Metastatic Cutaneous Adnexal Carcinoma of the Head and Neck With Durable Response to an Aromatase Inhibitor Combined With a Cyclin-Dependent Kinase 4/6 Inhibitor.

Abstract

Cutaneous adnexal carcinomas are a very rare group of cancers arising from appendageal structures of the skin. More than half occur in the head and neck region. No standard treatments exist for metastatic disease. A 48-year-old postmenopausal female presented with an enlarging scalp lesion. Biopsy showed adenocarcinoma that was positive for estrogen and progesterone receptors. She underwent wide local excision with adjuvant radiation. Unfortunately, she presented with metastatic disease 1.5 years later. Given the tumor's hormone receptor profile, she was started on an aromatase inhibitor (AI) and a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor with a durable partial response for 2.5 years at the time of this report. She continues to work full-time. This is the first case study describing the success of hormonal therapy combined with a CDK4/6 inhibitor for a rare head and neck cancer. Cutaneous adenocarcinomas in the head and neck region should have routine immunohistochemical assessment of hormone receptors.