Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Selected Benign Tumors ++ See Table 24-1. ++Table Graphic Jump LocationTable 24-1Tumors of the Temporal BoneView Table||Download (.pdf) Table 24-1 Tumors of the Temporal Bone Benign Malignant EAC Osteoma SCCA Adenoma BCCA Adenocarcinoma (ceruminous) Melanoma Direct extension of tumors from surrounding areas ME/Mastoid Lipoma/choristoma SCCA Glomus tympanicum Adenoid cystic carcinoma Hemangioma Acinic cell carcinoma Endolymphatic sac tumor Rhabdomyosarcoma Adenomatous neuroendocrine Petrous Apex Schwannoma (facial/vestibular) SCCA Meningioma Osteosarcoma Hemangioma Chondroma Glomus jugulare Lymphoma Chondrosarcoma Metastatic carcinoma to the temporal bone (TB) Direct extension of tumors of the surrounding area BCCA, basal cell carcinoma; SCCA, squamous cell carcinoma. +++ Glomus Tumor (Paraganglioma) ++ Most common neoplasm of the middle ear and second most common neoplasm of the temporal bone/cerebellopontine angle (CPA) Glomus tympanicum (GT) Glomus jugulare (GJ) Glomus vagale (GV) Caucasians more commonly affected Also known as chemodectoma M:F—1:5 May be multicentric (10%) Majority are sporadic; up to 30% are familial Rarely malignant—(2%-4%) with highest risk in vagal paragangliomas Diagnosis requires metastasis to non-neuroendocrine tissue Most common sites are nodal, bone, lung, liver, and spleen Rarely functional—5% or less secrete neuroactive peptides (palpitations, sweating, flushing, syncope, hypertension, headaches) May result in catastrophic hypertension upon induction of anesthesia if not identified and treated preoperatively. If secretory treat with phentolamine (nonselective reversible alpha-adrenergic agent). Functional tumors are rare in extra-adrenal locations. Biology Arise from chemoreceptor cells of the neuroendocrine system Derived from parasympathetic paraganglia in the head and neck Found in the jugular dome, tympanic promontory, along Jacobson and Arnold nerves Type I chief cells, and type II sustentacular cells Genetics Familial tumors are caused by genetic defect in mitochondrial DNA encoding for succinyl dehydrogenase subunits B, C, or D (SDHB, SDHC, SDHD) of mitochondrial complex II; involved in mitochondrial electron transport chain (Table 24-2). Thought to be the mutation in sporadic tumors as well SDH mutations result in pseudohypoxia and upregulation of hypoxia inducing factor 1-alpha. SDHD and SDHC have the highest risk of developing head and neck paragangliomas. Phenotype is maternally imprinted (ie, passed on via male carrier). Explains why phenotype can skip a generation Autosomal dominant Classification schemes (Table 24-3) Fisch Glasscock-Jackson Glomus tympanicum Glomus jugulare Diagnosis Symptoms Pulsatile tinnitus (80%) (GT and GJ) Hearing loss, conductive or mixed (60%) (GT and GJ) Otalgia (13%) (GT and GJ) Aural fullness (32%) (GT and GJ) Hoarseness/dysphagia (15%) (GJ) Facial weakness (15%) (GT and GJ) Functional tumors will present with palpitations, unexplained weight loss, poorly controlled hypertension Physical examination Middle ear mass For diagnosis GT must be able to see 360 degrees around mass, otherwise adjunctive imaging required for diagnosis Brown sign—blanching of middle ear mass with pneumatic otoscopy External auditory canal (EAC) mass Neck mass or pharyngeal fullness Cranial nerve deficits including lower cranial nerve examination Audiogram (GT and GJ) Laryngoscopy (GJ) Diagnostic workup Urine for vanillylmandelic acid (VMA), metanephrines Must be five times higher ... Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth