Sclerosing polycystic adenosis of parotid gland: a cytological diagnostic dilemma

Sclerosing Polycystic Adenosis Arising in the Parotid Gland Without PI3K Pathway Mutations

A 15-year-old old Japanese male with a 2-month history of swelling of his left subauricular area was admitted to our department. A thumb-sized, hard mass with mild tenderness was palpated on the left parotid gland. Ultrasonography revealed a well-circumscribed, hypoechoic mass exhibiting heterogeneity in the left parotid gland measuring 1.7 × 1.5 × 1.3 cm. Computed tomography scan revealed a well-circumscribed, solid mass exhibiting slight peripheral enhancement in the left parotid gland. Magnetic resonance imaging revealed a hypointense mass in the left parotid gland on both T1- and T2-weighted images. Clinicoradiologic findings suggested a benign or low-grade malignant parotid tumor. The patient underwent left superficial parotidectomy with adequate safety margins. The facial nerve was identified and preserved. Neither facial paralysis nor tumor recurrence was observed as of 1 year postoperatively. Histologically, the nodule consisted of a vaguely nodular arrangement of variably sized ducts and acini in a hyalinized fibrous background with focal myxoid changes. The ductal/acinar component exhibited a bilayered arrangement of cuboidal luminal and flattened abluminal cells exhibiting a variety of epithelial proliferative patterns, including micropapillary and cribriform. Areas of oncocyte-like changes with intracellular coarse eosinophilic granules, apocrine-like feature, foamy/vacuolated changes, and clear cells were noted in the proliferating epithelium. Immunohistologically, the luminal cells were positive for gross cystic disease fluid protein-15. The Ki-67 labeling index was 2-3%. The histologic features and immunohistologic profile were consistent with sclerosing polycystic adenosis. Targeted next-generation sequencing of 160 cancer-related genes using the surgical specimen revealed no mutations, including known significant mutations in PTEN, PIK3CA, or PIK3R1.

Juvenile sclerosing polycystic adenosis cytologically mimicking Warthin tumor

Sclerosing polycystic adenosis (SPA) is a rare salivary gland disease. Histologically it resembles a low-grade ductal carcinoma in situ or sclerosing adenosis of the breast, characterized by lobular proliferation of ducts with apocrine cellular features surrounded by fibrosclerotic stroma. Although SPA is typically benign, recurrence is not uncommon, and cases with a malignant component have been documented. Thus, complete excision is desirable but preoperative diagnosis is challenging. A 12-year-old boy presented with a painless mass in the right neck. We identified a well-demarcated mass in the right parotid region measuring approximately 2 cm using cervical echography and magnetic resonance (MR) imaging. Fine-needle aspiration (FNA) revealed two cell types. There were loosely cohesive clusters of polymorphic epithelioid cells with irregular nuclei and abundant vacuolated cytoplasm containing zymogen granules. Some of these cells were binuclear. The other cell types represented normal ductal cells. The original cytological diagnosis was Warthin tumor. Right parotidectomy was performed. Histologically, we observed proliferation of ducts with granular, vacuolated, zymogen granules, and apocrine-like features in the cytoplasm with hyalinizing sclerotic stroma and some binuclear cells. Four years after parotidectomy, there has been no recurrence or malignant transformation.Cytological diagnosis of SPA is challenging on FNA specimens since SPA is a very rare entity of the salivary gland that can mimic other salivary gland neoplasms. A mixture of apocrine-like cells and sebaceous-like cells, nuclear pleomorphism, and zymogen granules can help to diagnose this rare lesion during the initial cytological diagnosis.

