Carcinoma of the thyroid in children

Radiation-Related Thyroid Cancer

Radiation is an environmental factor that elevates the risk of developing thyroid cancer. Actual and possible scenarios of exposures to external and internal radiation are multiple and diverse. This article reviews radiation doses to the thyroid and corresponding cancer risks due to planned, existing, and emergency exposure situations, and medical, public, and occupational categories of exposures. Any exposure scenario may deliver a range of doses to the thyroid, and the risk for cancer is addressed along with modifying factors. The consequences of the Chornobyl and Fukushima nuclear power plant accidents are described, summarizing the information on thyroid cancer epidemiology, treatment, and prognosis, clinicopathological characteristics, and genetic alterations. The Chornobyl thyroid cancers have evolved in time: becoming less aggressive and driver shifting from fusions to point mutations. A comparison of thyroid cancers from the 2 areas reveals numerous differences that cumulatively suggest the low probability of the radiogenic nature of thyroid cancers in Fukushima. In view of continuing usage of different sources of radiation in various settings, the possible ways of reducing thyroid cancer risk from exposures are considered. For external exposures, reasonable measures are generally in line with the As Low As Reasonably Achievable principle, while for internal irradiation from radioactive iodine, thyroid blocking with stable iodine may be recommended in addition to other measures in case of anticipated exposures from a nuclear reactor accident. Finally, the perspectives of studies of radiation effects on the thyroid are discussed from the epidemiological, basic science, and clinical points of view.

Higher Complication Rates for Total versus Partial Thyroidectomy in the Pediatric Population

INTRODUCTION

This study aims to analyze the relative risks for total thyroidectomies by comparing complication rates for total versus partial thyroidectomy in the pediatric population.

METHODS

We queried the Kids' Inpatient Database (KID) 1997-2012 for all cases of total (n = 3253) or partial (n = 2380) thyroidectomy. We then designed a propensity score matching model and compared total versus partial thyroidectomy based on surgical complications and outcomes.

RESULTS

In our cohort, the median age was 16 years and 79% were females. Those treated at a specialty pediatric hospital or pediatric unit in a general hospital comprised 73% of all patients. The most common indications for surgery were malignancy (46%) and goiter (42%). The most common complications were hypocalcemia and nerve injury with an unweighted incidence of 9% (n = 174) and 3% (n = 57) respectively. When compared to partial thyroidectomy, total thyroidectomy was associated with increased rates of postoperative complications. Additionally, the median length of stay was significantly higher for total thyroidectomy patients.

CONCLUSIONS

This is the largest analysis to date comparing outcomes for total versus partial thyroidectomy in the pediatric population. Surgeons should consider the increased rates of hypocalcemia and nerve injury complications when selecting total compared to partial thyroidectomy in children.

Clinico-statistical Considerations on Thyroid Cancer in the Youth

On a series of 220 patients with carcinoma of the thyroid, 17 (10 females and 7 males) were under the 24th year of age. In four cases the tumor was diagnosed between the 5th and the 14th year of age and in 13 cases between the 15th and the 24th year; there were 13 cases of papillary adenocarcinoma, 2 cases of follicular adenocarcinoma, and 2 cases of solid carcinoma. In 7 cases the tumor was preceded by the appearance of goiter; only one patient had been previously irradiated. The first clinical sign of disease was a thyroid nodule in 10 cases, metastases to cervical lymph nodes in 7 cases; in 3 of these last cases primary neoplasia of the thyroid remained clinically occult. Scanning with I181 was used in 13 cases for the diagnosis of thyroid cancer. Surgical and radiological therapies were associated in all cases; the enucleation of the tumor was performed in one case, emithyroidectomy in 7 cases, total thyroidectomy in 6 cases. Surgery was limited to dissection of the neck in 3 cases. In addition, thyroidectomy was associated to radical neck dissection in 9 cases with metastases. In all cases I181 was administered; in 7 cases it was associated to X-therapy and in 8 cases to telecobaltotherapy. One patient is alive 3 months after the beginning of the treatment, 6 patients from 1 to 3 years, 3 patients from 5 to 6 years, 2 patients after 8 years and 5 patients from 10 to 15 years.

