Sclerosing polycystic adenosis of the parotid gland

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.

Section: Epidemiology and Clinical Featuresmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Sclerosing Polycystic Adenosis of Salivary Glands: A Review with Some Emphasis on Intraductal Epithelial Proliferations

Petersson

2013

“…It has been described as a parotid mass with small cystic areas that are high in signal intensity on T2-weighted MR imaging with enhancement on post-contrast imaging. On ultrasound, it is described as a hypoechogenic, well-circumscribed lesion with microcystic areas [5][6][7]. Grossly, SPA appears as circumscribed, pale, rubbery nodules embedded in normalappearing salivary gland parenchyma [1,2].…”

Section: Diagnosismentioning

confidence: 99%

Sclerosing Polycystic Adenosis

Eliot

Smith

Foss

2011

A 25-year-old female presented with a welldefined, painless mass of 1 year's duration in the right parotid gland. MR imaging revealed a relatively well-circumscribed lesion involving the deep and superficial lobes of the right parotid gland. Histologic examination of the resection resulted in a diagnosis of sclerosing polycystic adenosis, a rare benign salivary gland entity of presumed non-neoplastic origin. The clinical, radiographic, and morphologic features of sclerosing polycystic adenosis are discussed.

“…SPA was first described by Smith et al in 1996 in a series of 9 cases [1]. Since then just over 50 cases in a few larger series and several case reports have been published [2][3][4][5][6][7][8][9][10][11][12][13][14]. The most common site is the parotid gland with less frequent occurrence in the submandibular gland and intraoral minor salivary glands.…”

Section: Introductionmentioning

confidence: 99%

“…The nature of this lesion was initially believed to be reactive/inflammatory in nature [1]. However, using HUMARA-analysis, later investigators have shown that SPA is a clonal process [12] and not infrequently harbors intraductal dysplastic epithelial proliferations including cases where the degree of atypia and structural changes reached that of ductal carcinoma in situ (DCIS) [2,4,5,8,12,13]. To date no case of invasive carcinoma arising in SPA has been reported.…”

Section: Introductionmentioning

confidence: 99%

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

Petersson

Tan

Hwang

2011

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.