Newly described salivary gland tumors

This review concentrates on three salivary gland tumors that have been accepted in the recent literature as new neoplastic entities: mammary analog secretory carcinoma (MASC), sclerosing polycystic adenoma (SPA) and cribriform adenocarcinoma of tongue and other minor salivary glands (CAMSGs). MASC is a distinctive low-grade malignant salivary cancer that harbors a characteristic chromosomal translocation, t(12;15) (p13;q25) resulting in an ETV6-NTRK3 fusion. SPA is a rare lesion often mistaken histologically for low-grade salivary carcinoma. Previously thought to be a reactive fibroinflammatory process, but recent evidence of clonality, recurrences in up 30%, and dysplastic foci suggest it may be truly neoplastic. CAMSG is a distinct tumor entity that differs from polymorphous low-grade adenocarcinoma (PLGA) by location (ie, most often arising on the tongue), by prominent nuclear clearing, alterations of the PRKD gene family and clinical behavior with frequent metastases at the time of presentation of the primary tumor. Early metastatic disease seen in most cases of CAMSG associated with indolent behavior makes it a unique neoplasm among all low-grade salivary gland tumors. Salivary glands may give rise to a wide spectrum of different tumors. They are often diagnostically challenging as morphological features often overlap between different entities. Although conventional morphology in combination with immunohistochemical findings still provide the most important clues for diagnosis, recent advances in molecular pathology offer new diagnostic tools in investigating the differential diagnosis, as well as providing potentially valuable prognostic indicators. In the last two decades, several new salivary gland tumor entities have been described, namely MASC, SPA and CAMSGs.

Sclerosing Polycystic Adenosis of the Parotid Gland: A Systematic Review and Report of 2 New Cases

PURPOSE

We sought to evaluate clinical-epidemiologic aspects, pathologic characteristics, and treatment of sclerosing polycystic adenosis (SPA) of the parotid gland and to report 2 new cases.

MATERIALS AND METHODS

We conducted a systematic review following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for studies published in or before June 2016. The inclusion criteria were as follows: final diagnosis of SPA affecting the parotid gland and articles published in Spanish or English. The exclusion criteria were as follows: unclear diagnosis after pathologic analysis and patients affected by other conditions in the major salivary glands. We added 2 new cases.

RESULTS

Our review ultimately included 21 articles and 45 cases. The mean patient age was 41 years (range, 7-84 years). The female-to-male ratio was 2:1. In all patients the tumor showed progressive growth. The evolution range was 7 days to 11 years. In 17.7% of cases, the tumor was associated with pain. The average tumor size was 30.3 mm (range, 12-60 mm). Fine needle aspiration biopsy (FNAB) was unable to diagnose 30 cases. Benign tumors comprised 58% of tumors (18), whereas malignancy was present in 25.8% (8). Thirty-five tumors were well circumscribed. There were 8 multinodular or lobed cases. The tumor was described as encapsulated in 1 case, partially encapsulated or pseudo-encapsulated in 16, and not encapsulated in 12. Five cases showed different degrees of degenerative changes, ranging from dysplasia to invasive carcinoma. All cases underwent surgical treatment. Superficial parotidectomy with preservation of the facial nerve was performed in 22 cases (61.1%), total parotidectomy in 8 (22.2%), and tumor enucleation in 6 (16.6%). The mean follow-up period was 51.5 months (range, 5-276 months). Of documented cases, 74.2% had 2 or more years of follow-up. Recurrences occurred in 6 cases (16.6%).

CONCLUSIONS

We consider SPA a benign tumor with progressive growth, which is occasionally painful. It occurs around age 40 years and occurs more often in female patients. Fine needle aspiration biopsy does not provide an adequate preoperative diagnosis. Recurrences are infrequent. Follow-up should be customized according to the pathologic findings. Malignant transformation may occur. Superficial parotidectomy with facial nerve preservation is the treatment of choice.

Surgical Treatment of Rare Sclerosing Polycystic Adenosis of the Deep Parotid Gland

We experienced a rare case of sclerosing polycystic adenosis (SPA) arising in a parotid gland. A 33-year-old man who underwent unspecified surgery for a lesion in the left parotid gland 23 years ago presented with a lesion on the same site. Computed tomography scan revealed an encapsulated 3 × 2 cm lesion. Intraoperative findings showed that the tumor was embedded deep in the parotid gland. Marginal tumor excision was performed to preserve the facial nerve. Histopathological and immunohistochemical findings led to the final diagnosis of SPA. The surgery was not associated with any other complications. To date, 28 months after surgery, recurrence has not been observed. The treatment protocol of SPA has not yet been established. To make plastic surgeons familiar with this disease, we describe this case, which was successfully treated without any complications.

