CASE REPORTS   

Minerva Endocrinologica 2000 March;25(1):29-32

Copyright © 2000 EDIZIONI MINERVA MEDICA

language: English

Abnormally high TSH in subjects with thyrotoxicosis affected by congenital hypothyroidism. Case report

Alberto G. ¹, Novi R. F. ¹, Trombetta A. ¹, Maurino M. ¹, Seardo M. A. ¹, Brossa C. ¹, Messina M. ²

¹ From the Department of Internal Medicine, University of Turin; ² Division of Endocrinology, Maria Vittoria Hospital, Turin

Inappropriate secre­tion of TSH (IST) ­refers to a het­er­o­ge­ne­ous ­group of syn­dromes in ­which ­patients ­show unsup­pressed TSH lev­els in ­spite of ­high ser­um ­free thy­roid hor­mone con­cen­tra­tions. It has ­been rec­og­nised ­that IST can be due to ­both thy­roid hor­mone resis­tance (RTH) and pitui­tary TSH-secret­ing ­tumours. The for­mer can be gen­er­al­ised (­GRTH) or pitui­tary (PRTH) if the resis­tance is ­more ­severe in the pitui­tary ­than in the ­rest of the tis­sues. This ­case ­report ­points out the per­sis­tence of ­this ­patient’s TSH resis­tance to the inhi­bi­tion of ­high con­cen­tra­tions of cir­cu­lat­ing thy­roid hor­mones ­with ­clear symp­toms of thy­ro­tox­ic­o­sis ­even ­after ­many ­years of replace­ment ther­a­py; it ­also sug­gests ­that in ­this ­case FT4 is the param­e­ter to eval­u­ate the ­therapy’s effec­tive­ness.