas. Total thyroidectomy and near-total thyroidectomy were conducted following frozen-section diagnosis of malignancy. One patient with an incidentaloma and three with clinically overt tumors were initially treated by subtotal thyroidectomy followed by completion thyroidectomy after permanent section diagnosis of malignancy. Additionally, two patients who were initially treated by lobectomy and contralateral subtotal lobectomy on the basis of frozen section diagnoses of benign lesions declined subsequent completion thyroidectomy. Operative morbidity included transient hypoparathyroidism (one patient, 1.6%), permanent hypoparathyroidism (three patients, 4.9%), and transient recurrent laryngeal nerve palsy (two patients, 3.3%).
|
The follow-up period ranged from 1 year and 2 months to 18 years and 11 months (median, 5.1 years; mean ± SD, 6.2 ± 4.1 years). No deaths occurred during follow-up. Five patients (8.2%) suffered metastases to the lungs or neck lymph nodes. Of these five patients, two patients with clinically overt nodules (one large papillary carcinoma and one small papillary carcinoma) had lung metastases 11 months and 2 years after near-total and total thyroidectomy. These two patients were treated with 3700 to 5550 MBq 131I and remained alive with persistent disease at final follow-up.
Two patients with incidentalomas had metastases to neck lymph nodes, at 11 months and at 2 years and 3 months after subtotal thyroidectomy. These two patients underwent neck dissection followed by either radioiodine treatment or external radiation and remained disease-free until final follow-up. Finally, one patient with large papillary carcinoma had neck lymph node metastases 11 months following total thyroidectomy. This patient declined repeat surgery for metastatic lymph nodes and subsequently was treated with radioiodine. This patient remained alive with the disease 4 years and 5 months after initial thyroidectomy.
Table 3 lists characteristics in patients with or without metastases. Patients with metastases were younger and had significantly larger tumors than did patients without metastases. Moreover, serum T3 levels before antithyroid medications in patients with metastases significantly exceeded those in patients without metastases. Age, premedication serum T4 level, and 6-week postoperative serum levels of thyroglobulin and TSH in patients with metastases did not differ between patients with and without metastases. Furthermore, postoperative 131I ablation and the extent of surgery were not associated with metastases.
|
| DISCUSSION |
|---|
|
|
|---|
Treatment options for Graves disease include antithyroid drugs, radioactive iodine therapy, and surgery.1720 Although the policy for treating Graves disease varies markedly within and between different countries, the presence or otherwise of concomitant thyroid nodules might be considered when treatment is determined. In Graves disease, 10% to 17.1% of all nodules8,12,21 and 15.4% to 45.8% of scintigraphically cold nodules are malignant.4,9,12,22 Therefore, some investigators recommend surgical treatment for patients with Graves disease concomitant with nodules.9,18 However, nodules located deeply or in the context of a goiter often escape detection during physical examination by an experienced clinician.23 Nonpalpable nodules represent around 58.5% to 78.7% of the thyroid nodules identified by ultrasonography or thyroid scintigraphy in Graves disease.8,9,23,24
Accordingly, many authors recommend that patients with Graves disease should undergo examination of the thyroid gland not only by palpation but also by thyroid scintigraphy or ultrasonography.9,12,2426 Thyroid scintigraphy revealed cold nodules in only 23.8% of the patients in the present study, a finding suggesting that nodules in Graves disease are rarely detected by this method. This suggestion is consistent with the literature reports that thyroid scintigraphy detects cold nodules in only 5.8% to 12.0% of cases of Graves disease.8,9,12 On the other hand, ultrasonography can detect nodules more frequently in Graves disease than can thyroid scintigraphy, with an incidence of 20.8% to 33.7%.8,24 FNAC is applied to differentiate benign from malignant nodules in Graves disease.24,27 However, this study did not show FNAC to be particularly useful for diagnosing malignancy in patients with Graves disease. The reason for this phenomenon is that the malignant nodules in Graves disease are generally small.5,6
FNAC is difficult for small nodules and carries the risk of hemorrhage in a Graves goiter. Additionally, the hyperplastic tissues associated with Graves disease may increase the cytological diagnosis of follicular neoplasm.12 Consequently, given the suggestion of an increased cancer risk in nodules concomitant with Graves disease, this study sets a low threshold for nodule referral for surgery, unless an expert cytologist concludes by means of FNAC that cancer is highly unlikely.
