Sclerosing polycystic adenosis of the salivary gland: a report of 16 cases

Sclerosing polycystic adenosis of the parotid gland: report of a bifocal, paucicystic variant with ductal carcinoma in situ and pronounced stromal distortion mimicking invasive carcinoma

We present a case (female patient, age 45 years) with a bifocal, paucicystic variant of sclerosing polycystic adenosis of the parotid gland with cribriform ductal carcinoma in situ (DCIS) and pronounced stromal distortion affecting the in situ component to such an extent that it gave a distinct impression of intralesional invasive adenocarcinoma. P63-and calponin-positive myoepithelial cells were present in the periphery of the acini and ducts in the benign component, somewhat discontinuously in the DCIS-component, and even in the periphery of the small irregular atypical cell nests that appeared infiltrative on the haematoxylin and eosin stained sections. Strong cytoplasmic immunoreactivity for GCDFP-15 was detected in the benign component with a variable, patchy and mostly weak positivity in the DCIS. More than 90% of the cells in the DCIS component displayed strong nuclear immunoreactivity for androgen receptors and 10% of the benign ducts showed positivity. Weak to moderate nuclear immunoreactivity for estrogen receptors was seen in 30% of cells in the benign ductal component whereas the DCIS was negative. Occasional cells in the adenosis-component were weakly positive for PR. The proliferative activity (Mib-1/Ki-67) was low (1-2%) in the benign component whereas increased proliferation was seen in the DCIS and in the areas with pseudoinfiltration which also featured atypical mitoses.

Sclerosing polycystic adenosis of the parotid gland: report of one case diagnosed by fine-needle cytology with in situ malignant transformation

Sclerosing polycystic adenosis (SPA) is a rare pathological condition affecting the salivary glands, first described by Smith etal. in 1996. Even though this lesion is being increasingly diagnosed, less than 50 cases have been published in the world literature to date. In line with numerous other pathological analogies between breast and salivary gland lesions, SPA shares with fibrocystic disease of the breast many histopathological features, i.e., fibrosis, oncocytic (apocrine) changes, hyperplasia of ductal and acinar epithelium, cystic dilation of ducts, and, often, atypical epithelial changes. Most of the described cases have followed a benign clinical course, despite the frequent possibility of atypical hyperplasia in more than 50% of the cases and of the more than occasional in situ malignant transformation. In this article, we introduce a new case occurring in the parotid gland of a 57-year-old male showing atypical epithelial hyperplasia and low-grade in situ mucoepidermoid carcinoma. Fine-needle cytology (FNC) was performed on the lesion and, when a diagnosis of SPA was prospected, the variegated cytological features of the obtained sample posed several differential diagnostic problems. The spectrum of pathological lesions entering differential diagnosis comprised sebaceous adenoma, Warthin's tumors with presence of sebaceous remnants, and low-grade mucoepidermoid carcinoma. Histopathological examination disclosed SCA with intraductal neoplastic transformation resembling noninvasive low-grade mucoepidermoid carcinoma. The cytological diagnosis of SPA should be entertained whenever a polymorphous picture is found on FNC samples comprising oncocytic/apocrine changes, sebaceous cells, cystic background, and epithelial hyperplasia with low-grade cytological atypias.

The pathogenic role of Epstein-Barr virus (EBV) in sclerosing polycystic adenosis

Sclerosing polycystic adenosis (SPA) is a pathology of the salivary gland which occurs infrequently and has a controversial etiology. In this study, we investigated the possible roles of HPV and EBV in the pathogenesis of SPA. Archived cases of salivary gland lesions were retrieved, and their diagnoses were re-evaluated; cases that fit the diagnosis of SPA were selected and subjected to Alcian Blue-Periodic Acid Schiff's histochemical staining and immunohistochemical staining for HPV-1, EBV, S-100, and Bcl-2 proteins in addition to the proliferative marker Ki-67. In addition, RNA extracted from formalin-fixed, paraffin-embedded tissues was subjected to RT-PCR to confirm any positive immunohistochemical results. Co-localization of EBV and Bcl-2 in lesional cells was the most striking finding; Ki-67 was expressed in basal cells, while no expression was seen in the adjacent salivary gland cells. Our EBV (+) ve immunostaining results were confirmed by RT-PCR using RNA extracted from paraffin sections. Our results suggest a significant pathogenic role of EBV in SPA. Moreover, they provide new evidence on the neoplastic nature of SPA.

