Abstract

Introduction: Malignant cutaneous adnexal tumors remain rare entities affecting older adults and individuals with familial tumor syndromes. The vast majority of malignant adnexal tumors discussed herein are differentiated by clinicopathologic features including size, infiltrative growth, pleomorphism, mitosis, and necrosis. Here, we present the clinicopathologic and genomic landscape of 162 malignant adnexal tumors. Methods: Individual tumors were analyzed utilizing comprehensive genomic profiling to identify genomic alterations. Tumors were then filtered by discrete diagnosis to identify and quantify mutations in each subset of adnexal tumor. Results: Clinicopathologic characteristics of included cases consisted of 59% (96/162) males, 41% (66/162) females with age ranging from 26-100 years (mean =68). The total number of molecular alterations identified within this series was 1,413 alterations. After review of the rendered diagnoses, the case series included 53 sebaceous carcinomas, 24 hidradenocarcinomas,18 eccrine carcinomas, 15 porocarcinomas, 13 digital papillary carcinomas, 11 spiradenocarcinomas/cylindrocarcinoma, 8 pilmoatrical carcinomas, 6 microcystic adnexal carcinomas, 5 malignant mixed tumors, 3 trichilemmal carcinomas, 2 invasive Paget’s carcinomas, 2 syringocystadenocarcinomas, and 2 adenoid cystic carcinomas. Overall, the most common mutations identified included TP53, TERT, RB1, PTEN, PIK3CA, and NOTCH1. The number of mutations per case varied from 24 unique alterations in a case of hidradenocarcinoma, to a single mutation in 24 cases (most commonly digital papillary carcinoma). Conclusion: Malignant cutaneous adnexal tumors are diverse clinically, histologically, and molecularly. Identifying the molecular alterations can help further classify these tumors and in certain instances provide actionable alterations to aid in treatment decisions in advanced disease

Financial Disclosure:
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