Dr Kobayashi is a pediatric resident, Children’s Hospital Los Angeles, California.

Ryan Kobayashi, MD

	A 13-year-old boy with poorly controlled type 1 diabetes (T1D) presents to the emergency department (ED) for evaluation of left ear pain and left facial weakness.

	Over the preceding 2 months, he had been evaluated and treated twice at an outside hospital for otitis externa, including a 5-day hospitalization with intravenous (IV) piperacillintazobactam given concern for malignant otitis externa, a rare diagnosis in children, and subsequently completed a course of oral ciprofloxacin and otic corticospinal. He had transient resolution of his symptoms, but for the last 5 days his left ear pain has worsened, and for the last 2 days he has noticed left upper and lower facial weakness. The patient also reports diminished hearing in his left ear and the sensation of left aural fullness.

	The boy has not had any recent fevers or chills at home, denies any other regions of weakness, and has not experienced any dizziness or vertigo. There is no recent travel history, but he had been swimming twice in salt water in the summer prior to the onset of his initial symptoms. His most recent hemoglobin A

 was 10.6%, measured 7 months prior to presentation. He has no previous history of otitis media/externa.

	On presentation to the ED, the patient has a temperature of 99.5°F; heart rate of 76 beats per minute; respiratory rate of 20 breaths per minute; blood pressure of 133/77 mmHg; and oxygen saturation of 99% on room air. Blood pressure normalized on repeat measurement. The patient is comfortable and not ill appearing. Left full-facial droop with loss of the ipsilateral nasolabial fold is noted but neurologic exam is otherwise unremarkable.

	On examination of the left ear, there is mild anterior displacement of the pinna but no overt skin changes at the mastoid or external ear. There is significant pain with manipulation of the pinna and palpation of the mastoid. The external auditory canal is swollen and occluded with granulation tissue, obscuring the tympanic membrane. Heart, lung, abdominal, and skin exams are unremarkable.

	The patient’s white blood cell count is 3860 cells/μL, with 36% neutrophils, 41% lymphocytes, 10% monocytes, and 8% eosinophils. His hemoglobin is 12.4 g/dL and platelets are 425,000/μL. Erythrocyte sedimentation rate is 12 mm/hr. His C-reactive protein is 1.3 mg/dL. Chemistry panel is normal. Urine analysis is normal with no ketonuria or glucosuria.

	Computed tomography (CT) scan of the temporal bone with intravenous (IV) contrast is performed that shows findings consistent with acute otomastoiditis on the left with opacification of the left mastoid air cells and middle ear cavity (Figure). The otolaryngology service is consulted and recommends broad IV antibiotic coverage with vancomycin and cefepime and IV dexamethasone for control of swelling and inflammation around the facial nerve. The patient is admitted for further workup and management.

	Differential diagnosis of facial nerve palsy

	The differential diagnosis for facial nerve palsy in a pediatric patient is quite broad (Table

) and can be categorized into genetic, compressive, traumatic, and infectious/inflammatory etiologies. Notably, the facial nerve takes the longest intraosseous course of any cranial nerve and is therefore at increased risk for injury.

 At certain points in its course, the facial nerve occupies up to 25% to 50% of the area of the bony canal; therefore, in the event of swelling and inflammation, the lack of space for expansion in the canal can impede blood flow and further exacerbate nerve damage.

	(a) Idiopathic facial nerve palsy, more commonly known as Bell's palsy, is the most common etiology in adults; however, secondary causes are more common in the pediatric population (an estimated 70% of cases have an identifiable cause).

	From: Shargorodosky J, et al (1); Lorch M, et al (2); Roob G, et al (3)

	In this case, given the preceding ipsilateral chronic recalcitrant otitis externa in the context of poorly controlled T1DM, the team considers progression to an otitis media with subsequent inflammation of the traversing facial nerve to be the most likely etiology of the deficit. This is further supported by the CT findings that are consistent with the diagnosis of acute otomastoiditis. Of note, otitis media is the most common cause of facial nerve palsy in children, except in areas where Lyme disease is endemic.