Sclerosing polycystic adenosis of the parotid gland: diagnosis and management

OBJECTIVE

To describe diagnostic and therapeutic management of a rare parotid lesion: sclerosing polycystic adenosis.

PATIENT AND METHOD

We report a case of persistent right intraparotid tumefaction.

RESULTS

A 68-year-old man was referred with a right parotid nodule of 2 years' evolution. Cytology diagnosed pleomorphic adenoma, verified on MRI. Conservative subtotal parotidectomy diagnosed sclerosing polycystic adenosis. Over 1 year's regular follow-up, there were no signs of local recurrence.

CONCLUSION

Sclerosing polycystic adenosis of the parotid gland is a rare and recently described entity presenting several analogies to the much more frequent cystic mastitis. Although benign and well-delimited, it requires complete exeresis of the parotid, due to a non-negligible risk of recurrence.

What's new in the AFIP fascicle on salivary gland tumors: a few highlights from the 4th Series Atlas

After a 12 year interval from the previous fascicle, a new fascicle on Tumors of the Salivary Glands in the new fourth series of the AFIP Atlas of Tumor Pathology was published in 2008. The data, presentation, illustrations, tables, and physical characteristics of the newest fascicle have been updated and improved. There have only been a few alterations and additions to the classification of tumors and tumor-like non-neoplastic conditions of salivary gland. Three of the most significant are discussed in this paper. Sialoblastoma has been reclassified as malignant; inflammatory pseudotumor has been reclassified as neoplastic and re-identified as inflammatory myofibroblastic tumor; and sclerosing polycystic adenosis is a new entity among tumor-like conditions.

New variants of epithelial-myoepithelial carcinoma: oncocytic-sebaceous and apocrine

CONTEXT

Recently described variants of epithelial-myoepithelial carcinoma have not been well characterized but raise a distinct set of differential diagnostic considerations than the classic type.

OBJECTIVE

To report a detailed analysis of oncocytic-sebaceous epithelial-myoepithelial carcinoma (OEMCa) and a similar, but novel, variant, apocrine epithelial-myoepithelial carcinoma (ApEMCa).

DESIGN

Clinical, histologic, and immunophenotypic features of 5 OEMCas and 5 ApEMCas were analyzed. Ultrastructural examination was also performed on 3 OEMCa and 1 ApEMCa tumors.

RESULTS

The mean age for OEMCa (74.4 years; range, 58-82 years) was slightly higher than for ApEMCa (61.6; range, 46-79 years). All tumors arose in the parotid glands and demonstrated a multinodular pattern of growth with an average size of 3.3 cm (range, 2.3-6.5 cm). Available follow-up (n = 6; 3 OEMCas, 3 ApEMCas) shows a favorable course (no evidence of disease; mean, 17.4 months). Both were morphologically similar, but only OEMCa had sebaceous elements. Phosphotungstic acid hematoxylin staining, antimitochondrial antibody immunohistochemistry, and ultrastructural examination confirm the abundance of mitochondria in OEMCa but not in ApEMCa. The ductal component in ApEMCa was distinguished from that of OEMCa by apical snouts, intracytoplasmic vacuoles, nuclear pleomorphism, prominent nucleoli, and androgen receptor immunoreactivity.

CONCLUSIONS

Oncocytic-sebaceous epithelial-myoepithelial carcinoma and ApEMCa should be considered in the differential diagnosis of oncocytic/oncocytoid salivary gland tumors. Oncocytic-sebaceous epithelial-myoepithelial carcinoma morphology may reflect a senescent phenotype, similar to other oncocytic lesions. The ductal component of ApEMCa shares some similarities with salivary duct carcinoma and supports the notion that epithelial-myoepithelial carcinoma can serve as the progenitor tumor for hybrid tumors.

Epithelial proliferation in small ducts of salivary cystadenoma resembling atypical ductal hyperplasia of breast

