An otherwise-healthy 2-year-old Japanese female presented with a polyp-like lesion on the palatal surface at the incisive papilla. The appearance of the lesion was similar to that of a congenital epulis. The histological findings showed proliferating mesenchymal components that contained mainly smooth muscle admixed with collagen fibres, nerve fibres, small vessels and mucous salivary glands. The immunohistochemical staining findings for α-smooth-muscle actin, desmin and S-100 protein were all positive. The histological diagnosis was therefore leiomyomatous hamartoma, based on clinical microscopic observations.
Hamartomas are defined by A lberecht as ‘tumour-like, but primarily non-neoplasic, malformations or inborn errors of tissue development, characterized by an abnormal mixture of tissue indigenous to the part with an excess of one or more of these’. Hamartomas may occur in any organ of the body, and are frequently located in the spleen, liver, kidneys, lungs, and pancreas, but are uncommon in the oral region, and reports of oral hamartomas, although rare, have mostly been located in the gingiva.
Congenital growths histologically defined as leiomyomatous hamartomas in the midline of the maxillary gingival are to the authors’ knowledge extremely rare, with only 9 reported cases ( Table 1 ) . Although the clinical features in all reported cases were similar to those of congenital epulis, the histological findings differed from congenital epulis, which is a granular cell tumour. The authors report a rare case of leiomyomatous hamartoma in the midline of the maxillary gingival (incisive papilla) that was observed in an 18-month-old female presenting with a congenital epulis, and describe the tissue composition as revealed by immunohistochemical investigations.
|Authors||Year||Age||Sex||Location||Age at presentation||Size (cm)||Clinical diagnosis|
|1. T akahashi et al.||1962||2.5m||F||Median maxilla||Noticed at 20 days||0.4 × 0.5 × 0.7||Congenital epulis|
|2. M ushimoto et al.||1982||11m||F||Median maxilla||Present at birth||0.5 × 0.5 × 0.7||Congenital epulis|
|3. K ajiyama et al.||1983||4y5m||F||Median maxilla||Noticed at 5 months||1.5 × 0.6 × 0.7||Congenital epulis|
|4. K anekawa et al.||1989||3y||M||Median maxilla||Present at birth||0.5 × 0.5 × 0.5||Congenital epulis|
|5. S eki et al.||1991||2y3m||F||Median maxilla||Present at birth||0.8 × 0.5 × 0.4||Congenital epulis|
|6. S emba et al.||1993||2y2m||M||Median maxilla||Present at birth||0.5 × 0.5 × 0.4||Congenital epulis|
|7. M isawa et al.||1994||1y7m||F||Median mandible||Present at birth||0.3 × 0.2||Congenital epulis|
|8. T akeda et al.||2000||10m||M||Median maxilla||Present at birth||0.6 × 0.6 × 0.6||Congenital epulis|
|9. I ida et al.||2007||2y7m||M||Median maxilla||Noticed at 2y 5months||0.5 × 0.3 × 0.4||Begin tumour|
|10 * . Present case||2008||2y||F||Median maxilla||Noticed at 5 months||0.5 × 0.5 × 0.7||Congenital epulis|
An 18-month-old Japanese female was referred to Kyushu Dental College Hospital for the evaluation and treatment of a polypoid mass in the midline of the maxillary gingiva (incisive papilla). The lesion was asymptomatic, and according to the mother was first clearly noticed at 5 months of age and had since grown slowly. She had delivered normally at full-term and there were no abnormal events during pregnancy and no history of congenital anomalies in her family. The nodule was fibrous on palpation and covered by a normal mucosa. There were no palpable lymph nodes in the region.
Intra-oral examination revealed the presence of a polypoid mass in the midline of the maxillary gingiva (incisive papilla) ( Fig. 1 ). The mass was painless, with a clear border and had an elastic and soft, pedicellation, measuring 0.5 × 0.5 × 0.7 cm, and a smooth covering surface that was of normal colour. Radiographic examinations did not reveal any radiopaque or radiolucent lesions. The initial clinical diagnosis was congenital epulis. The mass was easily excised under general anaesthesia and the sectioned surface was milky-white. The specimen was submitted for histopathological and immunohistochemical staining.