Thyroid Cancer in Childhood

From 1956 to 1975 21 patients (13 females and 8 males) with thyroid cancer developed by age 14 have been observed at the Istituto Nazionale Tumori of Milan. Follicular adenocarcinoma was diagnosed in 4 cases and papillary adenocarcinoma in 17. Five patients (24%) had been given previous cervical irradiation for benign conditions. At admission lung metastases were evident in 2 patients (one affected by follicular and the other by papillary adenocarcinoma). All patients were submitted to surgical treatment, which in most cases consisted in total thyroidectomy plus elective lymph node dissection; serious postoperative complications were not observed. External irradiation was given to 4 patients, since surgery had not been radical. Radioiodine treatment was performed in the 2 patients with lung metastases: in the patient with follicular adenocarcinoma metastases disappeared after 131I treatment, whereas in the other one they still persist unmodified 10 years later. A local recurrence occurred in 3 cases and pulmonary metastases in one: all of them made an apparent recovery after surgical and/or radioiodine treatment. All patients are alive and, except one, without evidence of disease after a follow-up period from 14 months to 21 years. Although differences in evolution have been noted according to the histotype, the prognosis of thyroid cancer in childhood is good, evenif distant metastases are present.

Long-term outcome in 215 children and adolescents with papillary thyroid cancer treated during 1940 through 2008

BACKGROUND

Controversy exists regarding the aggressiveness of initial therapy in childhood papillary thyroid cancer (PTC). Few studies with long-term outcome exist and second primary malignancies have rarely been analyzed.

METHODS

We studied 215 PTC patients younger than 21 years old managed during 1940 through 2008. The patients were aged 3-20 year old (median age = 16 years); the median follow-up was 29 years. Recurrence and mortality details were taken from a computerized database.

RESULTS

Median primary tumor size was 2.2 cm. Six percent had distant metastases at presentation, 5% had incomplete tumor resection, 86% had nodes removed at initial surgery, and 78% had nodal metastases. After complete surgical resection, PTC recurred in 32% by 40 years. At 20 years, the recurrence rates at local, regional, and distant sites were 7, 21, and 5%, respectively. During 1940-1969, local and regional recurrence rates after unilateral lobectomy (UL) were significantly (P < 0.001) higher than after bilateral lobar resection (BLR). During 1950-2008 radioiodine remnant ablation (RRA) was administered within 18 months to 32%; it did not diminish the 25-year regional recurrence rate of 16% seen after BLR alone (P = 0.86). Only two fatal events from PTC occurred at 28 and 30 years, for a cause-specific mortality at 40 years of only 2%. All-causes mortality rates did not exceed expectation through 20 years, but from 30 through 50 years, the number of deaths was significantly (P < 0.001) higher than predicted. Fifteen of 22 deaths (68%) resulted from nonthyroid malignancy.

CONCLUSION

Survival from childhood PTC should be expected, but later death from nonthyroid malignancy is disconcerting. Seventy-three percent of those who died from nonthyroid malignancy had received postoperative therapeutic irradiation.

Differentiated Pediatric Thyroid Cancer: Correlates With Adult Disease, Controversies in Treatment

The biologic behavior of differentiated thyroid cancer can differ between adults and children, especially in those children younger than 10 years of age. Unlike adults, young children typically present with advanced disease at diagnosis. Despite this, children respond rapidly to therapy and have an excellent prognosis that is significantly better than that of their adult counterparts with advanced disease. In contradistinction to adults, children with thyroid cancer also have higher local and distant disease recurrences with progression-free survival of only 70% at 5 years, mandating life-long surveillance. Although thyroid cancer is the most common carcinoma in children, overall incidence is low, a factor that has prevented performance of a controlled, randomized, prospective study to determine the most efficacious treatment regimen in this age group. So, although extensively investigated, treatment of pediatric patients with differentiated thyroid cancer remains controversial. This article reviews the current controversies in the treatment of pediatric differentiated thyroid cancer, focusing on issues of optimal initial and subsequent therapy as well as that of long-term follow-up. Our approach to treatment is presented. In so doing, similarities and differences between adults and children with differentiated thyroid cancer as regards unique considerations in epidemiology, diagnosis, staging, treatment, therapy-related late effects, and disease surveillance are presented. The expanding use of and appropriate roles for thyrogen and fluorine-18-fluorodeoxyglucose positron emission tomography in disease evaluation and surveillance will be addressed.

Is chest x-ray or high-resolution computed tomography scan of the chest sufficient investigation to detect pulmonary metastasis in pediatric differentiated thyroid cancer?