Salivary gland cystadenomas are cystic neoplasms with diverse architecture and cytology. Cystadenomas may have a considerable intracystic epithelial component, but an epithelial proliferation in small ducts and cysts resembling atypical ductal hyperplasia of breast has not been documented. The patient was a 68-year-old man with a slow growing right submandibular mass. He has no recurrence 13 months after resection. The tumor was polycystic and measured 3.0 x 2.5 x 2.5 cm. The epithelium of the larger cysts was composed of flat, cuboidal, columnar, and apocrine-like cells. Many of the larger cysts showed "Roman bridges", epithelial tufting, and papillae. The smaller cysts and ducts had apocrine-like cells forming secondary glandular lumens. The ductal cells were surrounded by clear myoepithelial cells. Nuclear pleomorphism and hyperchromasia was seen in the apocrine-like cells. Adjacent to the larger cysts, there was an adenomatoid proliferation of small ducts surrounded by myoepithelial cells. No mitotic activity, necrosis, or stromal invasion was identified. The ductal cells were diffusely positive for keratin 7 and androgen receptors with focal expression of keratin 19 and high-molecular weight keratin. S-100, estrogen and progesterone receptors, and BRST-2 were negative in the ductal cells. Recognition of a prominent intraductal epithelial component in cystadenomas is important to avoid a misdiagnosis of cystadenocarcinoma or low-grade salivary duct carcinoma. Cystadenomas join the list of salivary gland lesions with microscopic similarities to primary lesions of the breast.

Sclerosing polycystic adenosis of the buccal mucosa

Sclerosing polycystic adenosis (SPA) is a rare lesion of salivary glands with a striking resemblance to fibrocystic disease of the breast. Most of the 47 reported cases have occurred within the parotid gland, with only a single case being described within the buccal mucosa. We report an additional case of SPA of the buccal mucosa. The exact nature of this entity is unknown, but has up until recently believed to be a pseudoneoplastic reactive and inflammatory sclerosing process. Even though SPA has satisfied the criteria for monoclonality, the debate as to whether SPA represents a true neoplasm or a pseudoneoplastic inflammatory sclerosing process, with low-grade neoplastic potential continues. Awareness of the occurrence of this lesion in both major and minor salivary glands is important to promote its differentiation from other more sinister salivary gland pathology. Cure is effected by localized surgical excision and all reported cases of SPA show an excellent prognosis with no true recurrence or metastasis.

Sialolipoma: Report of two cases and review of the literature

Sialolipoma is a new variant of salivary gland lipoma first described in 2001. We present 2 cases of sialolipoma involving the soft palate and buccal mucosa of 2 female patients. A review of the English language literature revealed 16 cases of sialolipoma reported thus far. We have reviewed the clinicopathologic features of the literature cases and are adding the present 2 cases for a total of 18 cases. To the best of our knowledge, this is the first report of sialolipoma involving the buccal mucosa and the second case in the soft palate. The purpose of this publication is to increase awareness of this recently described variant of lipoma and to address the diagnostic challenges posed both clinically and histopathologically.

Sclerosing polycystic adenosis of minor salivary glands: report of three cases and review of the literature

Sclerosing polycystic adenosis (SPCA) of the salivary gland is a rarely encountered lesion of uncertain pathogenesis that shares histologic features with sclerosing adenosis and fibrocystic disease of the mammary gland. To date, fewer than 40 cases of SPCA have been reported in the literature; all but one have arisen in the major salivary glands. We report 3 cases of SPCA involving minor salivary glands and discuss the characteristic histopathologic features of SPCA , which include a combination of fibrosis, tubuloacinar proliferation, and cystic change with retention of a somewhat lobular architecture. We also provide a review of contemporary relevant literature. Given that SPCA has been mistaken for malignant salivary gland neoplasia, a familiarity with the entity is critical. Three new cases of SPCA involving minor glands are added to 1 existing case in the literature to raise awareness of the lesion and to reduce the likelihood of misdiagnosis.

Fine-needle aspiration biopsy findings in sclerosing polycystic adenosis of the parotid gland

Sclerosing polycystic adenosis (SPA) is a recently described, rare lesion of the salivary gland analogous to fibrocystic disease of the breast. Recognition of this benign entity is important since the differential diagnosis includes other more common benign and malignant salivary gland neoplasms, particularly mucoepidermoid carcinoma and tumors with cystic and oncocytic features. While the histomorphology of SPA is well documented, there is only one other cytologic description of SPA in the English-language literature. Here we describe the fine-needle aspiration biopsy findings in a case of SPA of the parotid gland in an 84-year-old woman. The aspirate was characterized by flat cohesive sheets of epithelial cells with moderate amounts of finely granular oncocytic cytoplasm and enlarged round nuclei with indistinct nucleoli. Some epithelial groups formed glandular structures with lumens, and the background contained small amounts of delicate mucoproteinaceous material. Occasional markedly vacuolated cells were present as well as many cells with apocrine change manifested by well-defined apical snouting. Familiarity with the cytomorphologic features of SPA, including its characteristic apocrine changes, is important for distinguishing it from other more clinically significant salivary gland lesions.