	Given this patient’s presentation, a concurrent compressive etiology such as tumor could not be excluded as a cause of obstruction contributing to the chronic external ear infection. The patient’s age of presentation makes a genetic cause unlikely, and the lack of preceding trauma or instrumentation make a traumatic cause unlikely as well. There is no evidence to support an alternate infectious etiology. 

	Following admission, the patient was continued on IV vancomycin and cefepime as well as IV dexamethasone. Magnetic resonance imaging (MRI) of the brain with contrast was performed and no evidence for intracranial extension of the infection was noted. He was subsequently taken to the operating room by the otolaryngology service for left ear examination, left mastoidectomy, and debridement of granulation tissue with otowick placement. Tissue was sent for gram stain, culture, and pathology, and a course of ciprofloxacindexamethasone otic drops was initiated.

	The patient tolerated the procedure well with stable facial weakness and improving pain. Aerobic, anaerobic, and acid-fast bacilli cultures were negative; however, fungal culture grew 

. The patient was started on fluconazole. On postoperative day 2, the team was contacted by the pathology department and informed that initial results from the operating room specimen were consistent with rhabdomyosarcoma, embryonal subtype. In consultation with the otolaryngology and oncology services, the diagnosis was discussed with the patient’s parents and the patient, and he was transferred to the oncology service for further workup and management as well as continued treatment of his otomastoiditis.

	Rhabdomyosarcoma is a mesenchymal tumor derived from the mesodermal germ layer.

 Following neuroblastoma and Wilms tumor, rhabdomyosarcoma represents the third-most common extracranial solid tumor in the pediatric population.

Rhabdomyosarcomas are predominantly seen in children.

 In pediatric patients, 65% are diagnosed in those aged younger than 6 years and the average age of diagnosis is 4 years.

 Incidence is estimated at around 350 new cases in children per year in the United States.

 There is a slight male predominance. Most cases are sporadic but occasionally are associated with familial syndromes such as neurofibromatosis, Li-Fraumeni familial cancer syndrome, Beckwith-Wiedemann syndrome, and Costello syndrome.

	The head and neck region is the most common primary location for this tumor with approximately 40% found in this area.

 The head and neck region can be further subdivided into orbital, parameningeal (ie, middle ear/mastoid, nasopharynx), and superficial (ie, scalp, external ear, buccal, face, neck).

 Middle ear primary tumors are a rare entity, comprising only 3.5% of head and neck rhabdomyosarcoma in a 2010 analysis by Carchi and colleagues.

	Rhabdomyosarcoma can be diagnosed only following a tissue biopsy with careful examination of morphology and immunohistochemistry staining. There are 2 predominant histologic types of rhabdomyosarcoma: embryonal, which appears spindle-like on morphologic exam, and alveolar, which appears as a small, round, blue cell tumor with growth patterns mimicking pulmonary alveoli. Immunohistochemical stains that are diagnostic of rhabdomyosarcoma include myogenic differentiation (MyoD), myogenin (MYOG), desmin, and muscle-specific actin.

	The clinical presentation of rhabdomyosarcoma of the head and neck varies depending on location. Orbital tumors can cause proptosis and ophthalmoplegia. Superficial tumors generally present as painless, enlarging masses. Parameningeal tumors often result in obstructive symptoms with possible superimposed bacterial infection-aural, nasal, or pharyngeal depending on the location.

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	When arising in the middle ear and mastoid, specifically, presentation can be similar to chronic suppurative otitis media with otalgia, purulent and/or blood-tinged ear discharge, possibly resulting in the presence of granulation tissue.

 The neighboring external ear rhabdomyosarcoma, a superficial tumor, often presents as a painless enlarging aural mass that also may obstruct and result in superimposed infection.

	The approach to treatment of rhabdomyosarcoma is multidisciplinary and involves surgery, radiation therapy, and chemotherapy to achieve local/regional disease control and to prevent and/or treat metastasis.