Authors attain comparable or slightly higher rates of citation publishing in an open access journal (CytoJournal) compared to traditional cytopathology journals - A five year (2007-2011) experience

BACKGROUND

The era of Open Access (OA) publication, a platform which serves to better disseminate scientific knowledge, is upon us, as more OA journals are in existence than ever before. The idea that peer-reviewed OA publication leads to higher rates of citation has been put forth and shown to be true in several publications. This is a significant benefit to authors and is in addition to another relatively less obvious but highly critical component of the OA charter, i.e. retention of the copyright by the authors in the public domain. In this study, we analyzed the citation rates of OA and traditional non-OA publications specifically for authors in the field of cytopathology.

DESIGN

We compared the citation patterns for authors who had published in both OA and traditional non-OA peer-reviewed, scientific, cytopathology journals. Citations in an OA publication (CytoJournal) were analyzed comparatively with traditional non-OA cytopathology journals (Acta Cytologica, Cancer Cytopathology, Cytopathology, and Diagnostic Cytopathology) using the data from web of science citation analysis site (based on which the impact factors (IF) are calculated). After comparing citations per publication, as well as a time adjusted citation quotient (which takes into account the time since publication), we also analyzed the statistics after excluding the data for meeting abstracts.

RESULTS

Total 28 authors published 314 publications as articles and meeting abstracts (25 authors after excluding the abstracts). The rate of citation and time adjusted citation quotient were higher for OA in the group where abstracts were included (P < 0.05 for both). The rates were also slightly higher for OA than non-OA when the meeting abstracts were excluded, but the difference was statistically insignificant (P = 0.57 and P = 0.45).

CONCLUSION

We observed that for the same author, the publications in the OA journal attained a higher rate of citation than the publications in the traditional non-OA journals in the field of cytopathology over a 5 year period (2007-2011). However, this increase was statistically insignificant if the meeting abstracts were excluded from the analysis. Overall, the rates of citation for OA and non-OA were slightly higher to comparable.

Sclerosing polycystic adenosis of parotid gland: a unique report of two cases occurring in two sisters

Sclerosing polycystic adenosis (SPA) of salivary glands is a tumorous lesion of salivary glands, with clinical presentation of a slow-growing mass characterized by a combination of histological features, some of which are reminiscent of mammary fibrocystic disease. SPA is mostly unifocal, but rarely may be multifocal and/or bilateral. Recurrences have been reported in up to 19% of cases. Although originally considered pseudoneoplastic, the occurrence of "dysplasia" and carcinoma in situ of ductal epithelium, and recent evidence of clonality suggest a possible neoplastic nature. Herein we describe, for the first time, two cases of SPA in two sisters (7 and 33 years old). The younger patient experienced multiple recurrences. This is the first report of familial occurrence of SPA, suggesting a possible genetic background.

Sclerosing polycystic adenosis of salivary glands: a review with some emphasis on intraductal epithelial proliferations

Sclerosing polycystic adenosis (SPA) is a rare condition of salivary glands. The most common site is the parotid gland (80 % of cases). SPA shows no gender predilection and occurs over a wide age spectrum (9-84 years). SPA is mostly unifocal, but may rarely be multifocal. Histologically, SPA are sharply circumscribed mostly unencapsulated lesions composed of acinar and ductal components with variable cytomorphological characteristics, including foamy, vacuolated, apocrine, mucous, clear/ballooned, squamous, columnar and oncocyte-like cells. Characteristic for SPA is the presence of large acinar cells with abundant eosinophilic cytoplasmic granules. The stroma is densely collagenized, frequently harbouring a variably intense chronic inflammatory infiltrate and may contain fat. Rarely the stroma is myxoid. Some degree of intraductal epithelial proliferations have been reported in at least 50 % of cases. The proportion of cases with epithelial proliferations that fulfill criteria for high-grade ductal carcinoma in-situ is <10 %. Immunohistochemically, both ductal and acinar cells are positive for broad spectrum cytokeratins. There is variable immunoreactivity for epithelial membrane antigen and S-100 protein. CEA, p53 and HER2 is reportedly negative. Gross cystic disease fluid protein-15 is strongly expressed in the acinar component. There is consistent but variable expression of estrogen and progesterone receptors. The proliferative index (Ki-67) is low (1-2 %) in the benign (acinar and ductal) components. Using HUMARA methodology (non-random inactivation of X-chromosomes), six cases with atypical epithelial proliferations have been shown to be clonal processes. Recurrences have been reported in up to 19 % of 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.