Case #40 Discussion

Summary: The patient complains of a soft tissue enlargement of the tongue that is nonpainful and has increased in size since it was first noticed over a year ago.  The lesion is a well-circumscribed, exophytic, 1.0 x 1.0 cm soft tissue enlargement of the right posterior lateral border of the tongue.  The lesion does not bleed during examination.  It is firm, nontender, and fixed to the surface mucosa and underlying structures.  The surface of the lesion has the same color and texture as the normal surrounding mucosa of the dorsum of the tongue and it does not blanch. Lesions to Exclude from the Differential Diagnosis: The lesion is described as a soft tissue enlargement.  From the category of soft tissue enlargements, reactive lesions can be excluded because the enlargement in this case is persistant, progressive, and not painful. Within the category of tumors, malignant tumors and soft tissue cysts may be excluded.  Malignant tumors are excluded from the differential diagnosis because the lesion in this case is slowly growing, well-circumscribed, asymptomatic, and covered by normal mucosa.  Soft tissue cysts are excluded because these are compressible. Epithelial lesions may be excluded from the category of benign tumors because these lesions have a yellow or white, rough surface.  From the category of benign mesenchymal tumors, the following lesions are excluded.  Epulis fissuratum is excluded because it is associated with the flange of a denture.  Peripheral ossifying fibroma and peripheral giant cell granuloma are excluded because these lesions are found only on attached gingiva or alveolar mucosa.  Hemangioma, lympangioma, and congenital epulis are excluded because these lesions are present at birth or appear in early childhood.  Pyogenic granuloma is excluded because this lesion has a vascular appearance and blanches upon pressure.  Lipoma is excluded because it is compressible to palpation.  Neuroma can be excluded because these are painful to palpation. Lesions to Include in the Differential Diagnosis:  Irritation fibroma, granular cell tumor, leiomyoma, rhabdomyoma, neurofibroma, and schwannoma, are included. Salivary gland tumors, both benign and low-grade malignant tumors, are included in the differential diagnosis.  These lesions include pleomorphic and monomorphic adenomas, polymorphous low-grade adenocarcinoma, adenoid cystic carcinoma, and acinic cell carcinoma.  Low-grade mucoepidermoid carcinoma is unlikely because it is filled with mucus and is compressible. Note that lesions that are typically encapsulated and freely-movable, such as schwannoma and salivary gland adenomas, would be fixed to surrounding structures when located on the dorsum of the tongue. Management:  Treatment is excisional biopsy which will remove the lesion and allow for microscopic diagnosis.  Final Diagnosis: Granular cell tumor. The dorsum of the tongue is the most common location for granular cell tumor, but it can also be found on any oral mucosal surface.  Sometimes the mucosa overlying a granular cell tumor is white and rough because of epithelial hyperplasia; however, a normal mucosal covering does not exclude granular cell tumor.  The prognosis of granular cell tumor is good, and recurrence is rare.