Tumores da tiróide e paratiroide em doentes submetidos a radiação para tratamento de tinea capitis

A tinea capitis (tinha) atingiu proporções epidémicas nas décadas de 50-60 em Portugal, tal como ocorreu noutros países, tendo tido realizada a epilação do couro cabeludo das crianças infectadas através dos raios-X, combinada com a aplicação local de antifúngicos.

Tivemos acesso a uma coorte de pessoas tratadas desta forma, da qual observámos clinicamente 1375, procurando fazer o despiste da patologia da tiróide e dos adenomas da paratiroide. A frequência de carcinoma da tiróide (2.8%) foi superior à que se regista em indivíduos não irradiados, mas a frequência de adenoma da paratiroide foi idêntica à dos indivíduos não irradiados. Os resultados obtidos neste estudo realçam a necessidade de fazer o seguimento das pessoas irradiadas na infância com doses baixas de radiação, relativamente à patologia da tiróide.

Autores e Afiliações:

Paula Boaventura¹, Dina Pereira¹, Adélia Mendes¹, José Teixeira-Gomes¹, Manuel Sobrinho-Simões^{1, 2, 3}, Paula Soares^{1, 2}

1- IPATIMUP - Institute of Molecular Pathology and Immunology of the University of Porto, 4200-465 Porto, Portugal

2 - Medical Faculty, University of Porto, 4200 - 319 Porto, Portugal

3 - Department of Pathology, Hospital S. João, 4200 - 319 Porto, Portugal

Abstract:

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.

Revista: Virchows Archiv

Link: http://www.ncbi.nlm.nih.gov/pubmed/25146169