Sclerosing polycystic adenosis of the parotid gland: diagnosis and management

Sclerosing polycystic adenosis arising in the parotid gland with trismus: a case report and literature review

Sclerosing polycystic adenosis (SPA) is a rare, asymptomatic disease that occurs mainly in the salivary glands. We report the case of a 51-year-old man who presented with trismus and pain upon mouth opening. Magnetic resonance imaging revealed a 2-cm mass located in the anterior portion of the left parotid gland. SPA was diagnosed based on histopathological examination of the surgical specimen. In pathologic findings, there was a well-circumscribed multicystic nodule in the parenchyma. Dense fibrosis and chronic non-specific inflammatory cells were observed in the stroma. In 13 previous reports on SPA, the most preferred treatment was superficial or total parotidectomy. This report suggests that simple excision of SPA preserves facial nerve function and facial volume.

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.

Imaging of Inflammatory Disorders of Salivary Glands

Sialadenitis is among the most common conditions that affect the salivary glands. Inflammation of the salivary glands occurs as the end result of a variety of pathologic conditions, including infectious, autoimmune, and idiopathic causes. Clinically, inflammation of the salivary gland causes pain and localized swelling. The presentation may be acute or chronic, and can be recurrent. Because there is significant overlap of underlying disease mechanisms and clinical presentations, radiologic evaluation often plays a significant role in evaluation. This article is a brief review of sialadenitis, including disease mechanisms, causes, and the practical imaging of the salivary glands.

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.

Sclerosing Polycystic Adenosis: A Rare Tumor of the Salivary Glands

CASE PRESENTATION

A 74-year-old woman presented to the Head and Neck Surgery clinic with a 4-year history of a slowly growing, painful, left-sided neck mass in the tail of the parotid gland. Fine-needle aspiration suggested well-differentiated adenocarcinoma.

DISCUSSION AND RESULTS

The patient underwent a superficial parotidectomy and super-selective neck dissection (level 2). Pathology revealed a tumor consistent with sclerosing polycystic adenosis.

CONCLUSION

Sclerosing polycystic adenosis is a rare inflammatory process that causes fibrocystic changes in the salivary gland. Apocrine-like metaplasia and epithelial atypia are common pathologic features. To our knowledge, a total of 51 cases have been described in the English-language literature.

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.

A unique case of sclerosing polycystic adenosis of the sinonasal tract

Sclerosing polycystic adenosis is an extremely uncommon, recently described, sclerosing lesion of the salivary glands that appears histologically similar to fibrocystic changes of the breast. The key histopathologic features of sclerosing polycystic adenosis include lobular proliferation of ductal and acinar elements, cystically dilated ducts exhibiting frequent apocrine and sebaceous metaplasia, eosinophilic intracytoplasmic granules within some acinar-type cells, intraductal epithelial hyperplasia, and dense fibrosis. Most described cases have occurred in the major salivary glands, particularly the parotid gland. Although most authorities consider sclerosing polycystic adenosis to be a pseudoneoplastic process, the occurrence of dysplasia and carcinoma in situ of ductal epithelium reported recurrence rates of up to 30%, and recent evidence of clonality suggests a possible neoplastic etiology. However, there have been no cases of metastasis. Herein, we report the first case of sclerosing polycystic adenosis of the sinonasal tract in a 79-year-old woman presenting with a sinonasal mass.

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.