 Complete surgical resection with the least morbidity is the goal. This is usually not possible in patients with parameningeal tumors.

	Radiation therapy is utilized for local disease control and systemic chemotherapy is employed to eradicate primary disease as well as microscopic or gross metastatic disease.

 The gold standard treatment regimen for most stages and prognostic subsets of rhabdomyosarcoma is multiagent therapy with vincristine, dactinomycin, and cyclophosphamide for 45 weeks. Doxorubicin, irinotecan, etoposide, and ifosfamide have been used in the setting of unfavorable, unresponsive, or recurrent tumors.

	Prognostic factors for rhabdomyosarcoma include tumor type; site of primary disease and presence of regional lymph node involvement (stage); extent of resection at diagnosis (group); and the presence of metastatic disease.

 Patients with embryonal histology have a more favorable prognosis than those with alveolar histology. In general, patients with primary tumors in the head and neck region have a better prognosis than those with primaries at other sites, although the parameningeal primary site is considered unfavorable. Distant metastatic disease to the lung, bone, or bone marrow is very unfavorable.

	Following transition of care to the oncology service, the patient had a complete evaluation for metastatic disease, including CT of the head, neck, and chest; nuclear medicine bone scan; bilateral bone marrow biopsies and aspirates; and cerebrospinal fluid examination. None of the tests showed evidence of metastatic disease. The patient had embryonal rhabdomyosarcoma with a parameningeal primary location and no evidence of metastatic disease. This places him in the intermediate risk group as defined by the Children’s Oncology Group with a prognosis of 60% failure-free survival at 5 years.

	The patient began therapy with vincristine, dactinomycin, and cyclophosphamide with radiation therapy for local control. He also completed a prolonged antibiotic course, transitioning to oral augmentin as well as micafungin prior to discharge.

	A complete review of the literature on rhabdomyosarcomas is beyond the scope of this Puzzler. Any child with suspected rhabdomyosarcoma should be referred to a pediatric oncologist.

	1. Shargorodsky J, Lin HW, Gopen Q. Facial nerve palsy in the pediatric population. 

	2. Lorch M, Teach SJ. Facial nerve palsy: etiology and approach to diagnosis and treatment. 

	3. Roob G, Fazekas F, Hartung HP. Peripheral facial palsy: etiology, diagnosis, and treatment. 

	4. Hicks J, Flaitz C. Rhabdomyosarcoma of the head and neck in children. 

	5. Dagher R, Helman L. Rhabdomyosarcoma: an overview. 

	6. Sultan I, Qaddoumi I, Yaser S, Rodriguez-Galindo C, Ferrari A. Comparing adult and pediatric rhabdomyosarcoma in the Surveillance, Epidemiology and End Results Program, 1973 to 2005: an analysis of 2600 patients. 

	7. Abbas A, Awan S. Rhabdomyosarcoma of the middle ear and mastoid: a case report and review of the literature. 

	8. Charchi H, Mansouri N, Harmouch A, et al. Epidemiological, histological and immunohistochemical analysis of head and neck rhabdomyosarcoma in children. 

	9. Eksan M, Noorizan Y, Chew Y, Noorafidah M, Asma A. Rare embryonal rhabdomyosarcoma of external acoustic canal: a case report and literature review. 

	10. Gluth MB. Rhabdomyosarcoma and other pediatric temporal bone malignancies. 

	11. Meza JL, Anderson J, Pappo AS, Meyer WH; Children’s Oncology Group. Analysis of prognostic factors in patients with nonmetastatic rhabdomyosarcoma treated on intergroup rhabdomyosarcoma studies III and IV: Children’s Oncology Group. 

Articles

A 13-year-old boy with poorly controlled type 1 diabetes (T1D) presents to the emergency department (ED) for evaluation of left ear pain and left facial weakness.

Ryan Kobayashi, MD

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Boy with ear pain and facial weakness