[Sclerosing polycystic adenosis of the submandibular gland]

A Case of Sclerosing Polycystic Adenoma of the Parotid Gland

Sclerosing polycystic adenoma (SPA) is a rare salivary gland tumor with about 100 cases reported in the literature. We describe a case of SPA in the parotid gland and review the diagnostic tools used for identifying SPA. A 24-year-old male with a two-year history of right-sided face mass, initially thought to be pleomorphic adenoma of the parotid gland after fine needle aspiration (FNA). Following superficial parotidectomy, histologic features were consistent with SPA. This case illustrates the challenge of pre-operative assessment for SPA. Recent study has suggested SPA is a neoplasm and definitive treatment is surgical excision.

Clinicopathological profile of sclerosing polycystic adenoma/adenosis: A systematic review

In this systematic review, we aimed to evaluate the clinicopathological profile of sclerosing polycystic adenoma (SPA). PubMed, Scopus, EMBASE, Lilacs, Web of Science, and gray literature were searched to access cases of SPA in salivary glands. One hundred and thirty cases of SPA were found across 61 selected articles. SPA affected mainly the parotid gland of adults with a mean age of 44.6 years old, with a slight preference for females. The lesion was usually presented as a painless firm mass with a long period of evolution. Histologically, they are well-delimitated lesions composed of acinar and ductal elements with a variety of cytomorphologic features surrounded by a densely collagenized stroma. PI3K was the most common gene mutation related to SPA. SPA is a benign condition that mainly affects the parotid gland of female patients and it is usually treated by surgical resection with a good prognosis.

Sclerosing polycystic adenosis of the submandibular gland: Two case reports

BACKGROUND

Sclerosing polycystic adenosis (SPA) is a rare disease of salivary glands, similar to fibrocystic disease of the breast. It occurs over a wide age range and exhibits a slight female preference. Most SPA cases have occurred in the parotid gland. The exact nature of SPA is unclear, but its tumor nature has recently been proposed. Although SPA has a good prognosis after adequate surgery, atypical lesions might occur, ranging from mild dysplasia to carcinoma in situ in some cases. To the best of our knowledge, only five cases of SPA in the submandibular gland have been reported to date. Here, we present two new cases of SPA involving the submandibular gland.

CASE SUMMARY

A 50-year-old woman and a 52-year-old woman were referred to Tongji Hospital in Wuhan, China, with complaints of moderate pain, recurrent swelling, and a mass in the submandibular area. After admission, the two cases of the submandibular mass were examined physically. The boundary of the submandibular tumor was clear, and the range of motion was good. After preoperative examinations, surgery was performed on a selective basis. Postoperative histopathological examination revealed a well-defined mass with acinar structures, ducts, or cystic dilated glands of various sizes scattered in a large number of proliferative sclerosing stroma. There were flat and cuboidal cells, and eosinophils in the duct epithelium. There was also a eosinophilic substance in the lumen of dilated cysts. No atypical epithelial hyperplasia, invasive growth, or carcinoma in situ was found. Based on the above findings, the mass was diagnosed as SPA. Both patients have remained asymptomatic and no recurrence or distant metastasis had occurred by the 7-mo and 5-year follow-up, respectively.

CONCLUSION

SPA is a rare disease of the salivary gland. Even though it has a good prognosis after adequate surgery, atypical lesions may occur from mild dysplasia to carcinoma in situ. However, no recurrence, distant metastasis, or mortality has been reported for submandibular gland SPA. Clinicians and pathologists should be familiar with the characteristics of SPA in the submandibular gland to avoid misdiagnosis and overtreatment.

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.

Salivary gland tumor "wishes" to add to the next WHO Tumor Classification: sclerosing polycystic adenosis, mammary analogue secretory carcinoma, cribriform adenocarcinoma of the tongue and other sites, and mucinous variant of myoepithelioma

This review is a continuation of suggested tumor additions to the next WHO Tumor Classification. The author will focus on four salivary gland entities that have recently become accepted in the literature as new neoplastic entities: sclerosing polycystic adenosis, mammary analogue secretory carcinoma, cribriform adenocarcinoma of the tongue and other sites, and mucinous variant of myoepithelioma.