Congenital Granular Cell Epulis: Classic Presentation and Its Differential Diagnosis.

Congenital granular cell epulis (CGCE) is an uncommon lesion of unclear pathogenesis. It occurs predominantly in female newborns with a predilection site of the maxillary alveolar ridge. The mass enlarges prenatally but the growth arrests after birth. Histologically, CGCE is characterized by a proliferation of polygonal cells with eosinophilic, granular cytoplasm and eccentric, bland-appearing nuclei. It closely resembles adult granular cell tumor (GCT) microscopically and S-100 immunostain is often helpful in distinguishing the two (S-100-positive in GCT and S-100-negative in CGCE). Clinically, the lesion should also be distinguished from entities such as infantile myofibroma, rhabdomyoma, melanotic neuroectodermal tumor of infancy, peripheral odontogenic fibroma, and neurofibroma. CGCE demonstrates an excellent prognosis and has not been associated with any syndromes/genetic defects or malignant transformation. Clinicians and pathologists should be familiar with this rare entity and its differential diagnosis for accurate diagnosis and management.