Congenital epulis: immunohistochemical findings of 12 cases

Congenital epulis is a fairly rare soft tissue tumour occurring exclusively on the alveolar ridge of newborns. The exact origin of congenital epulis is still debatable. The objective of the study is to determine the clinicopathological features and immunohistochemical findings of congenital epulis. A retrospective study was carried out to determine the clinicopathological features of congenital epulis, diagnosed histologically in the main oral histopathology laboratory in Malaysia from 1967 to 2014. Immunostaining using vimentin, muscle specific actin, smooth muscle antigen, desmin, S100, CD34, CD68 and CD1a was carried out. Twelve cases of congenital epulis were reviewed. All of the patients were females and the presentation age ranged from 2 to 90 days. The patients comprised of 6 Malays, 3 Chinese, 2 Indians and 1 Orang Asli. Most of the cases (n=7) involved the maxillary ridge and presented as pedunculated well-defined lumps (n=8). Excisional biopsy was performed in all cases. Via immunohistochemistry, vimentin expression was observed in all cases; but negative for CD34, muscle specific actin, smooth muscle antigen, and desmin. CD1a and S100 positivity was seen in five cases. The interstitial cells were highlighted by CD68. Although congenital epulis has been first described 130 years ago, the exact nature of its histogenesis remains a mystery.