External auditory canal metastasis leading to peripheral facial paralysis as first manifestation of de novo stage IV invasive lobular carcinoma of the breast: a rare case report

Abstract

Facial nerve (FN) palsy, as a solitary symptom resulting from a metastatic tumor, is uncommon, and metastases to the external auditory canal (EAC) are even more infrequent. In this article, we report a unique case of the de novo stage IV invasive lobular breast carcinoma (LBC) presenting as an EAC metastasis and leading to FN palsy as the first symptom, highlighting the importance of considering a broad differential diagnosis.