Journal
AMERICAN JOURNAL OF SURGICAL PATHOLOGY
Volume 45, Issue 10, Pages 1337-1347Publisher
LIPPINCOTT WILLIAMS & WILKINS
DOI: 10.1097/PAS.0000000000001688
Keywords
salivary gland neoplasms; adenocarcinoma not otherwise specified; mucinous adenocarcinoma; papillary cystadenocarcinoma; signet ring carcinoma; AKT1; salivary intraductal papillary mucinous neoplasm
Funding
- Jane B. and Edwin P. Jenevein, MD Endowment for Pathology at UT Southwestern Medical Center
Ask authors/readers for more resources
The clinicopathologic and molecular features of salivary mucinous adenocarcinomas were evaluated for classification clarification, revealing a histologically diverse single entity closely related to salivary intraductal papillary mucinous neoplasm. A unified mucinous adenocarcinoma category subdivided into papillary, colloid, signet ring, and mixed subtypes is proposed for better recognition and classification of these tumors, with recurrent AKT1 E17K mutations across patterns suggesting their close relationship.
Mucin-producing salivary adenocarcinomas were historically divided into separate colloid carcinoma, papillary cystadenocarcinoma, and signet ring cell carcinoma diagnoses based on histologic pattern, but have recently been grouped together in the adenocarcinoma not otherwise specified category. It is currently unclear if these tumors represent 1 or more distinct entities and how they are related to well-circumscribed papillary mucinous lesions with recurrent AKT1 E17K mutations that were recently described as salivary intraductal papillary mucinous neoplasm. Here, we sought to evaluate the clinicopathologic and molecular features of salivary mucinous adenocarcinomas to clarify their classification. We identified 17 invasive mucin-producing salivary adenocarcinomas, 10 with a single histologic pattern, and 7 with mixed patterns. While most tumors demonstrated papillary growth (n=15), it was frequently intermixed with colloid (n=6) and signet ring (n=3) architecture with obvious transitions between patterns. All were cytokeratin 7 positive (100%) and cytokeratin 20 negative (0%). Next-generation sequencing performed on a subset demonstrated recurrent AKT1 E17K mutations in 8 cases (100%) and TP53 alterations in 7 cases (88%). Of 12 cases with clinical follow-up (median: 17 mo), 4 developed cervical lymph node metastases, all of which had colloid or signet ring components. Overall, overlapping histologic and immunohistochemical features coupled with recurrent AKT1 E17K mutations across patterns suggests that mucin-producing salivary adenocarcinomas represent a histologically diverse single entity that is closely related to tumors described as salivary intraductal papillary mucinous neoplasm. We propose a unified mucinous adenocarcinoma category subdivided into papillary, colloid, signet ring, and mixed subtypes to facilitate better recognition and classification of these tumors.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available