Intraductal papilloma arising from sublingual minor salivary gland: Case report and immunohistochemical study

Intraductal papilloma of the sublingual gland imitating a ranula

Ductal papillomas are rare benign lesions of the salivary glands with two distinctive types, intraductal and inverted. The rarest anatomical location where intraductal papillomas occur is the major salivary glands. In the present study, we report an intraductal papilloma of the left sublingual gland with the relevant clinical, imaging, and histopathological findings and postoperative follow-up. To our knowledge, this is the fourth case of an intraductal papilloma of a sublingual gland to be reported in the international literature. We present this rare case because of its clinical and radiological imitation of a ranula.

Papillary Neoplasms of the Salivary Duct System: A Review

Papillary lesions of the salivary duct systems are uncommon. They encompass a heterogeneous group of benign, intermediate, and potentially aggressive neoplasms. With a few exceptions, historical descriptive terms such as papillary adenocarcinoma, papillary cystadenocarcinoma, and papillary adenoma are being replaced by defined entities, at same time acknowledging the papillary features as a histologic pattern. The evolving genetic landscape of these lesions increasingly permits their reproducible categorization. This article discusses those papillary proliferations encountered in the salivary glands with a focus on intraductal papillary mucinous neoplasms and cystadenomas. Intraductal carcinomas and sialadenoma papilliferum are addressed in separate articles in this issue.

A Rare Case of Intraductal Papilloma Arising from Minor Salivary Gland in the Floor of the Mouth

A 77-year-old woman with a rare oral intraductal papilloma arising from the minor salivary gland located on the floor of the mouth and causing the mucus retention is reported. Microscopically, the lesion was characterized by unicystic cavity exhibiting the lumen partially filled by papillary projections of the ductal epithelium with varying degree of oncocytic metaplasia. Based on the histopathological analysis, the differential diagnosis of oral intraductal papillomas and other ductal neoplasms of salivary origin are discussed.

Intraductal papilloma arising from the accessory parotid gland: A case report and literature review

RATIONALE

Intraductal papillomas of the accessory parotid glands are extremely rare benign tumors that are most commonly derived from minor salivary glands and are easily misdiagnosed as other diseases. Studying these lesions by pathology and immunohistochemistry can raise awareness of the disease, reduce the rate of misdiagnosis, and provide more precise treatments.

PATIENT CONCERNS

A 35-year-old man first presented to our hospital with a 6-month history of a painless mass on his left parotid gland.

DIAGNOSES

The patient was diagnosed with intraductal papilloma of the accessory parotid gland by pathology and immunohistochemistry.

INTERVENTIONS

The mass was completely resected.

OUTCOMES

After 2 years of postoperative follow-up, the patient recovered well without recurrence.

LESSONS

Intraductal papilloma of the accessory parotid gland is very rare, and can easily be misdiagnosed as sialadenoma papilliferum, inverted ductal papilloma, or papillary cystadenoma, among others. It is necessary to analyze its pathology and immunohistochemistry in comparison with other diseases. Early excision and long-term follow-up are necessary to provide optimal treatment and to better understand the pathological processes of intraductal papilloma.

Intraductal papilloma: atypical presentation

Ductal papillomas have unique papillary features arising from the salivary gland duct system. They comprise three rare benign adenomas, namely, inverted ductal papilloma, sialadenoma papilliferum, and intraductal papilloma. Intraductal papilloma is an extremely rare benign salivary gland tumor that occurs most commonly in the minor salivary glands. Here, we are presenting a case report of intraductal papilloma in an 18-year-old patient.

CD44 expression in intraoral salivary ductal papillomas and oral papillary squamous cell carcinoma

CD44 is a transmembrane adhesion molecule which has been previously shown to be useful in the differentiation of benign papillary lesions from invasive carcinoma in several different areas including sinonasal mucosa and breast tissue. CD44 expression has previously been shown to be lost in invasive carcinoma and retained in benign papillary lesions in both of the above locations. In addition, studies have evaluated oral mucosal lesions for CD44 expression and found a loss with invasive squamous cell carcinoma when compared to normal epithelium, hyperplasia, and squamous papillomas, which stained particularly strongly. To the best of our knowledge, no study has evaluated CD44 expression when comparing salivary ductal papillomas in comparison to oral papillary SCCA. In this study 18 cases of intraductal papilloma were compared to 19 cases of oral papillary SCCA. Within the ductal papilloma group, all cases stained either absent (6%), weakly (33%), or moderately (61%) with 76% expressing the stain diffusely and 24% focally. In comparison, the papillary squamous cell carcinoma cases expressed the CD44 moderately (26%) or strongly (74%) with 100 % showing diffuse staining. Thus, the CD44 expression was contrary to expectation based on previous studies, which we hypothesize is due to the extremely well differentiated nature of papillary SCCA which expressed CD44 staining compatible with levels previously reported with oral squamous papillomas than invasive carcinoma.

Intraductal Papilloma of the Extraglandular Segment of the Stensen Duct

Intraductal papillary neoplasm of major salivary glands is exceedingly rare. Most reported cases have been diagnosed on histopathology; an extensive literature search found no case where a preoperative imaging diagnosis was suspected or established. This report depicts the sonographic diagnosis of intraductal papilloma of the extraglandular segment of the Stensen duct. The sonographic and histological appearances of this rare entity are illustrated.