Thyroid and parathyroid tumours in patients submitted to X-ray scalp epilation during the tinea capitis eradication campaign in the North of Portugal (1950-1963).

Tinea capitis attained epidemical proportions in the fifth and sixth decades in Portugal, as in other countries. Before starting the utilization of griseofulvin in 1959, the best approach to treat tinea capitis infection was X-ray scalp epilation combined with topical antimycotic ointments. A long-term side effect of this therapy is thyroid disease, namely thyroid cancer; data on parathyroid lesions (hyperplasia, adenoma and carcinoma) are scarce. We observed clinically 1,375 individuals irradiated in childhood for tinea capitis treatment in the North of Portugal with the main purpose of evaluating thyroid and parathyroid tumours as possible sequelae of the irradiation treatment. For each individual, a cervical ultrasound and a serum calcium measurement were proposed. Fine needle aspiration cytology was suggested whenever ultrasound thyroid nodules presented suspicious features. We observed a 54 % frequency of thyroid nodules and a 2.8 % frequency of thyroid carcinoma (38/1,375). Nineteen of the 38 (50 %) carcinomas were diagnosed by us, whereas the remaining 19 carcinomas had been diagnosed and treated prior to our observation. The carcinomas were significantly more frequent in women than in men. Benign excised lesions were also significantly more frequent in women and in patients irradiated at younger ages. Seven women, considered asymptomatic until our clinical observation, had laboratory signs of hyperparathyroidism. The data we have obtained, namely high thyroid cancer frequency, corroborate previous data from childhood irradiated cohorts and highlight the need for the close follow-up of these populations in order to identify and treat early undiagnosed head and neck lesions. No evidence of increased parathyroid disease was found in this cohort of head and neck X-irradiated patients.

Mitochondrial D310 D-Loop instability and histological subtypes in radiation-induced cutaneous basal cell carcinomas.

BACKGROUND: Basal cell carcinoma (BCC) is the most frequent skin cancer. An elevated prevalence of BCC has been associated with radiation, namely after the Tinea capitis epilation treatment, being these tumors described as more aggressive. Mitochondrial DNA (mtDNA) mutations have been reported in many human tumors, but their occurrence in BCC is poorly documented. OBJECTIVE: The purpose of this work was to evaluate BCC histological subtypes in individuals subjected to X-ray epilation for Tinea capitis treatment when compared to non-irradiated patients. Moreover we also wanted to evaluate mitochondrial D-Loop instability in both groups of BCCs in order to compare the frequency of D-Loop mutations in post-irradiation BCC versus sporadic BCC. METHODS: 228 histological specimens corresponding to BCCs from 75 irradiated patients and 60 non-irradiated patients were re-evaluated for histological subtype. Subsequently, we sequenced the D-Loop 310 repeat in blood, oral mucosa, tumor lesions and, whenever available, non-tumoral adjacent tissue from these patients. RESULTS: The infiltrative subtype of BCC, considered to be more aggressive, was significantly more frequent in irradiated patients. BCC D-Loop D310 mutation rate was significantly higher in irradiated BCCs than in the non-irradiated ones. Moreover, it was associated with a higher irradiation dose. The presence of mtDNA heteroplasmy in patients' blood was associated with a higher mutation rate in the BCCs suggesting that a more unstable genotype could predispose to mtDNA somatic mutation. CONCLUSIONS: Our results suggest that radiation-induced BCCs may be considered to be more aggressive tumors. Further studies are needed to clarify the role of mtDNA D-Loop mutations in tumors from irradiated patients.

Genetic alterations in thyroid tumors from patients irradiated in childhood for tinea capitis treatment.

OBJECTIVE: Exposure to ionizing radiation at young age is the strongest risk factor for the occurrence of papillary thyroid carcinoma (PTC). RET/PTC rearrangements are the most frequent genetic alterations associated with radiation-induced PTC, whereas BRAF and RAS mutations and PAX8-PPARG rearrangement have been associated with sporadic PTC. We decided to search for such genetic alterations in PTCs of patients subjected in childhood to scalp irradiation. DESIGN: We studied 67 thyroid tumors from 49 individuals irradiated in childhood for tinea capitis scalp epilation: 36 malignant (12 cases of conventional PTC (cPTC), two cPTC metastases, 20 cases of follicular variant PTC (FVPTC), one oncocytic variant of PTC and one follicular carcinoma) and 31 follicular thyroid adenomas. METHODS: The lesions were screened for the BRAF(V600E) and NRAS mutations and for RET/PTC and PAX8-PPARG rearrangements. RESULTS: BRAF(V600E) mutation was detected in seven of 14 (50%) cPTC and two of 20 FVPTC (10%) (P=0.019). NRAS mutation was present in one case of FVPTC (5%). RET/PTC1 rearrangement was found, by RT-PCR, in one of 17 cases (5.9%) and by fluorescence in situ hybridization in two of six cases (33%). PAX8-PPARG rearrangement was not detected in any carcinoma. None of the follicular adenomas presented any of the aforementioned genetic alterations. CONCLUSIONS: The prevalence of BRAF(V600E) mutation in our series is the highest reported in series of PTCs arising in radiation-exposed individuals. The prevalence of RET/PTC1 rearrangement fits with the values recently described in a similar setting.

MEN1 intragenic deletions may represent the most prevalent somatic event in sporadic primary hyperparathyroidism.

OBJECTIVE: Primary hyperparathyroidism (pHPT) is characterised by an inappropriate over production of parathyroid hormone and it is the most frequent pathological condition of the parathyroid glands. A minority of the cases belong to familial forms, but most of them are sporadic. The genetic alterations underlying the sporadic forms of pHPT remain poorly understood. The main goal of our study is to perform the molecular characterisation of a series of sporadic pHPT cases. DESIGN AND METHODS: We have studied matched blood and tumour from 24 patients with pHPT, who went to a medical appointment in Hospital Pedro Hispano. Informed consent was obtained from all individuals. The MEN1, RET and CDKN1B molecular study was carried out in the germline DNA by PCR/SSCP and direct sequencing. Parathyroid tumours were further analysed by the same methods for MEN1, CDKN1B and CTNNB1 genetic alterations. The multiplex ligation-dependent probe amplification technique enabled the evaluation of MEN1 gene deletions. Protein expression for menin, cyclin D1, parafibromin, p27(Kip1), ß-catenin and Ki-67 was conducted by immunohistochemistry. RESULTS: The study of parathyroid tumours detected two somatic MEN1 mutations (c.249_252delGTCT and c.115_163del49bp) and revealed the presence of MEN1 intragenic deletions in 54% (13/24) of the tumours. In RET and CDKN1B genes only previously described, non-pathogenic variants were found. Cyclin D1 protein was overexpressed in 13% (3/24) of tumours. CONCLUSIONS: These results suggest that MEN1 alterations, remarkably intragenic deletions, may represent the most prevalent genetic alteration in sporadic parathyroid tumours.

Head and neck basal cell carcinoma prevalence in individuals submitted to childhood X-ray epilation for tinea capitis treatment.

BACKGROUND: A higher prevalence for basal cell carcinoma (BCC) has been associated with radiation, namely with tinea capitis epilation treatment. OBJECTIVE: To evaluate the prevalence of head and neck basal cell carcinoma (BCC) and to identify the major risk factors for BCC in individuals irradiated in childhood for tinea capitis treatment. METHODS: We clinically observed 1,308 individuals from an original cohort of 5,356 irradiated between 1950 and 1963, registering previous skin lesions excisions and proposing for surgery all the suspicious lesions detected. In 585 participants, 47 with BCC, the skin pigmentation was measured. RESULTS: The overall prevalence of BCC was 8.0% and of multiple BCC was 2.4%. Both total (14.7%) and multiple BCC (6.6%) were significantly more common in the individuals who had received a higher radiation dose. Multiple BCC was more prevalent (3.7%) in younger irradiated individuals and total BCC (9.4%) in women. Participants with BCC and without BCC presented similar skin pigmentation. CONCLUSION: Younger age at irradiation, higher dose and female gender increased the risk of developing BCC in these irradiated individuals.

Germline succinate dehydrogenase subunit D mutation segregating with familial non-RET C cell hyperplasia.

C cell hyperplasia is associated with medullary carcinoma of the thyroid in the inherited MEN2 syndromes, in which the great majority of cases have been shown to be due to a mutation in the RET oncogene. We report a study of a family with C cell hyperplasia and hypercalcitoninemia in which no cases of medullary carcinoma have yet occurred and which lacked an identifiable causative RET mutation. Four of the family members showed hypercalcitoninemia, and marked C cell hyperplasia was present in each of the three in whom thyroidectomy has been performed. We investigated the possible involvement of the SDHD gene, because somatic and germline mutations in this gene have been found in a variety of tumors of neural crest-derived tissue. A germline mutation in exon 2 of the SDHD gene (c149 A-G, His 50 Arg) was found in six members of the family; all the four available members with hypercalcitoninemia possessed the mutation. One of the five available members without hypercalcitoninemia, an 18-yr-old female, also showed the mutation. We conclude that we have identified a new syndrome, characterized by familial non-RET C cell hyperplasia. Our studies suggest that a mutation in SDHD may be causative. These observations have implications for apparently incidental cases of hypercalcitoninemia or C cell hyperplasia.