Differential expression of Phophatase and Tensin Homologue in normal, hyperplastic and neoplastic endometrium

Objectives: To observe the differential expression of phophatase and tensin homologue in normal proliferative, hyperplastic and malignant endometrial lesions. Methods: The retrospective study was based on the analysis of endometrial samples, both hysterectomies and curettage, received at the department of pathology Basic Medical Sciences Institute at the Jinnah Postgraduate Medical Centre, Karachi, from January 1, 2006 to December 31, 2010. A total of 55 endometrial samples were analysed for morphological features and results of immunohistochemical staining. Results: Of the 55 samples, 25 (45.45%) were malignant endometrial lesions, 6 (10.9%) complex hyperplasias with atypia, 14 (25.45%) complex hyperplasias without atypia hyperplasia, 6 (10.9%) simple hyperplasias without atypia, and 4 (7.27%) normal proliferative endometrium. Among malignant endometrial lesions, 12 (48%) showed complete loss of phophotase and tensin homologue expression out of which majority were endometroid adenocarcinoma. Five (83.3%) cases of complex hyperplasias with atypia and 9 (64.28%) cases of complex hyperplasia without atypia showed complete loss of or diminished expression of phophotase and tensin homologue. Conclusion: Loss of phophotase and tensin homologue expression was seen in a significant number of well differentiated endometrial adenocarcinomas and complex hyperplasias with atypia suggesting loss of PTEN expression as an early event in endometrial carcinogenesis.