Abstract
Purpose
Polyarteritis nodosa is one of the common forms of vasculitis with multiorgan involvement. Hearing loss may be the presenting symptom of this disease. The aim of this histopathologic study was to evaluate temporal bone changes in polyarteritis nodosa and assess the correlation between otologic manifestations and histopathologic findings.
Materials and methods
A retrospective human temporal bone analysis was performed at an otopathology laboratory in a tertiary academic medical center. Three cases (5 temporal bones) with pathologically confirmed diagnosis of polyarteritis nodosa were selected for study. The processed temporal bone sections were studied under light microscopy.
Results
Two of the 3 cases presented with hearing loss, and one of them had facial palsy. Audiometric data available for one patient demonstrated a bilateral, rapidly progressive, mixed hearing loss. Histopathologically, we found generalized vasculitis involving small- and medium-sized arteries in all cases. Of the 5 temporal bones available for study, 3 had chronic otitis media and 2 had serous otitis media. Arteritis was seen in all middle ears. There was disruption of the organ of Corti and spiral ganglion cells in 4 temporal bones. One temporal bone showed fibrosis and osteogenesis in the scala tympani of the basal turn. Vasculitis of stylomastoid and branches of labyrinthine artery were also found in temporal bones.
Conclusions
Significant temporal bone findings were seen in patients with polyarteritis nodosa, including otitis media, cochlear damage, neo-osteogenesis, and middle and inner ear vasculitis. This temporal bone series also suggests an interesting relationship between sensorineural hearing loss and labyrinthine vasculitis.
1
Introduction
Polyarteritis nodosa is a type of systemic vasculitis causing segmental necrosis and inflammation in the walls of medium-sized arteries. The disease is multisystemic and involvement of organs is diffuse, although some systems are affected more often than others. It commonly involves the kidneys (70%), skeletal muscle (60%), skin (40%), heart (35%), and central nervous system (25%) .
Thus, depending on the organ system involved, the presenting symptom may vary from patient to patient. It is important for the clinician to recognize these symptoms and initiate appropriate investigation and treatment to prevent further progression of the disease. The importance of polyarteritis nodosa in otology is because hearing loss (conductive, sensorineural, or mixed) may be its presenting symptom . Polyarteritis nodosa may be the secondary cause of what is popularly referred to as autoimmune inner ear disease . The facial nerve is the most common cranial nerve affected, and these patients may present with a facial palsy. Sudden onset of sensorineural hearing loss is an otologic emergency, and in these patients, it is important to evaluate systemic causes of otologic disease. This may enhance the response to systemic treatment and also help in preventing devastating sequelae.
In this article, we present 3 cases of polyarteritis nodosa, with temporal bone pathology, and also review the literature of its effects on the temporal bone and subsequent histopathologic and clinical manifestations.
2
Materials and methods
All the temporal bones used in this study had been previously obtained at autopsy. They were fixed in formalin solution, decalcified, and embedded in celloidin. Temporal bones were serially sectioned in the horizontal plane at a thickness of 20 μ m. Every tenth section was stained with hematoxylin and eosin and mounted on glass slides for light microscopic study.
2.1
Case 1
A 53-year-old man presented to the neurology clinic with right-sided facial weakness of 1 week duration. He had a history of sudden-onset, nonprogressive hearing loss in his right ear for 4 months and tinnitus in his right ear for 3 weeks before his hospital visit. He had frequent episodes of “head colds,” occipital headaches, and occasional dizzy spells. Evaluation for acoustic neuroma was negative. The patient was diagnosed with diabetes mellitus and hypertension. Audiologic examination revealed a moderate sensorineural hearing loss in the left ear with a small conductive component and some impairment in speech discrimination. The right ear had a severe mixed loss with a 15- to 20-dB air-bone gap in the lower frequencies ( Fig. 1 A ). Short Increment Sensitivity Index scores were positive with a type II Bekesy recording bilaterally. At follow-up, 3 months later, right facial function showed partial improvement. Repeat audiometry showed a severe mixed loss in the left ear with poor discrimination and a 20- to 30-dB air-bone gap in the speech frequencies ( Fig. 1 B). There was total hearing loss in the right ear. The patient was hospitalized 2 months later for severe weight loss, dysphagia, dysarthria, pedal edema, paresthesia, and numbness of limbs. He developed renal failure and was started on systemic steroids and peritoneal dialysis. In spite of aggressive treatment, the patient died of progressive pulmonary congestion and pneumonia. Postmortem examination revealed polyarteritis nodosa involving the kidneys, left adrenal gland, appendix, abdominal aorta, and sciatic nerve.
