Localization of a susceptibility gene for familial nonmedullary thyroid carcinoma to chromosome 2q21.

The familial form of nonmedullary thyroid carcinoma (NMTC) is a complex genetic disorder characterized by multifocal neoplasia and a higher degree of aggressiveness than its sporadic counterpart. In a large Tasmanian pedigree (Tas1) with recurrence of papillary thyroid carcinoma (PTC), the most common form of NMTC, an extensive genomewide scan revealed a common haplotype on chromosome 2q21 in seven of the eight patients with PTC. To verify the significance of the 2q21 locus, we performed linkage analysis in an independent sample set of 80 pedigrees, yielding a multipoint heterogeneity LOD score (HLOD) of 3.07 (alpha=0.42), nonparametric linkage (NPL) 3.19, (P=.001) at marker D2S2271. Stratification based on the presence of at least one case of the follicular variant of PTC, the phenotype observed in the Tas1 family, identified 17 such pedigrees, yielding a maximal HLOD score of 4.17 (alpha=0.80) and NPL=4.99 (P=.00002) at markers AFMa272zg9 and D2S2271, respectively. These results indicate the existence of a susceptibility locus for familial NMTC on chromosome 2q21.

Mono- and plurihormonal thyrotropic pituitary adenomas: pathological, hormonal and clinical studies in 12 patients.

In a series of 12 patients (eight women and four men, aged between 20 and 62 years), operated on for a pituitary adenoma shown to be thyrotropic by immunocytochemistry, we performed a retrospective and comparative analysis of clinical and biological data, tumor studies including immunocytochemistry with double labeling, and proliferation marker (proliferative cell nuclear antigen (PCNA) and Ki-67) detection, electron microscopy and culture. Our study leads us to confirm that thyrotropic tumors are rare (12 of 1174 pituitary adenomas: 1%). The main points arising were that: (1) high or normal plasma TSH associated with an increase in plasma alpha-subunit and high thyroid hormone levels is the best criterion for diagnosis; (2) the failure of TSH to respond to TRH or Werner's test is not a reliable criterion for diagnosis; (3) thyrotropic adenomas may be 'silent', without clinical signs of hyperthyroidism and with only slight increase in TSH, tri-iodothyronine and thyroxine concentrations; (4) mitoses and nuclear atypies are frequently detected in large tumors, which are invasive in more than 50% of cases - the first analysis of two proliferation markers (PCNA and Ki-67) bears out the relative aggressiveness of thyrotropic adenomas; (5) thyrotropic adenomas are frequently plurihormonal. Immunocytochemical double labeling, complemented by in vitro study, showed that thyrotropic tumor cells sometimes can or sometimes cannot cosecrete TSH, GH or prolactin. The pathological identification of monohormonal and plurihormonal adenomas seems to be supported by clinical and biological differences.

[Papillary microcarcinoma of the thyroid. 179 cases reported since 1973]. / Le micro-carcinome papillaire du corps thyroïde. 179 cas observés depuis 1973.

OBJECTIVES: Defined as a tumor measuring < or = 1 cm, the prognosis and treatment of occult papillary thyroid carcinoma has been the topic of some controversy. The aim of this study was to report experience with a series of 179 cases observed since 1973. PATIENTS AND METHODS: Occult papillary thyroid carcinoma was discovered in 179 patients aged 12 to 81 years (151 women and 28 men) at cervicotomy prescribed for Graves' disease (n = 9), toxic adenoma (n = 16), isolated nodule (n = 71), multinodular goiter (n = 74) or cervical node enlargement (n = 9). The surgical procedures were lobo-isthmectomy (n = 79), subtotal thyroidectomy (n = 74), or total thyroidectomy (n = 26) with node dissection in case of enlargement. Thyroxin was prescribed in all cases and annual follow-up was programmed. Five patients were lost to follow-up. RESULTS: Two cervical recurrences were observed warranting reoperation. None of the patients died from cancer-related causes. CONCLUSION: Minute papillary carcinomas of the thyroid are frequently discovered, but prognosis is generally excellent. Systematic total thyroidectomy and node dissection are not warranted. Only those lesions with an extrathyroid extension, associated node enlargement or inaugural metastasis require wide resection. These results are in agreement with a critical analysis of data reported in the literature demonstrating the exceptional nature, and in half of the cases, cure of metastatic occult papillary thyroid carcinoma.

[Treatment of differentiated thyroid cancers of nodular type]. / Traitement des cancers thyroïdiens différenciés à forme nodulaire.

Papillary and follicular carcinomas are the most frequent thyroid cancers. The choice of the treatment is dependent on the prognostic scoring systems. A good prognosis is linked to the small size of the nodule (especially) microcarcinoma) the age of the patient (less than 40), the lack of extra-thyroid (for papillary cancer) or extra capsular (for follicular carcinoma) extension. Total thyroidectomy decreases the number of recurrences but does not modify the mortality. The risk of laryngeal nerve palsy and hypoparathyroidism is not negligible. Lobo-isthmectomy thus can be used in the low risk tumors. Radioactive iodine administration is rational after total thyroidectomy but its efficacy is questioned. Thyroxine treatment is always prescribed. Taking into account the risk of osteopenia and cardiovascular disturbances induced by iatrogenic thyrotoxicosis, the desirable serum TSH level is debated.