We reviewed the clinical characteristics, pattern of disease at presentation, histopathologic subtype, treatment, course, and outcome of differentiated thyroid cancer (DTT) in children and adolescents presenting with pulmonary metastasis and tried to assess the effectiveness of routine chest x-ray and high-resolution computed tomography (CT) scan of the chest vis-à-vis 131I whole-body scan (WBS) in revealing pulmonary metastasis. In our series of 1754 patients, 122 (7%) were 20 years of age or younger, of whom 28 (23%) had pulmonary metastasis. Mean age was 13.9 +/- 4.4 years (F:M ratio = 12:16). All but 2 patients had undergone near-total thyroidectomy with some form of neck dissection. Histopathologic examination was papillary in 89% and follicular in 11% cases, with confirmed nodal metastasis in all. Twenty-one (75%) patients had normal chest x-ray. However, WBS revealed pulmonary metastasis in all cases. In 15 (54%) children pulmonary metastasis was detected by first postsurgery 2-3 mCi 131I WBS and in 4 (14%) patients by postablation 131I WBS. Seven cases (25%) and 2 cases were detected by first and second posttherapy 131I WBS, respectively. No statistically significant difference was observed in any of the demographic or clinical parameters in patients in whom pulmonary metastasis was detected by first postsurgical low-dose WBS versus those in whom metastasis was discovered at a later stage. When chest x-ray-positive children were compared to x-ray-negative children, a statistically significant difference was observed only for mean first dose, cumulative dose, and total number of doses of 131I, which were significantly higher in x-ray-positive children. Eighteen of 21 children who had normal chest x-ray also underwent CT scan of the chest. CT could detect micronodular pulmonary shadows in 5 (28%) children only. Complete radioiodine treatment and outcome information was available in 20 patients. Mean first dose and cumulative doses of administered 131I were 75.4 +/- 39.5 mCi and 352 +/- 263 mCi, respectively. After an average number of 3.3 doses of (131)I and mean duration of 33.2 +/- 28.5 months, pulmonary lesions disappeared in 14 (70%) patients and thyroglobulin (Tg) becoming undetectable. In 4 children, however, there was no radiologic or scintigraphical evidence of pulmonary metastasis, Tg was high and in 2 patients, disease was persisting clinically. To conclude, a large majority of pediatric patients with DTC have x-ray- and even high-resolution-negative pulmonary metastasis. However, these metastases are 131I avid, and thus are amenable to detection and treatment with radioiodine. Therefore, postsurgical evaluation with 131I is recommended in all children and adolescents.

Differentiated thyroid cancer in children and adolescents: clinical outcome and mortality after long-term follow-up

BACKGROUND

Children and adolescents with differentiated thyroid cancer (DTC) have a good prognosis and prolonged survival even when extensive regional disease or lung metastases are present at the diagnosis; very-long-term follow-up is needed to appreciate what, if any, impact the disease may exert on the ultimate outcome.

METHODS

We retrospectively reviewed the clinical course of 112 patients with DTC who registered at M. D. Anderson Cancer Center between 1944 and 1986, were younger than 20 years old at the time of diagnosis, and were followed for at least 10 years. Surgery alone or combined with radioactive iodine or radiotherapy was used for most cases.

RESULTS

At the time of most recent contact, 99 patients remained alive and 13 had died. The 99 patients had 25 +/- 0.9 years of available follow-up (mean +/- SEM) and were 41 +/- 0.9 years of age at time of last contact; one fourth had had recurrent disease at some point since diagnosis. Among the 13 patients who died, one died of complications from coexisting diabetes mellitus, and the cause of death was not clear in one other case. Two patients died of breast cancer 13 and 15 years after thyroid cancer diagnosis. In three cases, cause of death could be considered etiologically related to initial radiotherapy: one patient developed tracheal necrosis 26 years after diagnosis and died of upper airway complications, whereas another two patients developed sarcomas of the cervical region 22 and 29 years after thyroid cancer diagnosis. Lastly, six patients died of thyroid cancer 26 +/- 3.1 years after initial diagnosis (at age 40 +/- 2.1 years). Among these cases, one patient had invasive disease and lung metastases at diagnosis and died of progressive lung metastases after 36 years. The other five patients were initially seen with local/regional disease and developed lung and skeletal metastases after a 2- to 20-year disease-free interval.

CONCLUSIONS

Our findings support the clinical impression that children and adolescents with DTC live for many years regardless of apparent extent of disease at diagnosis or development of recurrence. Indeed, overall survival was 100% at 10 years even in patients with distant metastases. However, attention to these patients' clinical course beyond the first decade indicates that a small minority (5% to 7%) of patients eventually succumb to progressive disease and that a similar number develop possibly treatment-related lethal complications or second neoplasms. We suggest lifelong surveillance for all such patients.

