Congenital epulis (CE) of the newborn is an uncommon lesion, described for the first time in 1871 by Neumann.1 To date, fewer than 200 cases have been described in the literature. 2 This lesion, which usually presents at birth, is multiple in 10% of the cases, 3 has a distinct predilection for females, 4 and is most frequently located on the anterior maxillary alveolar ridge. We report a case of CE observed in a newborn male, with immunohistochemical investigation, in order to provide additional information about the histogenesis of this lesion. Case ReportThe patient was a newborn male, 4100 g in weight, 51 cm in length (Crown-Heel), who presented at birth with a pedunculated neoformation on the anterior maxillary ridge, measuring 10x5x5 mm in size. The lesion was excised at four days of age. The excised mass, which consisted of a pink nodule, was fixed in 10% buffered formalin. The specimen was embedded in paraffin to obtain 4-μm thick sections, and stained with hematoxylin and eosin. Further dewaxed sections were taken for immunohistochemical investigation, using the streptavidin-biotin-alkaline phosphatase method. New fuchsin was used as chromogen. The following antibodies were employed: alphafetoprotein (clone C3, Novocastra Lab., Newcastle-upon-Tyne, UK); carcino-embryonic antigen (CEA) (clone Col-1, Biomeda, Foster City, CA); macrophage marker (clone MAC 387, YLEM, Avezzano, AQ, Italy); lysozyme (polyclonal, Novocastra); CD-68 (clone KP1, Biomeda); NSE (clone 5E2, Biomeda); desmin (clone 33, Biomeda); S-100 protein (clone MIG-5, Biomeda); vimentin (clone V9, Biomeda); muscle-specific actin (clone HHF-35, Biomeda); leukocyte common antigen (clone X16/99, Novocastra); estrogen receptors (clone 1D5, DAKO SpA, Milano, Italy); and progesterone receptors (clone 1A6, DAKO). Positive and negative controls were performed in parallel for all the antibodies tested, and all antibodies were prediluted.Microscopic examination showed a highly vascularized tissue, mainly composed of nests of polygonal cells, with large clear and granular cytoplasm and a small nucleus. The overlying mucosa showed normal squamous epithelium with focal ulcerations. Also present were infiltrates of polymorphonuclear leukocytes within the neoformation (Figures 1 and 2).The results of the immunohistochemical investigation were graded as negative (-), weakly positive (+), moderately positive (++) or strongly positive (+++), and are summarized in Table 1. A sharp positivity was observed only for vimentin, whereas desmin appeared focally and moderately positive. All other antibodies were negative. Six years after surgical excision, the patient was well and no local recurrence had been observed.