DYSHORMONOGENETIC GOITER - A MORPHOLOGICAL AND IMMUNOHISTOCHEMICAL STUDY

A retrospective morphological and immunohistochemical study of 21 case s of dyshormonogenetic goiter was carried out correlating patterns of hyperplasia and the atypias of the glandular tissues with specific def ects in hormonal synthesis, including (1) thyroglobulin synthesis defe ct (Group I, n = 8); (2) defective organification of iodide (Group II, n = II); and (3) iodide transport defect (Group III, n = 2). Microfol licular, trabecular, papillary, and oxyphilic cell patterns were more frequent in Group II compared with Group I (Group III was excluded bec ause of the small number of cases). The combined microfollicular and t rabecular patterns were more frequently seen in patients in Group II. Two cases of thyroglobulin synthesis defect demonstrated certain morph ological specificity characterized by an alveolar pattern. Atypias wer e more frequent and severe in patients in Group II relative to patient s in Group II but features of malignancy were not found in any patient s. Immunohistochemical study using thyroglobulin antiserum demonstrate d correlation between morphology and positivity of follicular cells. S carce C cells were verified in these cases by immunohistochemistry. Us ing two-paired samples, respectively, of 21 endemic and 21 dyshormonog enetic goiters, we distinguished 85.7% of the cases examined, presente d in a double-blind fashion. Scarcity of colloid and prominent cellula r atypia were highly suggestive of dyshormonogenetic goiter. Consideri ng the relative rarity of dyshormonogenetic goiter, our studies point out the most common patterns of hyperplasia and atypias in this pathol ogy to avoid misdiagnosis, principally when considering the possibilit y of malignancy.