Problems in diagnosis and management of goitre in childhood and adolescence

This study is a retrospective review of 17 patients aged 16 and under with a total of 18 goitres, who were investigated and treated at Bristol Children's Hospital and Bristol Royal Infirmary between 1967 and 1994. There were five neoplasms, comprising follicular adenoma (three) and papillary carcinoma (two). Other benign causes of goitre included nodular goitre (four), non-toxic hyperplasia (three) and chronic lymphocytic thyroiditis (three). The authors suggest some guidelines to help in the diagnosis and management of goitre in young patients, as a consequence of significant difficulties encountered in 12 of the 17 patients in this series.

Total thyroidectomy in the treatment of thyroid carcinoma in childhood

Between 1974 and 1993 ten girls and six boys aged 6-16 years underwent total thyroidectomy, with therapeutic selective neck dissection in six patients. All were treated after operation with radioactive iodine (131I) for ablation of thyroid tissue remnants. Papillary carcinoma occurred in ten patients, follicular carcinoma in two and medullary thyroid lesions in four. The patients were followed for a median of 11.5 (range 1-20) years with regular determinations of serum thyroglobulin levels and 131I whole-body scanning when indicated. Only one patient had a slight increase in thyroglobulin levels without evidence of disease on further screening. In children with medullary lesions the serum levels of basal and pentagastrin-stimulated calcitonin remained normal. Currently all patients are alive and without disease. Hypocalcaemia lasting for more than 1 year was observed in one patient. Recurrent nerves were not injured accidentally, but because of tumour invasion two of 32 recurrent nerves had to be sacrificed. This surgical approach is safe and well tolerated in children.

Papillary thyroid cancer with pulmonary metastases beginning in childhood: clinical course over three decades

We present a case of childhood papillary thyroid cancer with persistent but stable pulmonary metastases for over three decades in order to highlight the natural history and clinical features of this unusual disease entity. A nine-year-old girl had thyroidectomy and cervical lymph node dissection followed by neck irradiation for invasive papillary thyroid cancer. Diffuse pulmonary metastases were present at the time of diagnosis and were treated with radioactive iodine 10 and 30 years later; both the chest radiographs and the patient remained stable throughout. This case illustrates the potential indolence of thyroid cancer when it presents during childhood.

Pediatric thyroid cancer after the Chernobyl disaster. Pathomorphologic study of 84 cases (1991-1992) from the Republic of Belarus

BACKGROUND

During the initial period after the Chernobyl accident, large amounts of radioactive iodine were released in fallout, resulting in serious exposure to the thyroid gland in the residents of areas around the nuclear power station. Beginning in 1990, a definite increase in the incidence of thyroid cancer was noted in children of the Republic of Belarus.

METHODS

Morphologic and clinical features of 84 cases of post-Chernobyl thyroid carcinoma in Belarussian children from 5 to 14 years of age are reported. The latent period for tumor development was 4-6 years, with a mean of 5.8 years.

RESULTS

Papillary carcinoma was found in 83 patients and medullary carcinoma in one. Besides typical papillary carcinoma (14%), solid (34%), follicular (33%), mixed (10%), and diffuse sclerosing (9%) variants were observed. The follow-up period ranged from 8 months to 2.5 years. One patient died, local recurrence developed in 2, and cervical lymph node metastases developed in 10. To date, the incidence of local recurrence or metastatic disease after surgery was significantly higher in patients 5-8 years of age and in residents of areas nearest to the Chernobyl station.

CONCLUSIONS

Post-Chernobyl pediatric thyroid carcinoma is characterized by a short latency, a higher proportion of tumors arising in young children, and an almost equal sex ratio. Microscopically, these tumors were usually aggressive, often demonstrating intraglandular tumor dissemination (92%), thyroid capsular and adjacent soft tissue invasion (89%), and cervical lymph node metastases (88%). Papillary carcinoma was diagnosed in 99% of cases, with an unusually high frequency of solid growth patterns. Morphologic changes in nonneoplastic thyroid tissue were present in 90% of the glands, and the most specific findings were vascular changes and perifollicular fibrosis.

Pulmonary metastases in children and young adults with differentiated thyroid cancer

BACKGROUND

The prognostic significance and optimal care of children with differentiated thyroid cancer and pulmonary metastases are not well established.

METHODS

Of 209 patients younger than 25 years of age who were treated at University of Texas M. D. Anderson Cancer Center between 1960 and 1990 and for whom there was sufficient information, 19 (9%) had pulmonary metastases at presentation.

