Pediatric thyroid cancer

A Unique Case of Bilateral Hürthle Cell Adenoma in an Adolescent

BACKGROUND

Hürthle cell (HC) neoplasms are rare among pediatric thyroid cancers. HC adenomas (HCA) are typically benign and localized unilaterally without recurrence, and they are thus treated by hemithyroidectomy. HC carcinomas (HCC) can be bilateral and are more aggressive, necessitating total thyroidectomy. Diagnosis relies upon surgical histopathology demonstrating invasion for classification as HCC or lack of invasion in HCA, since fine needle aspiration fails to differentiate between the two.

METHODS

We report a case of a 14-year-old adolescent female with bilateral HCA. She had an initial left hemithyroidectomy for a large nodule measuring 2 × 1.5 × 1.2 cm3 in the left lobe, while smaller subcentimeter nodules remained under surveillance in the right. One year later, a nodule in the right lobe doubled in size, necessitating a right hemithyroidectomy which also revealed HCA.

CONCLUSION

To our knowledge, this is the first reported case of bilateral HCA in pediatrics. It highlights the importance of close surveillance of persistent small nodules, even in patients with previously documented benign lesions such as HCA, which are typically thought to be unilateral and localized. Both HCA and HCC remain unpredictable in behavior, and treatment of HCA should be individualized.

Lymphocytic infiltration in pediatric thyroid carcinomas

Lymphocytic thyroiditis has been associated with an increase in the incidence of thyroid papillary carcinoma in some reports, mostly series of both adults and children. Relatively little is written about thyroiditis and follicular carcinomas. We have seen several cases of pediatric follicular thyroid carcinomas, that had an associated lymphocytic infiltrate, which led us to examine all primary malignant thyroid neoplasms in our surgical files from 1984 through 2000 to examine this relationship. We also investigated the nature of the lymphocytic infiltrate with routine immunohistochemistry. Ten patients (five male, five female, ages 4.5-21 years of age) had a thyroid carcinoma resection, six (three males and three females) with papillary carcinoma and four patients (two males and two females) with low-grade follicular carcinoma. Seven samples (one male had two cases with tumor) from patients who had a papillary carcinoma resection with tissue blocks available were identified (one patient had slides but no blocks), as were all four patients with a follicular carcinoma. The thyroid of all patients with a follicular carcinoma contained a lymphocytic infiltrate; only four of the seven papillary carcinoma samples had an associated lymphoid infiltrate. In all cases with a lymphoid infiltrate, the infiltrate was present in both lobes (both adjacent and separate from the tumor). B lymphocytes were present in the lymphoid infiltrate of three of four patients with follicular carcinomas and in 1 of 3 cases of papillary carcinomas. T cells were dispersed throughout all the tumors with lymphoid infiltrates. We conclude that pediatric follicular carcinomas have an associated lymphocytic infiltrate in the tumor and/or adjacent thyroid, more commonly than papillary carcinomas.

Evaluation and management of a solitary thyroid nodule in a child

Although an uncommon clinical entity, a pediatric patient with a solitary thyroid nodule requires a thorough assessment because of the increased incidence of thyroid carcinoma in this population. In the future, one may expect the widespread clinical use of genetic markers in identifying children, who are at risk for, or who have developed, thyroid carcinomas, with the hopes that these molecular markers will lead to the prevention, or earlier detection and cure, of these malignancies.

Etiology and significance of the optically clear nucleus

Papillary thyroid carcinoma (PTC) is diagnosed in both cytology and surgical pathology specimens on the basis of distinct nuclear morphology, characterized by nuclear elongation, chromatin clearing, intranuclear grooves, and inclusions. Although these nuclear features are specific to papillary carcinoma, they can be mimicked in some benign conditions. The majority of PTC cases do not pose diagnostic problems. However, a distinct subset of cases has generated controversy among experts. These cases are follicular patterned tumors that show minimal nuclear changes in PTC. Several investigators have explored the role of immunohistochemical markers in the histologic diagnosis of PTC. Somatic rearrangements of the RET protooncogene are the most frequent genetic abnormality found in PTC. The frequency of these rearrangements has varied according to the geographic region, radiation exposure, and methodologies used and histologic variant of PTC. Recent studies have suggested that RET/PTC may be the cause of this specific nuclear change in PTC; however, the role of RET/PTC in tumor progression still needs to be defined.

Metastatic pure papillary thyroid carcinoma presenting as a toxic hot nodule

In the majority of cases, carcinoma of the thyroid presents as a cold nodule by radioiodine and Tc-99m sodium pertechnetate scintigraphy. Whereas the presence of a hot nodule usually implies a benign entity, it does not provide complete assurance against thyroid malignancy. Presented is a rare case of metastatic pure papillary thyroid carcinoma appearing as a hot nodule on Tc-99m sodium pertechnetate and I-123 sodium iodide scintigraphy. The implications of such a case, its management, and review of the pertinent literature are discussed.

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.

Hürthle cell carcinoma in an autonomous thyroid nodule in an adolescent

A 16-year-old girl presented with a palpable thyroid nodule which was found to be functioning autonomously by radioiodine (123I) scintigraphy. After needle biopsy proved non-diagnostic, surgical excision showed the nodule to be Hürthle cell carcinoma. Functional thyroid nodules are rarely malignant, thyroid carcinoma is rare in childhood, and Hürthle cell carcinoma is a rare thyroid neoplasm, so the presence of these three rare conditions in one patient makes it a very unusual case.

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.

Pathomorphological findings in thyroid cancers of children from the Republic of Belarus: a study of 86 cases occurring between 1986 ('post-Chernobyl') and 1991

Recently, an impressive increase in malignant thyroid tumours has been observed among children less than 15 years of age living in the Republic of Belarus at the time of the nuclear accident of Chernobyl in 1986. More than half of these patients lived in the region of Gomel, nearest to Chernobyl. Because of the very short time interval between the accident and the tumour occurrence an independent review of the available histopathological material was done. Out of 101 cases diagnosed as thyroid cancers, we reviewed slides of 93 cases and agreed the diagnosis of malignancy in 92.5%. Of these tumours 96.5% were papillary carcinomas, 61.5% were moderately or poorly differentiated. Extrathyroidal extension was observed in 60.5%, regional lymph node metastases in 74% and distant metastases in 7%. One of the patients died from lung metastases. Our results confirm that the neoplasms increasingly diagnosed between 1986 and 1991 among children of this region are thyroid carcinomas. In addition, we correlate several histopathological findings with sex and age of the patients and other parameters, and compare the results with data from other studies.