二次性側頭骨悪性腫瘍による顔面神経麻痺

Abstract

Shun-ichi Imamura, Kaori Hashimoto, Mayumi Imamura, Izuru Nozawa, Ken-ichi Hisamatsu and Yoshihiko Murakami (Yamanashi Medical University)Peripheral facial palsy caused by secondary malignant tumors of the temporal bone from distant or adjacent primary tumors is thought to be rare. We encountered nine patients with facial palsy resulting from secondary neoplastic invasion to the temporal bone from various primary sites (liver, lung, breast, eyelid, hypopharynx, maxillary sinus, renal pelvis, and leukemia) during a period of approximately 10 years (between 1983 and 1992). The incidence of this type of etiology accounted for 5.2% (9/173) of all patients with facial palsy who were treated at our institution during that period.We also performed histopathologic studies of the temporal bones acquired from five patients who had presented facial palsy of varying degrees before death due to secondary malignant tumors and the correlation between their clinical and histological findings was investigated.The results obtained in the present study were summarized as follows:1) The present study and our comprehensive review of the literature indicated that the most common clinical symptom in patients with secondary malignant tumors of the temporal bone was facial palsy, followed by hearing loss, otalgia, etc.2) It also became apparent that there were three basic routes of tumor invasion from primary tumors to the intratemporal portion of the facial nerve: 1. hematogenous dissemination of neoplastic cells to the bone marrow or pneumatized area of the temporal bone destroying the Fallopian canal,2. direct extension of malignant tumors adjacent to the temporal bone involving the Fallopian canal,3. leptomeningeal metastatic carcinomatosis involving the internal auditory meatus and destroying the facial nerve trunk directly. Clinical otologic features including facial palsy tended to differ depending on the extension route of the malignancy to the temporal bone and facial nerve.3) Although metastatic or secondary temporal bone malignancies are rare and the clinical symptoms usually appear late in the course of disease, otologists should be aware of existence of this disease entity, since otologic symptoms such as that for facial palsy or hearing loss may be the only initial sign of tumor in selected patients.