Sialadenoma papilliferum: an immunohistochemical study of five cases

Case Report: Papillary Lesions at the Mouth Floor May Mimic Sialadenoma Papilliferum

Salivary gland tumor Sialadenoma papilliferum (SialP) clinically resembles papillary epithelial lesions, such as squamous papilloma (SqP) or verrucous leukoplakia. Pathological sampling including an adequate depth of both the mucosa and submucosa layer is required for discrimination between the diseases. Though ductal proliferation in the submucosa is characteristic in SialP, papillary lesions arising at the mouth floor, specifically near the ductal orifice, are more problematic. Salivary gland ductal ectasia, along with the overlying papillary hyperplasia, may mimic the biphasic tumorous growth pattern of SialP, making discrimination extremely difficult. Further cellular dysplasia in the papillary mucosal lesion raises the possibility of malignant transformation in a known benign lesion, SialP. Herein, we present a case of SqP at the mouth floor which mimicked both clinical and pathological features of SialP and compared it with a definite case of SialP. Moreover, we discuss major differential points that clinicians and pathologists should consider during diagnosis of oral papillary lesions arising near the salivary glands.

Sialadenoma Papilliferum of the Bronchus: An Unrecognized Bronchial Counterpart of the Salivary Gland Tumor With Frequent BRAF V600E Mutations

Sialadenoma papilliferum (SP) is a rare benign tumor of the salivary glands, and only 3 unequivocal cases of SP arising in the bronchus have been reported. We herein describe the histomorphologic and molecular features of 4 bronchial SP cases and discuss the differential diagnosis of this entity and the relationship with its clinicopathologic mimics, in particular, glandular papilloma and mixed squamous cell and glandular papilloma (GP/MP). We encountered 2 male and 2 female patients with bronchial SP (mean: 66.8 y old). All 4 tumors arose in the central bronchus and were characterized by a combination of surface exophytic endobronchial papillary proliferation and a submucosal multicystic component with complex architecture. The neoplastic epithelium consisted predominantly of nonciliated stratified columnar cells with ciliated, squamous, and mucinous cells present focally. While 2 tumors (50%) harbored a BRAF V600E mutation by molecular and immunohistochemical analysis, similar to GP/MP, no KRAS, HRAS, AKT1, or PIK3CA mutations were detected in any of the cases. Two patients were treated with limited resection, while 2 patients underwent lobectomy based on the diagnosis of adenocarcinoma or possible squamous cell carcinoma in situ in the preoperative biopsy. All survived without recurrence or metastasis for 23 to 122 months after treatment. SP can develop in the central bronchus as the bronchial counterpart of the salivary gland tumor and should be considered in the differential diagnosis of endobronchial tumors. In addition, some histologic resemblance and frequent BRAF V600E mutation raise the possibility of SP and GP/MP being on the same disease spectrum.

Sialadenoma papilliferum: clinicopathologic, Immunohistochemical, molecular analyses of new five cases and review of the literature

Background

Sialadenoma papilliferum (SP) is an extremely rare benign neoplasm of salivary glands. To explore and define the clinicopathological features of SP, we retrospectively analyzed 89 cases previously reported and five new cases.

Methods

The clinical features, histopathology, immunohistochemistry and molecular analysis of our cases were further performed and the related literatures were reviewed and analyzed.

Results

Combining 89 cases from the literature with our cases, the hard palate was the most common locations for SP. However, two of our cases were rarely located in the esophageal mucosa. Among all cases, the male gender was more affected, with the average age and median age of 61.8 and 62 years, respectively. Conventional histomorphologically, SP was characterized by complex papillary structures with a biphasic growth pattern of exophytic squamous component and endophytic glandular component. The glandular structures were lined by a double layer of epithelium composed of flattened or cuboidal basal cells and a cuboidal or columnar luminal cells formed papillary infoldings into the ductal lumina. Immunohistochemically, the luminal epithelial configurations showed strong expression of CK7 along the luminal cell membrane, while the basal myoepithelia displayed strong nuclear p63 expression. In both the glandular and squamous tumour components showed BRAF V600E-positive immunostaining and BRAF V600E mutation.

