Three days after the birth of a black female, two lumps were noticed in her mouth. No other oral abnormalities were noted. The lumps did not interfere with feeding or breathing. The mother was HIV-seropositive and had been receiving Neveripine since before the pregnancy. The mother would not allow the HIV-serostatus of the baby to be investigated.
On examination there were two firm pedunculated nodular lesions (Fig 1), one on the anterior maxillary ridge, 7.5 × 5 mm in size, and the other further posteriorly in the middle of the palate, 6.5 × 5 mm in size (Fig's 2A and 2B).
The differential diagnosis included congenital granular cell tumour (CGCT), odontogenic tumour, teratoma, neuroectodermal tumour, haemangioma and fibroma with a provisional diagnosis of CGCT. Both lesions were excised under general anaesthesia when the baby was 9 days old. Post-operative healing was uneventful.
Microscopic examination of the lesions showed round or ovoid cells with granular eosinophilic cytoplasm and centrally located nuclei (Fig 3). The masses were covered with a thin stratified squamous epithelium. The definitive diagnosis was CGCT.
CGCT is uncommon and occurs almost exclusively in Caucasian newborns [1]. It is a well defined pedunculated nodule or mass, with a smooth or lobulated surface and is most frequently located on the masticatory mucosa of the maxillary alveolar process. The male to female ratio is 1:8 [4, 5]. CGCT can vary in size from several millimeters to several centimeters. Only 10% of subjects with CGCT present with multiple lesions that may affect one or both jaws [2, 3]. The condition is not associated with any other congenital abnormalities. Large lesions may interfere with breathing and with feeding [5]. Other than the gingiva, the tongue is the only site rarely affected by CGCT [2, 3].
CGCT occurs only in the newborn and is a distinct pathological entity [6]. It may be identified by prenatal sonography, but the findings are not specific and the ultrasonic differential diagnosis would include congenital malformations and various benign or malignant tumours [4].
Local excision is curative. If left untreated malignant transformation never occurs. Spontaneous regression of untreated lesions has been reported [1, 3, 5, 7]. CGCT appears to be more hamartomatous than neoplastic [1, 2].
The histogenesis of CGCT is obscure. Its possible origin may be odontogenic, fibroblastic, histiocytic, myogenic or neurogenic cells [1–5, 7], or perhaps pluripotential precursors of these cells. The reason for the development only on the alveolar masticatory mucosa or on the tongue remains unexplained [2, 3, 6–8].
Microscopically, CGCT typically consists of large closely packed polygonal cells with clear granular eosinophilic cytoplasm and centrally positioned nuclei, within a vascular fibrous connective tissue stroma, covered with squamous cell epithelium [1–10]. The granular cells stain positively for vimentin and negatively for S100-protein, oestrogen and progesterone receptors [5, 6]. Electron microscopic examination of the granular cells of CGCT shows heterogeneous electron-dense granules, lysosomes, and cytoplasmic lipid droplets [6]. CGCT and granular cell tumour found only in older people have similar microscopic features. However, the latter is less vascular and is typically covered by hyperplastic squamous cell epithelium [1, 4].