What Is Inverted Ductal Papilloma?
Oral papilloma is a benign tumor that primarily impacts the oral mucosal membranes in the mouth.These papillary tumors or lesions always normally show a specific type of exophytic growth and possess a polypoid or sometimes a verrucous appearance. Inverted ductal papilloma is a specific variety or subtype of these tumors and are uncommon occurring in the oral cavity.They may be present with a clinical appearance similar to most oral papillary lesions.The cause of this disease is elusive, but according to some research authors and from documented cases in dental literature, this condition can be linked to the human papillomavirus (HPV) infection .
Why Is It Called Inverted Ductal Papilloma?
Inverted ductal papilloma of the oral cavity (IDPOC) was first originally described in the year 1982 by White et al. Originally it had been described as a benign tumor that was located in the secretory ducts of the minor salivary glands. However, the diagnostic challenges for oral surgeons started when there was a histological similarity of these tumors to intraductal papillomas (IP) of the sinus, nasal, bladder, and oral mucosa. Hence the terminology of “inverted ductal papilloma of the oral cavity” was in particular reference to the submucosal and nodular lesions impacting only the secretory duct outlets of the salivary glands.These salivary gland tumors of the oral cavity can be differentiated from other similar papillomas or papillary groups of tumors .
Where Is the Location of Tumor?
According to case reports, the affected patients suffering from IDPOC lesions can report changes in the size of the lesions that may vary because of the internal accumulation of the mucoid material particularly observed mostly on the lower lip mucosa followed by the cheek mucosa and the floor of the mouth.
What Is the Etiology of Tumor?
These benign tumors would be prevalent more in the age group between 27 to 65 years as per research reports with the fourth to fifth-decade age group being the most affected. These tumors would be slow-growing and develop over a period of three to six years as per medical research with another common cause of local trauma. Local trauma repeatedly in the oral cavity such as trauma to the lips, floor of mouth, or cheek mucosa can cause IDPOC lesions to aggravate and evolve over time.
What Are the Clinical Features of Inverted Ductal Papilloma Tumors?
Due to their painless nature, asymptomatic characteristics, slow growth, and benign or infrequent occurrences, these tumors could be mistakenly diagnosed by oral surgeons or dentists as other benign neoplasms or tumors in the oral cavity.The important feature in diagnosing IDPOC lesions is that firstly the lesions present with a papillary appearance and they only originate mainly within the secretory ducts of the salivary glands. The most common location of these lesions is usually in the minor salivary glands of the lip only. reports have also been documented rarely in the lower cheek mucosa region as well.
There would be other clinical variations in their appearance. Rarely they may present as endophytic or inverted growths too.Inverted ductal papillomas in the oral cavity would also appear quite similar to other papillary lesions that may be located for instance in other parts of the body such as the nasal and paranasal sinuses or the sinus or paranasal sinus mucosa, from the urinary bladder or from papillary lesions of the lacrimal gland. Inverted ductal papilloma of the oral cavity (IDPOC) are usually more challenging to diagnose and can be only histopathologically confirmed for a final diagnosis.
What Is the Histopathology of Inverted Ductal Papilloma of Oral Cavity and Its Differential Diagnosis?
Upon Histopathological examination, these lesions are diagnosed by their organized cell patterns within a non-encapsulated lesion and with characteristic papillary crests forming multicystic spaces. These tumors are spread in a rather organized manner beneath the oral connective tissues that can differentiate it from other benign or malignant oral neoplasms or cancers .
Papillomas of the oral cavity or also called papillary oral tumors are varied in origin and need to be considered for differential diagnosis for inverted ductal papillomas of the oral cavity or specifically of the salivary glands (IDPOC). Some papillary lesions affecting the secretory ducts of salivary glands- like a range of conditions for example oncocytoma, papillary cystadenoma, Warthin’s tumor, intraductal papilloma, sialadenoma papilliferum are all papillary tumors of the oral cavity only .
What Is the Link in Between These Benign Tumors and HPV Infections?
The etiology as per some research authors is related to the onset of human papillomavirus (HPV) infection. This is because, in individuals affected by this benign neoplasm of IDPOC, some cases have been detected with HPV sequences or specific subtypes when the lesions were specifically analyzed.Several immunohistochemical as well as ultrastructural studies have been made to reveal the findings of these benign oral papillomas. According to immunohistochemical and ultrastructural analyses, IDPOC lesions are primarily identified as originating within a transition zone. These tumors develop between the distal ends of the secretory ducts of the minor salivary glands, precisely at the junction of the secretory ducts and the superficial or surface epithelium of the oral cavity. Consequently, both immunohistochemical and ultrastructural findings can be valuable in diagnosing these intricate oral tumors associated with IDPOC.
What Are Treatment and Recurrence Rates?
The main line treatment strategy for eliminating and avoiding the recurrence of these benign tumors is by surgical removal of the lesions. Surgical treatment is the only known major choice by the maxillofacial surgeon in treating IDPOC tumors. Post-surgery benign tumors usually are not associated with any relapse as such and no scope for malignant transformation post-surgical resection or removal of the lesion has been reported according to medical and dental research. Hence IDPOC lesions have an excellent prognosis especially when they are diagnosed timely and are treated promptly by the oral and maxillofacial surgeon .
Conclusion:
IDPOC is a challenging, but benign lesion with a good prognosis after surgical resection. Also, all the different oral papillomas or benign tumors need to be differentially diagnosed before the dental surgeon arrives at a final diagnosis.It is crucial that the dentist or oral surgeon and Oral pathologist should clearly relate their clinical findings with the histopathological findings to come to a confirmative timely diagnosis- that can improve patients' recovery and prognosis.
