Cyclooxygenase-2 and Inducible Nitric Oxide Synthase Expression in Thyroid Neoplasms and Their Clinicopathological Correlation

To evaluate the expressions of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in thyroid neoplasms in a Korean population, we studied a total of 154 cases: papillary carcinoma of classical type (PTC), 86; follicular adenoma (FA), 21; follicular carcinoma (FC), 35; medullary carcinoma (MC), 3; undifferentiated carcinoma (UC), 5; and Hurthle cell neoplasm (HN), 4. Using immunohistochemical staining, COX-2 expression was detected in 62 (72.1%) PTC specimens, 5 (23.8%) FA specimens, 10 (28.6%) FC specimens, 0 (0.0%) MC specimens, 1 (20.0%) UC specimen, and 3 (75%) HN specimens. iNOS expression was detected in 66 (76.7%) PTC specimens, 4 (19.0%) FA specimens, 13 (37.1%) FC specimens, 0 (0.0%) MC specimens, 3 (60.0%) UC specimens, and 4 (100%) HN specimens. The results showed that COX-2 and iNOS were frequently expressed in the PTC and HN specimens, and iNOS was more frequently overexpressed in the FC specimens than in the FA specimens. In PTC, COX-2 and iNOS were significantly overexpressed in patients over 45 yr of age (p=0.029, p=0.041), and iNOS expression was increased in patients with a large primary tumor (p=0.028). These results suggest that the upregulation of COX-2 and iNOS may contribute to the tumor progression of thyroid gland, particularly in PTC and HN, and iNOS may play an adjuvant role during the tumor progression of FC.

Squamous Cell Carcinoma Arising in Mature Cystic Teratoma of the Ovary: a Report of Six Cases and Immunohistochemistry of the p53 Protein and p21WAF1/CIP1

BACKGROUND: Mature cystic teratoma is a common type of ovarian tumor. Although squamous cell carcinoma (SCC) is the most common carcinoma in malignant transformations of ovarian mature cystic teratomas, SCC arising in a mature teratoma is rare. METHODS: This paper reports four cases of invasive SCC, a case of an adenosquamous cell carcinoma and a case of a pure in situ SCC arising in a mature cystic teratoma including a clinicopathological evaluation and an immunohistochemical study of the p53 protein and p21WAF1/CIP1. RESULTS: The mean age of the patients was 60 years. The sizes of the mature cystic teratomas in all cases were greater than 7.5 cm in the largest diameter. Five cases showed the nuclear accumulation of the p53 protein with no p21WAF1/CIP1 immunoreactivity. The other case showed the nuclear accumulation of p21WAF1/CIP1 without p53 expression. There was a significant inverse relationship between the p53 protein level and p21WAF1/CIP1 expression. CONCLUSION: A clinicopathological evaluation showed that a SCC arising from a mature cystic teratoma must be included in a differential diagnosis when the patient is over 42 years of age and the size of a mature cystic teratoma is greater than 75 mm in the largest diameter. It is suggested that p53 overexpression is implicated in the malignant transformation, and the p21WAF1/CIP1 expression level is dependent on alterations in the level of the p53 protein in these tumors.