Conclusion

For the first time, we have comprehensively aggregated and analyzed 90 cases sialadenoma papilliferum from almost all previous publications, and further explored the clinicopathological features of SP; concordantly, this study demonstrated that SP shows a papillomatous growth pattern with exophytic and endophytic proliferation of ductal epithelium composed of double-layered cells harboring BRAF V600E mutation. Additionly, adequate treatment for SP is surgical excision, with a favorable prognosis in patients.

Sialadenoma Papilliferum

Sialadenoma papilliferum (SP) is a rare, benign salivary gland neoplasm sharing similar histopathologic features and harboring the same genetic alterations, BRAF V600E or HRAS mutations, with syringocystadenoma papilliferum. SP most commonly occurs in the hard palate and in older adults. Clinically, SP is most likely to be diagnosed as a squamous papilloma. Microscopically, SP shows an exophytic papillary epithelial proliferation and a contiguously endophytic ductal proliferation. Two distinct subtypes are identified: classic SP and oncocytic SP. Conservative surgical treatment seems to be adequate with a low recurrence. SOX10 immunohistochemistry and BRAF analysis may be useful in differential diagnosis.

Sialadenoma papilliferum: Bibliometric analysis

Background

Sialadenoma papilliferum is a benign rare condition of salivary glands showing a characteristic papillary growth of the ductal epithelium that ends up being confused with more frequent lesions of the oral cavity. Objectives: To perform a bibliometric analysis of all articles about Sialadenoma papilliferum in the oral cavity and to add a singular case report of Sialadenoma in the lower lip.

Material and Methods

A total of 36 publications referring to Sialadenoma papilliferum in the oral cavity from the PubMed platform was reviewed. The specific data were collected, and a bibliometric analysis was performed using Microsoft Excel. The results obtained were then compared with this new case report.

Results

The people most affected with sialadenoma were white males at the average age of 56. The lesion was asymptomatic, usually white or red, with an average size of 1.4 cm, and the palate was by far the most affected site. The majority of the lesions were excised, and only two cases indicated recurrence.

Conclusions

With surgical removal, Sialadenoma papilliferum has a favorable prognosis and no further treatment is required. Due to few recorded cases of recurrence, a long follow-up period is recommended to ensure that the lesion does not redevelop.

Key words:Sialadenoma papilliferum, salivary gland, oral cavity, bibliometric analysis.

Salivary Sialadenoma Papilliferum Consists of Two Morphologically, Immunophenotypically, and Genetically Distinct Subtypes

Papillary salivary gland neoplasms are rare tumors usually arising in the minor salivary glands of the oral cavity. Their classification has been historically confusing due to overlapping histologic features, but molecular analysis may clarify these entities. Sialadenoma papilliferum (SP) is a peculiar member of this group that demonstrates both an endophytic ductal and an exophytic squamous component. SP closely resembles syringocystadenoma papilliferum of the skin, a tumor which has recently been shown to harbor BRAF V600E or HRAS mutations. We sought to perform histologic and immunophenotypic analysis of a group of SP, along with BRAF and HRAS mutational analysis. We collected 13 SP cases from 7 females and 6 males ranging from 2 to 91 years (mean 62.8). Five exophytic ductal papillomas were also analyzed as controls. Histological analysis was performed along with immunohistochemistry for CK7, p63, and SOX10. BRAF VE1 immunohistochemistry was done in all tumors, and BRAF V600E and HRAS Sanger sequencing was successfully performed in all but two cases. Histologic analysis revealed that SP consisted not only of classic SP (9 of 13 cases) but also an oncocytic variant (4 of 13 cases) characterized by a glandular component that uniformly exhibited abundant granular cytoplasm and prominent nucleoli. By immunohistochemistry, all SP demonstrated luminal CK7 and basal p63 expression, but SOX10 was expressed only in conventional SP (9 of 9 cases). BRAF VE1 immunohistochemistry was positive in 9 of 9 conventional SP but 0 of 4 oncocytic SP; staining was present in both the exophytic and endophytic components. BRAF V600E mutational status was confirmed by Sanger sequencing in 11 cases (7 conventional and 4 oncocytic). The exophytic ductal papillomas were negative for BRAF mutations, and all tumors tested were negative for HRAS mutations. In summary, we demonstrated that SP consists of two variants: (1) conventional SP which is SOX10-positive and harbors BRAF V600E mutations similar to syringocystadenoma papilliferum of the skin; and (2) an oncocytic variant which is SOX10-negative and negative for BRAF mutations. We also demonstrated that both the endophytic glandular component and exophytic squamous components of conventional SP harbor BRAF V600E mutations and are therefore neoplastic.

