[Comparative clinical and morphological analysis of technogenic and cryptogenic papillary thyroid carcinoma in children and adolescents].

OBJECTIVE: To make a comparative retrospective clinical and morphological analysis of cases of post-Chernobyl (technogenic) and sporadic (cryptogenic) papillary thyroid carcinoma (PTC) in children and adolescents in the Republic of Belarus. MATERIAL AND METHODS: Nine hundred and thirty-six patients aged less than 19 years, operated on in 1990-2005, when cancer incidence in this age group was directly related to the consequences of the Chernobyl accident (technogenic carcinoma) were examined. A comparison group included their 140 peers who were born after March 1987 and treated in 2005-2010 for PTC (cryptogenic carcinoma). The Kruskal-Wallis test was used to compare quantitative variables; the Fisher, Pearson, and Fisher-Freeman-Halton tests were employed to compare categorical variables. All calculations were made using the R package version 2.15.0. The results were considered to be statistically significant at p<0.05. RESULTS: Comparison of cases of cryptogenic carcinoma and those of technogenic carcinomas diagnosed in 1990-1995 and 1996-2001 revealed substantial differences in the clinical and morphological patterns of the disease. In both mentioned periods, the patients with technogenic PTC were younger than those with cryptogenic PTC (p<0.0001 and p=0.0014, respectively). The proportion of male patients in the technogenic carcinoma group was much higher than that in the cryptogenic carcinoma one (p=0.0006 and p=0.0031). The patients with technogenic carcinoma were also more frequently observed to have infiltrative tumor growth (p=0.0003 and p=0.0169) and lung metastastic involvement (p=0.0001 and p=0.0008). What is more, the architectonics of technogenic versus cryptogenic carcinoma more often contained a solid component (p<0.0001 and p<0.0001), marked intratumoral fibrosis (p=0.0008 and p=0.0266), mononuclear infiltration (p<0.0001 and p<0.0001), and no baseline abnormality (p<0.0001 and p<0.0001). CONCLUSION: In spite of its age similarity, technogenic carcinoma proved to be more clinically aggressive than cryptogenic carcinoma: the extent of organ invasion and the infiltrative growth of carcinoma were more frequently observed.

Congenital cervical immature teratoma arising in the left lobe of the thyroid gland.

We report on a fetal autopsy case in which a congenital cervical immature teratoma was diagnosed. A 24-year-old Japanese woman had carried a male fetus that was aborted because of a cervical tumor at 20 weeks 5 days of gestation. The cervical tumor weighed 93 g and measured 7.5x5.5x5 cm. The soft tumor was encapsulated by a fibrous layer, was solid with small cysts on the cut surface, and showed a brain-like appearance. The tumor was composed of neoplastic cells derived from the three germ cell layers: ectoderm, mesoderm, and endoderm. The cells showed both immature and mature features. Small areas of thyroid tissue were detected in the cervical tumor. The left lobe of the thyroid gland was not observed, but the right lobe of the thyroid gland was present laterally between the trachea and the esophagus. Therefore, we concluded that the cervical tumor had arisen in the left lobe of the thyroid gland rather than from the soft tissue of the neck.

Early cellular abnormalities induced by RET/PTC1 oncogene in thyroid-targeted transgenic mice.

The RET/PTC1 oncogene, a rearranged form of the RET proto-oncogene, has been reported to be associated with human papillary thyroid carcinomas. We have shown that targeted expression of RET/PTC1 in the thyroid gland leads to the development of thyroid carcinomas in transgenic mice with histologic and cytologic similarities to human papillary thyroid carcinoma. To further investigate how RET/PTC1 expression contributes to the pathogenesis of papillary thyroid tumor, the time of tumor onset and the early phenotypic consequences of RET/PTC1 expression in thyrocytes were determined. All high copy transgenic mice developed bilateral thyroid tumors as early as 4 days of age. At embryological days 16-18, increased proliferation rate, distorted thyroid follicle formation and reduced radioiodide concentrating activity were identified in transgenic embryos. The reduced radioiodide concentrating activity was attributed to decreased expression of the sodium-iodide symporter. Our study showed that RET/PTC1 not only increased proliferation of thyrocytes, it also altered morphogenesis and differentiation. These findings provide a model for the role of RET/PTC1 in the formation of abnormal follicles with reduced iodide uptake ability observed in human papillary thyroid carcinoma.