The extent of surgery for thyroid carcinoma concomitant with Graves disease has rarely been discussed. Some researchers have reported that thyroid cancers associated with Graves disease behave aggressively, with a tendency toward a high frequency of lymph node metastases, found both at surgery and as a cause of recurrent locoregional disease.4,6,9,10 Accordingly, total, near-total,10 or subtotal thyroidectomy9 plus central neck dissection was recommended for treating this disease. In contrast, most of the present group of patients underwent subtotal thyroidectomy, and, moreover, it was observed that the extent of thyroidectomy did not influence the incidence of metastases. In the present study, although three small tumors developed metastases, the median size of tumors developing metastases was larger than that of tumors that did not develop metastases (Table 3). The measured results are consistent with reports of others that, in Graves disease, larger thyroid cancers are more aggressive4,10 and smaller tumors have a more favorable prognosis.10
Most carcinomas associated with Graves disease in the present study and in the literature5,6,10 are small and found incidentally during postoperative pathological examination of the thyroid or during surgery. Noguchi et al.28 showed that carcinomas smaller than 10 mm concomitant with Graves disease can be treated by subtotal thyroidectomy with excellent outcomes. Similar results also have been noted in euthyroid patients. Although some authors have reported that thyroid papillary carcinomas 10 mm or smaller may follow an aggressive course,29,30 most researchers have found that most small thyroid carcinomas have an excellent prognosis and can be treated with surgery less extensive than total or near-total thyroidectomy.28,3136
Ablation of thyroid remnant with 131I is generally performed in euthyroid patients with well differentiated thyroid carcinomas following total or near-total thyroidectomy,37,38 in response to the finding of a significant reduction in recurrence and cancer-related deaths in patients treated with 131I therapy.14,39 There have been few reports of postoperative 131I ablation for thyroid carcinomas concomitant with Graves disease.5,7 Most carcinomas in Graves disease are small tumors that were found incidentally following surgery. Patients with thyroid carcinomas concomitant with Graves disease are usually treated by subtotal thyroidectomy for Graves disease.
Accordingly, a key question is whether these patients should undergo 131I ablation following subtotal thyroidectomy or whether they should undergo other less extensive procedures. The present study found that 131I ablation of thyroid remnant did not influence the incidence of metastases. A recent study of 867 patients with thyroid carcinomas smaller than 10 mm included 541 patients (62.4%), including 414 with Graves disease, treated by subtotal thyroidectomy.28 Postoperative 131I ablation was not administered to these patients in the absence of metastases, and the sample group had a high recurrence-free survival rate. Similar findings were observed in euthyroid patients with papillary microcarcinoma of the thyroid.28,36,40,41 Consequently, routine 131I ablation is not necessary in patients with Graves disease with small thyroid carcinoma.
In conclusion, most thyroid cancers with concurrent Graves disease were 10 mm or smaller. Patients who developed metastases were younger and had larger tumors and higher pretreatment serum concentration of T3 than those who did not develop metastases. Cold nodules on thyroid scan suggest the possibility of thyroid carcinomas in Graves goiter, and these need to be treated surgically. Subtotal thyroidectomy is adequate for patients with Graves disease with concurrent carcinoma 10 mm or smaller. Moreover, postoperative 131I ablation of thyroid remnant generally is unnecessary for patients with small tumors.
| FOOTNOTES |
|---|
Received for publication June 18, 2003. Accepted for publication December 21, 2003.
| REFERENCES |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
K. Pazaitou-Panayiotou, P. Perros, M. Boudina, G. Siardos, A. Drimonitis, F. Patakiouta, and I. Vainas Mortality from thyroid cancer in patients with hyperthyroidism: the Theagenion Cancer Hospital experience Eur. J. Endocrinol., December 1, 2008; 159(6): 799 - 803. [Abstract] [Full Text] [PDF] |
||||
![]() |
Q.-Y. Duh Editorial: Thyroid Cancer in Graves Disease: Incidental Cancer Versus Clinical Cancer Ann. Surg. Oncol., April 1, 2004; 11(4): 356 - 357. [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |