An adult may present with a mass in the floor of the mouth.
Malignant tumors become more important causes as the person gets older.
Some masses may be the result of cystic lesions present at birth.
Some are detected as incidental findings.
Some are large enough to interfere with breathing and/or feeding.
Malignant tumors in the floor of the mouth:
(1) squamous cell carcinoma, HPV-related
(2) squamous cell carcinoma, not HPV-related
(3) malignant salivary gland tumors (adenoid cystic, mucoepidermoid, etc)
(4) metastatic carcinoma
(5) malignant lymphoma
(6) sarcoma
Benign lesions include:
(1) benign dermoid or teratoid cyst
(2) epidermal inclusion cyst
(3) lipoma
(4) ranula (mucocele on the floor of the mouth related to the sublingual salivary gland)
(5) oral lymphangioma
(6) oral foregut cyst (with respiratory type epithelium and numerous goblet cells)
(7) benign cyst of the sublingual salivary gland
(8) benign tumor of a salivary gland (pleomorphic adenoma, etc)
(9) obstruction of the submandibular duct
(10) abscess
(11) solitary fibrous tumor
(12) benign neural tumor (neurilemmoma, neurofibroma)
(13) thyroglossal duct cyst
(14) hematoma
(15) foreign body
(16) hemangioma or angiomyxoma
(17) hemangiopericytoma
(18) keloid
(19) rhabdomyoma
(20) granular cell tumor
(21) heterotrophic tonsil
where:
• The epidermal inclusion cyst (epidermoid cyst) has an epithelial layer with luminal keratin but no skin adnexal structures. A dermoid cyst has skin adnexal structures.