Sialadenoma Papilliferum: Analysis of Seven New Cases and Review of the Literature

Sialadenoma papilliferum (SP) is a rare benign salivary gland neoplasm that comprises from 0.4 to 1.2% of all salivary gland tumors. The tumor is so named because of its microscopic resemblance to the syringocystadenoma papilliferum, an uncommon benign tumor of sweat gland origin. The purpose of this paper is to report the clinical and microscopic features of seven new cases of SP and combine them with cases previously reported in the English language literature to further define this unusual lesion. Combining our cases with acceptable cases from the literature, the palate (especially the hard palate) was the most common site, with 80% of the cases occurring in this location. Other locations in decreasing order were buccal mucosa, upper lip, retromolar pad, and parotid gland. Age at diagnosis ranged from 18 to 87 years with a peak in the 6th decade and an average age of 56.4 years. Microscopically, the lesions demonstrated a papillary surface morphology, and the papillary projections varied from long and pointed to short and blunted. The supporting connective tissue contained a variable number of convoluted ductal structures, which often fused with the overlying surface epithelium. The ductal structures exhibited papillary infoldings and were lined by a double layer of epithelium consisting of basal cell layer and a luminal layer of cuboidal-to-columnar ductal cells. Immunohistochemical reactivity with p63 and p40 indicated that the basal cell layer was comprised predominantly of neoplastic myoepithelial cells. The luminal cells were immunoreactive with epithelial membrane antigen characteristic of ductal cell differentiation. Conservative surgical treatment was accomplished in most cases and appears to be adequate treatment as only two recurrences were documented. Several case reports of purported malignant transformation in SP have been reported in the literature, but in our opinion, there is insufficient evidence in the publications to unequivocally determine whether any of the malignancies truly originated within a pre-existing SP.

Sialadenoma papilliferum in a young patient: a case report and review of the literature

Sialadenoma papilliferum is a rare exophytic tumor of salivary gland origin, accounting for less than 1% of minor salivary gland tumors. It usually occurs in males older than 50 years as a painless papillary intraoral lesion. An 18-year-old male patient presented with an exophytic intraoral lesion present for approximately 12 years. The tumor was excised with a clinical diagnosis of infected hemangioma. However, histopathological diagnosis was consistent with sialadenoma papilliferum. The patient was followed up at regular intervals and no evidence of recurrence was noted. Our patient, aged 18 years, with tumor lasting for 12 years becomes the youngest case of intraoral sialadenoma papilliferum yet reported. This case highlights the importance of keeping sialadenoma papilliferum as a differential diagnosis of an intraoral exophytic proliferative lesion even in a young patient.

[Rare sialadenoma papilliferum in the hard palate: case report and survey of the literature]

Sialadenoma papilliferum is a rare tumour of the salivary glands that usually occurs in the oral cavity. Following the course of the salivary glands of the oral mucosa, the hard and soft palate are the most common locations of this tumor. In the international literature, only a few case reports about this entity can be found. We present a 63-year-old patient with a sialadenoma papilliferum accidentally found during diagnostic procedures for progredient dysphagia. Suffering from infrabifurcal cancer of the oesophagus, the patient had undergone partial oesophagectomy 1 year before. Histological verification was performed with a tumor biopsy at the border of hard and soft palate, on the right side. This case is compared with 39 further cases reported in the literature. The therapy of choice is resection of the tumor. Because of the high frequency of recurrence, in sano resection should be planned.