The C-cells: current concepts on normal histology and hyperplasia.

We describe the current concepts on the embryology, normal morphology and immunohistochemistry of a minor cell population of the thyroid, the C-cells. We also try to make delineation between the normal number of the C-cells and C-cell hyperplasia. The two types of C-cell hyperplasia, physiologic and neoplastic are defined and characterized from morphologic and genetic point of view. Their relation with thyroid pathology, especially with medullary thyroid carcinoma is discussed.

Poorly differentiated thyroid carcinomas with primordial cell component. A group of aggressive lesions sharing insular, trabecular, and solid patterns.

Poorly differentiated carcinomas of the thyroid share insular, trabecular, and solid histological patterns that are different from those of papillary, follicular, medullary, and anaplastic varieties. We have collected 63 cases of poorly differentiated thyroid carcinomas. Thirty-one tumors (Group A) corresponded to the so-called insular carcinomas, and 32 tumors (Group B) had predominant trabecular and solid or focally follicular patterns in the presence of a minor insular component. The cells characterizing these lesions were relatively small and globoid, with uniform nuclei and intracytoplasmic deposits of thyroglobulin. They were in every respect similar to primordial cells present in the early stages of fetal thyroid development. None of the tumors proved fatal within 6 months, and most responded to radioiodine therapy. Although no differences in survival between the two groups were found, a significantly (p < 0.01) higher percentage of recurrences or distant metastases was observed with Group A tumors. The term primordial cell carcinoma appears appropriate for this type of tumor, which displays characteristic histocytological features and production of thyroglobulin. Clinically, these tumors are aggressive but generally show a slow course and good response to radioiodine therapy.

Embriología y cáncer del tiroides / Embryology and thyroid cancer

La embriología tiene vínculos, con frecuencia olvidados,con los procesos malignos del tiroides. La aplasia o hipoplasia tiroideas determinan hallazgos gammagráficos de la glándula o ectopías tiroideas en su variedad de tiroides lateral plantean el problema "lesión cáncer", que algunos casos puede no ser cierto. Incluso el tejido tiroideo dentro de un ganglio cervical no implica necesariamente el diagnóstico de cáncer. Se discute la posible relación de los "nidos celulares sólidos" con el carcinoma medular, y otros aspectos de interes

Embriología y cáncer del tiroides / Embryology and thyroid cancer

La embriología tiene vínculos, con frecuencia olvidados,con los procesos malignos del tiroides. La aplasia o hipoplasia tiroideas determinan hallazgos gammagráficos de la glándula o ectopías tiroideas en su variedad de tiroides lateral plantean el problema "lesión cáncer", que algunos casos puede no ser cierto. Incluso el tejido tiroideo dentro de un ganglio cervical no implica necesariamente el diagnóstico de cáncer. Se discute la posible relación de los "nidos celulares sólidos" con el carcinoma medular, y otros aspectos de interes

Cervical teratoma in a fetus and an adult. Two case reports and review of literature.

Two cases of cervical teratoma in a 30-weeks fetus and a 26-year-old female have been presented. In the former case a large mass entirely occupied the anterior neck but showed no invasive or metastatic lesions, and in the other case a mass containing multiple cysts was situated in the right lower pole of the thyroid gland. Histologically, both tumors were composed of the elements derived from three germ layers including various epithelial components, cartilage, muscle, and adipose tissue. In addition to these predominantly mature elements, there were some elements showing primitive immature structure in the former case. Positive immunohistochemical staining for thyroglobulin displayed only in the former case and was observed in the compressed thyroid follicles located in the fibrous capsule and several small foci of primitive glandular structure which was an element of the tumor.

Papillary adenocarcinoma of thyroglossal duct remnant.

