The Laryngoscope Lippincott Williams & Wilkins © 2007 The American Laryngological, Rhinological and Otological Society, Inc. Actinomycosis of the Temporal Bone With Labyrinthine and Facial Nerve Involvement Deepak Mehta, FRCS(ORL); Melissa Statham, MD; Daniel Choo, MD, PhD Objectives: To demonstrate the clinical, radio- logic, and pathologic findings of actinomycosis of the temporal bone. Study Design: Case report and literature review. Methods: Analysis of a case through medical records and literature review. Results: Actinomycosis is a rare cause of subacute- chronic suppurative infection of the temporal bone. We present an 11-year-old male with a history of ciliary dys- kinesia presenting with a 6-week history of right-sided otorrhea, otalgia, and a 1-week history of progressive facial weakness. Final histopathology revealed a diagno- sis of actinomycosis. A review of the literature showed 25 cases of temporal bone actinomycosis. This is the first reported case of actinomycosis causing facial nerve palsy and labyrinthine invasion. Effective treatment includes aggressive surgical debridement followed by long-term administration of appropriate antibiotic. Conclusions: Actinomycosis can be a cause for bone erosive lesions of the temporal bone and can result in significant morbidities. Prompt tissue diagnosis with sus- picion for nonmalignant causes of bone erosive disease can help in implementing appropriate treatment. Key Words: Actinomycosis, temporal bone, facial nerve paresis. Laryngoscope, 117:1999 –2001, 2007 INTRODUCTION Actinomycosis is a Gram-positive, anaerobic, nonacid- fast, filamentous bacterium. Actinomycosis israeli is the most common pathogenic species of this bacteria found in humans. Actinomycosis infection is most commonly seen after minor trauma in the cervicofacial region (approxi- mately 55% of cases) as well as the abdomen and the thorax. Involvement of the temporal bone by actinomyco- sis is rarer and has been presumed to be to be caused by direct spread via the eustachian tube from the nasophar- ynx, where actinomycetes can be a commensal organism. 1 CASE REPORT An 11-year-old male with a prior history of primary ciliary dyskinesia (PCD) with bronchiectasis presented with a 6-week history of right-sided otorrhea, otalgia, and 1 week of progressive facial nerve paresis. On examina- tion, the left ear was normal, whereas the right ear canal showed a pale polypoid mass completely occluding the external auditory canal. A grade V House-Brackman fa- cial paresis was noted on the right side. 2 There was no history of tinnitus or vertigo. The patient had recently undergone ventilation tube insertion for chronic otitis me- dia with effusion 4 months prior to this presentation. Pure tone audiometry demonstrated a profound sensorineural hearing loss on the right side and a normal-hearing left ear. A high-resolution computed tomography scan of the temporal bone (Fig. 1) revealed complete opacification of the mastoid air cells, middle ear, and bony external audi- tory canal. The ossicular chain was eroded, and a large, bony defect of the lateral semicircular canal was also noted. The lateral wall of the epitympanum and scutum were eroded as well. The tympanic portion of the facial nerve was poorly visualized because of the soft tissue attenuation, but the remaining portions of the fallopian canal otherwise appeared normal. Gadolinium-enhanced magnetic resonance imaging (MRI) provided enhance- ment of the middle ear, mastoid, labyrinth, cochlea, and internal auditory canal. MRI did not demonstrate evi- dence of intracranial involvement (Fig. 2). Initially, the patient was taken to the operating room for a biopsy to evaluate suspected malignancy. Histologic examination found a specimen to contain inflammatory cells with no evidence of malignancy. One week later, mastoid exploration was performed. Pale granulation tis- sue filled the mastoid and was sent for frozen section. After confirming that there was no evidence of malig- nancy, a canal wall down mastoidectomy with partial lab- yrinthectomy was performed. The tissue was sent for rou- tine histopathology and comprehensive microbiology (aerobic, anaerobic, fungal, and acid fast Bacillus cul- tures). Intraoperatively, the gritty granulation tissue was tracked into the lumen of the lateral semicircular canal and vestibule. Aggressive debridement (including exenter- ation of the lateral canal and utricle) was performed until normal, healthy bone was evident. The facial nerve was found to be dehiscent at the second genu. Ossicular erosion From the Department of Pediatric Otolaryngology, Cincinnati Chil- dren’s Hospital and Medical Center, Cincinnati, Ohio, U.S.A. Editor’s Note: This Manuscript was accepted for publication June 4, 2007. Send correspondence to Dr. Deepak Mehta, Department of Pediatric Otolaryngology, Cincinnati Children’s Hospital and Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229. E-mail: deepakmehta71@yahoo.com DOI: 10.1097/MLG.0b013e318133a127 Laryngoscope 117: November 2007 Mehta et al.: Actinomycosis of Temporal Bone 1999