RESULTS

All of these patients had regional lymphadenopathy at the time of diagnosis. All but two had intense, diffuse radioiodine uptake in the lungs; there were two false-negative scans immediately after surgical procedure caused by competing thyroid residual. The chest radiograph (CXR) was normal in 8 of 17 (42%) patients with abnormal radioiodine scans. After therapy with radioiodine (100-499 mCi), CXR appeared normal in 7 of 9 patients with initial abnormal radiographs (within 6-75 months). Radioiodine uptake by the lungs normalized in 3 of 8 patients with initially normal radiographs, and in 3 of 9 patients with initially abnormal radiographs. There have been no deaths in these 19 patients.

CONCLUSION

Pulmonary metastases are not uncommon in children and young adults with differentiated thyroid cancer, especially those who have regional lymphadenopathy. The lung metastases almost always concentrate radioiodine diffusely and may be associated with a normal CXR in almost half of the patients. Pulmonary metastases may be overlooked unless near total thyroidectomy is followed by total body radioiodine scan (TBS) in all children and young adults who have regional lymphadenopathy of the neck.

Thyroid Carcinoma in Children and Adolescents

Carcinoma of the thyroid gland, although fairly common in young adults, is uncommon in the first two decades of life. Because therapy is controversial, it is important to study a relatively large group of patients treated in a single department. This report records the findings and responses to treatment in 40 cases of thyroid gland carcinoma in children and adolescents treated from 1953 to 1982.

Thyroid cancer in childhood

Thyroid cancer in childhood is a relatively rare condition. Often it shows biological characteristics different from those seen in adults. Based upon 10 cases in our clinic and 57 cases collected from the Japanese literatures, clinical features, pathology, treatment and prognosis of thyroid cancer in childhood are discussed. Pathogenesis is most likely to be related to hormonal changes during adolescence and previous radiation of the neck region. Cervical lymph nodes swelling was the chief complaint in 84.6 per cent of the cases. On the other hand, pulmonary metastases were recognized in the early stages in 33.5 per cent of the cases. Radical excision of the tumor with modified radical neck dissection is the treatment most frequently employed even in the presence of lung metastases. However, hypoparathyroidism and recurrent nerve injuries should be avoided at all cost in view of long life expectancy and the difficulty in treating them satisfactorily. Prognosis could be as good for children as it is for adults except in cases with early lung metastases.

An unusual thyroid tumor in a child

Malignant neoplasms of the thyroid gland are quite rare in children. Winship, in his classic article, could find only 562 cases in the literature. The histopathological patterns resemble those of the adult tumors. Despite early cervical metastasis, the prognosis in general is favorable, with many long-term survivals. Prior exposure to radiation of the head and neck is a definite pre-disposing factor. Teratomas of the neck are a medical curiosity--less than 100 cases are described in the literature. The vast majority of these are found during the neonatal period, and are benign histologically. These are usually large, cystic, bulky masses which produce mechanical obstruction of the upper airway and digestive tract. Only one of these tumors, described by Pupovac in 1896, has been considered malignant. A six-year-old child was examined with a right thyroid mass of three months' duration. The thyroid scan showed a "cold nodule." At surgery, a well-encapsulated mass was found. The pathology showed a predominance of malignant spindle cells, with areas of papillary carcinoma; however, there were well-defined mucous glands present in the tumor. Clinically the child has remained well and asymptomatic. The slides have been extensively reviewed. To my knowledge no such tumor has been previously described. The tumor is considered to be a malignant thyroid tumor growing out of teratomatous tissue.

Total thyroidectomy for occult familial medullary carcinoma of the thyroid in children

Experience with 17 children in one kindred with familial medullary carcinoma of the thyroid and pheochromocytoma has demonstrated the utility and validity of periodic provocative testing by calcium infusion or pentagastrin injection in the identification of children with early medullary carcinoma of the thyroid or its premalignant precursor, C-cell hyperplasia. In these 17 patients with two consecutive elevations of calcitonin levels greater than 0.55 ng/ml after stimulation all but one have had MTC or CCH at operation. Total thyroidectomy has been well tolerated and can be performed with an acceptably low incidence of complications in this group of patients.

Thyroid cancer in young patients in Great Britain

Recent collective experience with thyroid cancer in children in Britain is reported. Fifteen out of 16 patients with papillary carcinoma treated in the years 1962–7 are still living at least 5–10 years later; the sixteenth patient died of an unrelated cause. Two patients with follicular carcinoma also survived. Seven deaths between 1957 and 1970 were due to anaplastic or medullary carcinomas and 1 death was caused by a papillary carcinoma.

These data emphasize that in the treatment of papillary carcinoma we should take account of its prolonged natural history. Radical operations which have serious associated morbidity do not appear to be indicated.