Immunohistochemical evaluation and in situ hybridization in a case of oral inverted ductal papilloma

Abstract

Oral inverted ductal papilloma is a rare benign tumor occurring almost exclusively in minor salivary glands. It is thought to originate from the terminal portion of the salivary excretory ducts.’ Batsakis et al probably first described this lesion using the term “epidermoid papillary adenoma.“2 However, it was not until White et al3 reported their series that the name “inverted ductal papilloma” was proposed because the lesion resembles the inverted papilloma of the urinary bladder,4 nasal cavity, and paranasal sinuses.5 Similar lesions have also been described in the renal pelvis6 lacrimal sac,’ cervix,’ and posterior pharyngeal wall.’ Inverted papillomas have been previously described in the oral cavity.‘-’ ’ However, they form from the surface rather than the ductal epithelium. The English literature includes six cases registered in the salivary gland pathology registry at the Armed Forces Institute of Pathology,’ four cases described by White et a1,3 four by Regezi et a1,12 one by Clark et a1,13 and one by Wilson and Robinson.14 If the three cases of epidermoid papillary adenoma by Batsakis et al’ are included, only 19 cases have been reported in the minor salivary glands. The literature contains one example of inverted ductal papilloma originating in the parotid.” Clinically, oral inverted ductal papillomas appear as firm, asymptomatic nodules 1 to 1.5 cm in diameter.‘.3 They occur in adults ranging in age from 32 to 66 years, with a mean age of 50 years.’ No sex predilection has been noted.‘.3,‘“‘4 The lower lip and buccal mucosa