Sclerosing mucoepidermoid carcinoma of the salivary glands

Mucoepidermoid carcinoma (MEC) comprises approximately 30% of all salivary gland malignancies, making it the most common malignant tumor of the salivary glands. Multiple histologic variants with a wide range of differentiation have been described. Sclerosing MEC (SMEC) is a rare subtype that may be misdiagnosed as a benign reactive condition or low-grade non-SMEC malignancy. We report 4 cases of SMEC and evaluated them with Her-2/neu and MIB-1 to determine whether an association exists between the histologic grade and immunohistochemical findings. In 3 cases, histologic examination demonstrated relatively well-circumscribed, nonencapsulated tumors composed of extensive central sclerosis with keloid-like stroma and scattered epithelial islands of low-grade MEC. In the fourth case, the tumor showed similar sclerotic stroma; but the epithelial component was of intermediate grade. In all 4 cases, eosinophils and neutrophils were part of the inflammatory infiltrate; and the edges were surrounded by lymphoid tissue, with germinal center formation and residual epithelial islands. A Mayer mucicarmine stain revealed abundant intracytoplasmic mucin. We found MIB-1 labeling indices of 5% or less in cases 1, 2, and 3 and 12% in case 4, suggesting an association between MIB-1 index and tumor grade. The tumors were negative for Her-2/neu in all 4 cases. The latter seems to bear no relationship to tumor grade.

Advances in salivary gland pathology

This review summarizes the new findings on salivary gland pathology under the following categories: immunohistochemistry; molecular genetics; newly recognized tumour types; known tumour entities with new findings; and progression of salivary gland tumours. In the application of immunohistochemistry, CD117 can aid in highlighting the luminal cell component of various salivary gland tumours, whereas p63 or maspin can aid in highlighting the abluminal cell component. A high Ki67 index remains the most useful marker to predict adverse outcome in salivary gland carcinoma. Specific chromosomal translocations are recognized in pleomorphic adenoma (with translocation involving PLGA1 or HMGA2 gene) and mucoepidermoid carcinoma (with MECT1-MAML2 gene fusion). Newly recognized entities include: sclerosing polycystic adenosis (with recent molecular evidence supporting its neoplastic nature), sclerosing mucoepidermoid carcinoma with eosinophilia, keratocystoma, adenoma with additional stromal component (lymphadenoma, lipoadenoma and adenofibroma), cribriform adenocarcinoma of the tongue and signet ring adenocarcinoma of minor salivary gland. Known tumour entities with new findings include: salivary duct carcinoma (with newly recognized mucinous, micropapillary and sarcomatoid variants), intraductal carcinoma (with controversies in terminology), mucoepidermoid carcinoma (with newly proposed grading parameters and oncocytic variant), epithelial-myoepithelial carcinoma (with newly recognized morphological variants), small cell carcinoma (with most cases being related to Merkel cell carcinoma), extranodal marginal zone B-cell lymphoma (with specific chromosomal translocation) and chronic sclerosing sialadenitis (being a component of IgG4-related sclerosing disease). Progression of salivary gland tumours can take the form of malignant transformation of a benign tumour, progression from low-grade to high-grade carcinoma, dedifferentiation, or stromal invasion of an in situ carcinoma.

Clonal nature of sclerosing polycystic adenosis of salivary glands demonstrated by using the polymorphism of the human androgen receptor (HUMARA) locus as a marker

Sclerosing polycystic adenosis (SPA) is a recently described, rare lesion of the salivary glands that bears a resemblance to epithelial proliferative lesions of the breast. The true nature of the lesion is unknown, but up to now it has been generally believed to represent a pseudoneoplastic sclerosing and inflammatory process. However, local recurrence developed in about one-third of the cases. Superimposed dysplastic changes ranging from low-grade dysplasia to carcinoma in situ were described in SPA. Although no metastases-related and/or disease-related patient deaths were documented, these clinical and histopathologic features raise the possibility that SPA might represent a neoplastic lesion. Polymorphism of the human androgen receptor locus is most frequently used to assess whether the pattern of X-chromosome inactivation is random or nonrandom, the latter strongly indicating clonality. In this study, the assay was applied to tissue from 12 examples of SPA. Three cases (males) were noninformative and 3 cases (females) could not be analyzed owing to poor quality of DNA, but all the remaining 6 lesions satisfied the criteria for monoclonality. We therefore conclude that the findings in the present study are further supporting evidence that SPA is a neoplasm, and not just a reactive process.