The authors report the case of a 52-year-old woman who presented with an anterior neck mass, which was excised and diagnosed at pathological examination as papillary adenocarcinoma arising in a thyroglossal duct remnant. Echography and computed axial tomography of the neck were utilized to exclude the presence of thyroid gland neoplasia. The patient was discharged on suppressive thyroid therapy, and after follow-up examination at two years was found to be free of recurrent neoplastic lesion.

Dysontogenetic neoplasms of the thyroid gland in infancy: two case reports.

Two rare cases of benign dysontogenetic neoplasms of the thyroid gland in pediatric age are presented, which were observed at the E.N.T. department of the Bambino Gesù Hospital of Rome, and successfully operated. The first case turned out to be a dysembryoma, classified as monodermic because of its origin from derivatives of only one germinal layer, the entoderm. The second case, a teratoma, presented a high seric concentration of AFP as the consequence of the synthetic activity of the share of embryonal epatic tissue present in the neoformation. Criteria to distinguish thyroid from cervical teratomata and to classify the different types of dysontogenetic neoplasms are discussed. The usual clinical and pathological manifestations of teratomas of the neck in infancy are mentioned. The necessity of a prompt surgical removal and of pre- and postoperative thyroid function studies is mentioned.

[2 cases of thyroid lipoma]. / Deux cas de thyro-lipome.

Report of two cases of thyro-lipoma, a rare variety of adenoma containing fat cells. Only five cases have been reported. Embryogenic or metaplasic origin of the adipose tissue is discussed.

Neurocrest and colonic tumors: new clinical syndrome. Report of three cases.

This report describes three patients with both multiple intestinal polyps and tumors of neural crest origin. This combination of findings may represent a new clinical syndrome. The embryologic relationships between tumors derived from endoderm and tumors derived from neurocrest are described. An inherent defect in tissue proliferation or repair is postulated to explain the abnormal growth in these two different cell lines.

[Value of immunohistochemistry in the study of medullary cancer of the thyroid. Implications of the results for the concept of the APUD system and of apudomas]. / Intérêt de l'immunohistochimie dans l'étude du cancer médullaire de la thyroïde. Implication des résultats pour le concept de système "A.P.U.D." et d'"apudome".

Immunohistochemical studies in medullary thyroid carcinoma demonstrate the presence of C cells secreting calcitonin but also of other cells secreting other peptides or proteins. These different cells exist in the tumor as well as in metastases. These results and other reported in the literature suggest a common ultimobranchial and endodermal origin for these cells.

[Thyroid dysembryoma. Report of a case in an adult (author's transl)]. / Les dysembryomes thyroïdiens. A propos d'une observation chez l'adulte.

One case of dysembryoma of the thyroid gland is reported. 115 cases of that rare disease have been published; the tumor is particularly rare in adult (14 cases). Salient features are reviewed, mostly complications and malignant degeneration. Surgical removal is the only treatment and also the only mean to have histological diagnosis.

[Primary malignant teratoma of the thyroid. Report of one case and review of the literature (author's transl)]. / Tératome malin primitif de la thyroïde. Rapport d'un cas et revue de littérature.

Malignant teratomas of the thyroid in the adult are rare. A personal case is presented. It brings the total number of cases found in the literature to nine, and illustrates the terrible prognosis of these tumours regardless of the treatment used (extensive surgery, radiotherapy, chemotherapy). Teratomas in the adult thus differ from those in the newborn and child. The latter are much more common and recurrences virtually non-existent. The histogenesis of these tumour is discussed. It may dysgenetic heterotypism, but no definite conclusions may be offered.

[Malignant teratomas of the thyroid body. Apropos of 2 cases]. / Les tératomes malins du corps thyroïde. A propos de deux observations.

The literature was reviewed in the light of two cases of malignant teratoma of the thyroid in young women. It would seem that the histological diagnosis is easy, with frequent predominance of neuroid tissue at varying levels of maturity. By contrast, the histogenesis remains in the area of hypothesis: germinal theory and embryonic theory of teratomas, or heterotopism of cells of the neural crest, taken up by thyroid C cells.