Endocrine Abstracts

Introduction: Characteristic localisations of metastases of differentiated thyroid carcinoma (DTC) include local lymph nodes, the lungs and bones, while the incidence of DTC metastases onto the liver, the brain and skin is clearly lower. The localisation of metastases in other organs, including the kidneys, is very rare.

Material and methods: A case of a 73–year-old patient with thyroid oxyphilic carcinoma is reported, the case being diagnosed in 1997, after thyroidectomy and thyroid remnants ablation with ¹³¹I. Since the year 2000, recurrent cervical lymph metastases have been observed. The metastases were surgically treated (five subsequent lymphadenectomies) and the patient received ¹³¹I therapy (the total dose, administered during the years 2000–2002, amounted to 31 GBq); after the last operation, performed in August 2002, the patient presented with hyperthyroglobulinaemia (454 ng/mL). In November 2002, the patient received 8.4 GBq of ¹³¹I, following preparation with cis-retinoic acid, because of the lack of iodine uptake foci in whole body scintigraphy, performed after previous radioiodine administration. No iodine avid foci were found on post-therapeutic scintigrams, nor was any decrease in Tg concentration found in later observations. During follow-up (December 2003), focal changes were observed in both kidneys (US, CT). Fine-needle aspiration biopsy of those changes indicated their DTC metastatic character. The patient did not agree to nephrectomy.

Conclusions: Maintained increased Tg concentrations, despite the lack of clinically overt features of the disease activity, require a determined search for sources of this marker, also in areas which are rarely targeted by DTC metastases.