Carcinoma of the thyroid occurring in a diffuse toxic goiter

Hyperthyroidism and Concurrent Thyroid Cancer

Aims and Background

The aim of this study was to analyze the frequency of coexisting hyperthyroidism and thyroid malignancy in endemic goiter areas and review the current literature on the subject.

Methods

During the period January 1984 to June 1998, 1853 patients were examined for hyperthyroidism at the Spedali Civili Hospital of Brescia, Italy; 512 (27.6%) subjects underwent surgery. Of these patients 108 (21%) had Graves’ disease, 251 (49%) multinodular toxic goiter (MTG) and 153 (30%) uninodular toxic goiter (UTG).

Results

Malignancy was found in 24 (4.7%) patients: 19 females and 5 males with a mean age of 52.2 years (range, 21-76 years). The frequency of cancer in Graves’ disease was 6.4%, 5 females and 2 males; in MTG 3.9%, 2 females and 8 males, and in UTG 4.4%, 7 females and 1 male.

Conclusions

Our data confirm previous reports on the frequency of thyroid cancer in hyperthyroidism. This association is more relevant than previously suspected. The frequent coexistence of hyperthyroidism and neoplasia, demonstrated by our study and the most recent literature, underlines the importance of studying and excluding the possibility of neoplastic degeneration by means of a systematic approach.

Prevalence of incidental thyroid cancer and its ultrasonographic features in subcentimeter thyroid nodules of patients with hyperthyroidism

In patients, who undergo surgery for hyperthyroidism, many cases of incidental thyroid cancer (ITC) have been detected. In the literature, there is no study about ITC in subcentimeter nodules in these patients. We performed this study to determine the frequency of ITC in subcentimeter nodules and ultrasonographic features that can predict malignancy in the patients with hyperthyroidism. We retrospectively reviewed our database about 3114 patients, who underwent thyroidectomy in our hospital. Among 869 patients (27.9%), who were operated because of hyperthyroidism, we enrolled 337 patients, who underwent total thyroidectomy and had subcentimeter nodule [59 Graves’ disease (GD) 98 subcentimeter nodule; 278 toxic multinodular goitre (TMNG), 359 subcentimeter nodule], in this study. Twenty-five nodules with ITC and 432 benign nodules have been detected and compared for ultrasonographic (US) features. Incidental thyroid cancer detection ratio was 5.4% [10.2% (10/98) in subcentimeter thyroid nodules in individuals with GD, and 4.1% (15/359) in individuals with TMNG, P = 0.018)]. Significant differences have been observed between the groups in terms of microcalcification in US examination of malign and benign subcentimeter thyroid nodules and the ratio of anterioposterior diameter to transverse diameter (A/T) ≥1 [(OR = 5.172; 95% CI: 1.495–17.886, P = 0.015), and (OR = 5.930; 95% CI: 1.531–22.971, P = 0.007), respectively]. We detected a higher incidence of ITC in subcentimeter thyroid nodules in GD compared to TMNG. US examination of subcentimeter nodules in hyperthyroid individuals has indicated that microcalcification and ratio of A/T ≥1 are the parameters that predict malignancy.

Outcome of Patients Surgically Treated for Various Forms of Hyperthyroidism with Differentiated Thyroid Cancer: Experience at an Endocrine Center in Italy

PURPOSE

The incidence and aggressiveness of thyroid cancer associated with hyperthyroidism remains a subject of much controversy. The aim of this study was to analyze the frequency of coexisting hyperthyroidism and thyroid cancer, and to determine whether cancer becomes more aggressive with different forms of hyperthyroidism.

METHODS

We retrospectively studied 2,449 patients assessed for hyperthyroidism between 1985 and 2001. All patients with a "cold" nodule on scintigraphy, such as those with Graves' disease and a concomitant solid nodule, underwent fine-needle aspiration biopsy (FNAB). Criteria for surgery were cytological findings indicative of malignancy, goiter with signs of tracheal or esophageal compression, side effects of antithyroid drug therapy, or Graves' disease with multiple relapses after therapy withdrawal or responsiveness to antithyroid drugs.

RESULTS

Thyroid cancer was diagnosed more frequently in patients with Graves' disease (6.5%) than in those with uninodular toxic goiter (UTG) (4.4%) or multinodular toxic goiter (MTG) (3.9%). Lymph node involvement was found in 56% of the patients with Graves' disease, in 23% of those with MTG, and in none of those with UTG. Distant metastases were found in one patient with Graves' disease.

CONCLUSIONS

Cancers associated with Graves' disease seems to be more aggressive than those associated with MTG or UTG. Thus, we suggest that patients with Graves' disease be carefully monitored for the detection of thyroid nodules. Ultrasonography seems to be the best modality to detect such nodules.

Thyroid carcinoma in Graves' disease

The pathogenesis of thyroid carcinoma in Graves' goiter is still obscure and the methods for preoperative diagnosis of such carcinomas is not well established. We studied the incidence, clinical features, and pathological findings of thyroid carcinoma in Graves' goiter. From October, 1983 to September, 1985, a total of 739 patients with Graves' disease underwent subtotal thyroidectomy at Ito Hospital, Tokyo. All of these patients underwent roentgenography of the neck before surgery. Thyroid carcinoma was revealed in the resected specimen in 15 (2.0%) of 739 patients. During the same period, another 4 patients underwent surgery for thyroid carcinoma who had had Graves' disease previously and these 4 cases were included in the present study. The incidence of thyroid carcinoma associated with Graves' disease was 2.6% (19 of 743 cases). Histological examination revealed 15 papillary and 4 follicular carcinomas. The size of the carcinoma foci was 13.8 +/- 15.6 mm in diameter (range: 1-60 mm), 10 (52.6%) foci being 10 mm or greater. Invasive growth into the surrounding thyroid tissue was predominant and regional lymph node metastasis was noted in all 6 patients who underwent cervical dissection. Preoperative roentgenography revealed calcification in 5 (26.3%) of 19 cases. Our present study indicates that thyroid carcinoma in Graves' goiter may show markedly invasive growth with lymph node metastasis even though the primary tumor is small in size, and it is suggested that the detection of calcification may serve as a part of the diagnostic measures when the carcinoma focus is difficult to palpate in the diffusely-enlarged Graves' goiter.

Thyroid carcinoma in thyrotoxic patients treated by surgery

We report the incidence of thyroid cancer in a series of 1832 consecutive patients seen for thyrotoxicosis of any etiology during 1970 and 1985 in our department. Surgical treatment for thyrotoxicosis was selected as the treatment of choice in 179 patients (9.8%), 86 with toxic diffuse goiter (TDG), 21 with toxic nodular goiter (TNG) and 40 with toxic adenoma (TA). The presence of thyroid cancer was found in 11 patients for a total incidence of 6.1%. Six patients had TDG (percent incidence in this group 6.9%), 4 patients had TNG (7.5%) and 1 had TA (2.5%). While the presence of thyroid cancer was totally unsuspected in TNG and TA, in TDG 4 out of 6 patients found to have a cancer, had been suspected before surgery. When a thyroid nodule was present in a toxic diffuse goiter the possibility to face with a malignant lesion reached 22.2% of the cases (4 out of 18 cases), while only 2 out of 68 patients (2.9%) with TDG and no nodule had thyroid cancer. These results confirm recent other series reporting the frequent association of hyperthyroidism and thyroid cancer and suggest that in thyrotoxic patients any nodule must be screened carefully to rule out malignancy.