Malignant transformation of sialadenoma papilliferum of the palate: a case report

We report a case of a 79-year-old woman with an unusual salivary gland tumor that developed at the junction between the soft and hard palates. The tumor consisted of sialadenoma papilliferum (SP) with areas of an epithelial-myoepithelial carcinoma (EMC) component and a high-grade carcinoma component. There were also transitional regions among the SP, the EMC and the high-grade carcinoma components. The high-grade carcinoma component, which was similar to invasive micropapillary carcinoma of the breast, infiltrated into the right parapharyngeal space and metastasized to the lungs and cervical vertebrae. The high-grade carcinoma cells were positively immunostained for p53 protein. SP has been considered to be a benign tumor with exceptionally good prognosis, and, to the best of our knowledge, there has never been a confirmed case of malignant SP. This is the first report of SP with a definite malignant component.

Sialadenoma papilliferum: immunohistochemical study

Sialadenoma papilliferum (SP) is a rare benign tumour of salivary gland origin, which has been included among the ductal papillomas in the latest classification of tumours by the World Health Organisation. Two SP from the minor salivary gland of the palate of middle age patients were presented and studied by immunohistochemical. Our results showed presence of cytokeratins (CKs) 13, 14, 7, 8, 19 and absence of vimentin and smooth muscle actin. This immunoprofile is similar to the excretory duct of salivary gland.

Sialadenoma papilliferum of the hard palate: report of 2 cases and immunohistochemical evaluation

This study reports on the clinical and histologic features of 2 previously unreported cases of sialadenoma papilliferum. Immunohistochemical analysis of one of the cases demonstrated that the ductal cell component shows both epithelial and myoepithelial differentiation.

Ductal papillomas of salivary gland origin: A report of 19 cases and a review of the literature

The term ductal papilloma is used to identify a group of 3 rare benign papillary salivary gland tumors known as inverted ductal papilloma, sialadenoma papilliferum, and intraductal papilloma. They represent adenomas with unique papillary features and arise from the salivary gland duct system. We describe the clinical and microscopic features of 19 new cases of ductal papillomas and combine them with 116 cases previously published in the English-language medical literature. These 19 cases were composed of 13 inverted ductal papillomas, 3 sialadenoma papilliferums, and 3 intraductal papillomas. Collectively, these 19 ductal papillomas occurred most commonly in the sixth to eighth decade of life, with an average patient age of 54 years. Men predominated 1.37:1. The sialadenoma papilliferums presented as papillary lesions clinically with all 3 misinterpreted as squamous papillomas by the surgeons. The inverted ductal papillomas and intraductal papillomas appeared as submucosal nodules. The lip and the palate were the most common locations for inverted ductal papilloma and sialadenoma papilliferum, respectively. The sites for the 3 intraductal papillomas were the parotid papilla of the Stensen's duct, the upper lip, and the buccal mucosa. With light microscopy, inverted ductal papillomas appeared to arise from the excretory ducts near the mucosal surface, whereas intraductal papillomas appeared to arise from the excretory ducts at a deeper level. Sialadenoma papilliferum had a more complex histology, with a biphasic growth pattern of exophytic papillary and endophytic components. All 19 cases were treated by surgical excision. Follow-up information was available in only 2 cases, both inverted ductal papillomas. Neither case recurred during a 20-year period. Sialadenoma papilliferum, with a literature-derived recurrence rate of 10% to 15%, seems to assert a more significant biological behavior than inverted ductal papilloma and intraductal papilloma. Our findings justify the separation of these 3 entities based on clinical and histologic parameters. They are tumors of adulthood and, in addition, have in common their relationship to the excretory duct system, their anatomical distribution, and their general behavior.

Sialadenoma papilliferum of the palate: case report and literature review

Sialadenoma papilliferum (SP) is a rare tumor of salivary gland ducts which bears a strong histologic resemblance to the more common syringocystadenoma papilliferum (SCAP). We report a case occurring on the palate of a 50-year-old man, and review the clinical and histologic features of this tumor. Because of the histologic similarities between these two tumors and squamous papillomas, polymerase chain reaction (PCR) for human papilloma virus (HPV) DNA was performed on this tumor and on two cases of SCAP, with negative results. To our knowledge, this is the first case report of SP in the dermatopathology literature.