SUMMARY -Th e aim of the study was to determine the infl uence of RET, p27 and cyclin D1 on regional lymph node metastases in papillary microcarcinoma. Th e analysis included 70 patients with papillary thyroid microcarcinoma that underwent surgery at Split University Hospital Center between 1999 and 2001. Immunohistochemistry was performed on formalin-fi xed, paraffi n-embedded tissue by the RET, p27 and cyclin D1 antibodies. Quantifi cation was based on the intensity and distribution of nuclear staining, dividing tumors into those that showed expression (expressors) and those that showed no expression (non-expressors). Univariate analysis using χ²-test and Fisher exact test was performed with the level of statistical signifi cance set at p<0.05. Th ere was no statistically signifi cant diff erence in the incidence of metastases according to the expression or non-expression of RET mutation (χ²-test: p=0.459; Fisher exact test: p=0.672). Among 25 cases with cyclin D1 expression, 6 had metastases, whereas only 2 of 45 cases with no cyclin D expression had metastases (χ²-test: p=0.014; Fisher exact test: p=0.021), indicating that the expression of cyclin D1 is not crucial for the development of metastases in lymph nodes. In contrast, analysis of p27 expression showed it to be signifi cantly associated with lymph node metastasis because 3 of 45 patients with p27 expression had metastases, indicating a statistically signifi cant correlation between p27 expression and lymph node metastases (χ²-test: p=0.093; Fisher exact test: p=0.124). Th is study confi rmed the importance of the evaluation of RET, p27 and cyclin D1 expression and demonstrated the validity of their application in the assessment of microcarcinoma behavior.

The aim of this report is to present a rare case of papillary thyroid cancer metastasis to the kidney manifesting with obstructive nephropathy. A 68 year-old man was referred to ultrasound examination because of a multinodular goiter. Ultrasound guided fine needle aspiration biopsy (US-FNAB) suggested follicular adenoma of the right thyroid lobe and a right lobectomy with isthmectomy was performed. Pathohistologic findings confirmed a follicular variant of papillary thyroid carcinoma and the patient underwent a total thyroidectomy followed by radioiodine ablation. A few years later, scintigraphy revealed radioiodine avid metastatic foci in the right kidney as well as an intramuscular lesion in the left thigh. At the same time, non-small cell lung cancer was diagnosed. Papillary thyroid carcinoma is the most common thyroid malignancy, but renal or muscular metastases are extremely rare in this type of cancer and can be found in poorly differentiated cancers, which should be clearly stated in the final pathohistologic report. In order to better the interpretation of these pathohistological findings and allow successful monitoring of these patients, close cooperation with pathologists and immunohistochemical profiling is suggested.