C. Koerber et al., Increased I-131 uptake in local recurrence and distant metastases after second treatment with retinoic acid, CLIN NUCL M, 24(11), 1999, pp. 849-851
We present a case of increased I-131 uptake in a patient with papillary thy
roid carcinoma with local recurrence and distant metastases after a second
treatment with retinoic acid as a sign of redifferentiation of the tumor ce
lls. When fine-needle aspiration cytology before and after a second course
of retinoic acid treatment were compared, signs of tumor cell redifferentia
tion were found, This was accompanied by biochemical reexpression of thyroi
d marker proteins.