Aim: To evaluate serum (SMK) and nodular (NMK) midkine levels in thyroid nodules and explore its relevance to ultrasound feature/pathological results.
Methods: A total of 80 patients (56 women, 24 men) with thyroid nodules were included in this prospective study. Hemograms, thyroid function tests, fine needle aspiration biopsies, ultrasonographic evaluation were routinely made. In addition, levels of SMK and NMK were measured. Any possible correlations between SMK, NMK and biochemical or radiological variables under investigation were sought.
Results: The average age of study group was 51.9±14.4. Both SMK and NMK were found to be higher in hypoechoic nodules with an irregular border and absent halo. Serum MK levels were significantly higher in nodules containing microcalcifications than the macrocalcification or without calcification (P=0.001). Serum MK levels were high in patients with differentiated thyroid carcinoma, compared to patients with follicular adenoma or nodular hyperplasia. Serum MK levels seemed to correlate with nodular MK levels (r=0.54, P<0.001).
Conclusion: Results of the current study showed that both SMK and NMK were indicators of highly malignant/suspicious thyroid cytopathology and also correlate well with sonographic features of thyroid malignancy. We suggest that Midkine may serve as a novel biomarker in conjunction with the cytopathological results in preoperative assessment of thyroid nodules.