Introduction: Peripheral Giant Cell Granuloma (PGCG) is recognized as a reactive lesion in oral cavity which demonstrates a marked gender predilection with more prevalence within females suggesting a possible role for steroid hormones (estrogen and progesterone) in pathogenesis, development and progression of the lesions. Therefore, this study aimed to the investigate the existence and distribution of estrogen and progesterone receptors in PGCG of the oral cavity.

Methods: In this case control study, Hematoxylin and Eosin (H&E) and Immunohistochemical staining were performed on 10 PGCG paraffin blocks and 10 samples of normal gingival mucosa using estrogen and progesterone antibodies. The percentage of positive cells was determined using scaled eyepiece. The study data were then analyzed via SPSS software (ver.15) using Chi- square test.

Results: In 10 cases of PGCG, estrogen and progesterone receptors demonstrated negative staining in osteoclastic giant cells, stromal cells, blood vessels, endothelial cells and oral mucosal epithelium. The staining for all samples of normal gingival mucosa was reported to be negative, as well (P value PR=0.220,
P value ER=1.250).

Conclusion: The findings of this study revealed no expression of estrogen and progesterone receptors in oral cavity PGCG. As a result, other factors expect for sexual hormones may be effective in progression and development of this lesion.