RESUMO
OBJECTIVES: To evaluate the expression and differential diagnostic significance of CyclinD1 and D2-40 in follicular neoplasm (FN) and other thyroid adenomatoid lesions. METHODS: A total of 144 cases of thyroid adenomatoid lesions were enrolled. Immunohistochemistry for CyclinD1 and D2-40 was performed. RESULTS: We found two patterns of CyclinD1 expression: nuclear (N) and cytoplasmic (C). The expression of N-CyclinD1 / C-CyclinD1 in FN (77.4%, 48/62; 50.0%, 31/62) was much higher than that in multinodular goiters with dominant nodules (MNG-DN) (16.4%, 10/61; 4.9%, 3/61) (p < 0.05). In contrast, the expression of D2-40 in MNG-DN (82.0%,50/61) was much higher than that in FN (4.8%, 3/62) (p < 0.05). In addition, unique staining patterns were observed: CyclinD1 showed no immunostaining only in all 8 cases of oncocytic cell tumors (OCT); D2-40 staining showed the characteristic wide distribution of lymphatic vessels in all 8 cases of poorly differentiated thyroid carcinoma (PDTC). Finally, the expression of CyclinD1 and D2-40 did not differ among follicular thyroid adenoma and follicular thyroid carcinoma / noninvasive follicular thyroid neoplasm with papillary-like nuclear features (p > 0.05). CONCLUSIONS: CyclinD1 and D2-40 are helpful diagnostic markers of FN, which can assist to discern FN from MNG-DN / OCT / PDTC.