2.1.1
Left temporal bone
Middle ear mucosa was thickened with chronic inflammatory cell infiltration and granulation tissue. There were numerous cystic spaces filled with seropurulent effusion. Vessel walls in the submucosal space were markedly thickened and inflamed. Arteritis was more obvious in vessels of the fallopian canal accompanying the facial nerve. The perilymphatic space of the cochlea appeared normal. Organs of Corti were reduced to a “mound of cells” throughout all turns. The stria vascularis appeared normal. The spiral ligament showed atrophy, more in the middle and apical turns. The number of spiral ganglion cells was reduced in all turns. Modiolar vessels and branches of the labyrinthine artery at the fundus of the internal auditory canal were inflamed and the vessel lumens reduced in caliber by fibrosis ( Fig. 2 ). Vestibular structures appeared normal.
2.1.2
Right temporal bone
There were chronic inflammatory changes of the middle ear, similar to the left side, including vascular changes in subepithelial vessels. The vessels in the fallopian canal showed evidence of vasculitis and reduced caliber due to fibrosis. Loose areolar-type fibrous tissue and chronic inflammatory cells were seen in the scala tympani in the hook portion of the cochlea. There was granulation tissue in the round window niche that obliterated the round window membrane and extended into an area of osteoneogenesis of the scala tympani of the basal turn ( Fig. 3 ). Organs of Corti were reduced to a “mound of cells” in all turns, and tectorial membranes were collapsed. The stria vascularis appeared normal, but the spiral ligament showed atrophy similar to the left side. The spiral ganglion cell population was decreased, mainly in the area of the basal turn. Vessels in the modiolus and small labyrinthine vessels in the internal auditory canal were thickened. The vestibular structures were normal.
2.2
Case 2
A 69-year-old man was diagnosed by muscle and kidney biopsy to have polyarteritis nodosa and Wegener granulomatosis. His symptoms started with bilateral otalgia and drainage from the right ear. He also complained of decreased hearing in both ears. On his first visit to the otolaryngology clinic, his tympanic membranes were dull, moderately retracted, and moved sluggishly. A diagnosis of bilateral serous otitis media was made, and he eventually received tympanostomy tubes bilaterally. Audiometry reports were not available. Mastoid x-rays revealed bilaterally sclerotic mastoids. During the next 2 years, the patient had several hospital admissions for treatment of serous otitis media, chronic sinusitis, peripheral neuropathy, joint complaints, pulmonary problems, and renal problems characterized by proteinuria, hematuria, and abnormal creatinine clearance.
The patient had his last admission at the age of 71, when he complained of abdominal pain and hematochezia. He was being treated with steroids and died 9 days later. Autopsy confirmed diagnosis of polyarteritis nodosa and Wegener granulomatosis.
2.2.1
Right temporal bone
The tympanic membrane was thickened. There was seropurulent effusion in the middle ear cleft. Vasculitis was observed in the submucosal vessels of the middle ear cavity and those around the facial nerve in the fallopian canal. Arteritis was evident in the stylomastoid artery, which had fibrotic hypertrophy of the vessel wall and narrowing of the lumen. The vestibule appeared normal. Organs of Corti were reduced to a “mound of cells” in all turns, and the tectorial membranes appeared to be collapsed over those cells. The modiolar vessels appeared normal. The stria vascularis showed infiltration with a brown-colored pigment and hyperemic changes. The spiral ganglion cell population was reduced in the middle and basal turns.
2.2.2
Left temporal bone
The pathology of the middle and inner ears was similar to the contralateral ear.
2.3
Case 3
A 69-year-old man was admitted to the hospital with complaints of precordial pain, radiating to his left arm, 3 days before admission. He had a long-standing history of atherosclerotic heart disease and had been treated with nitroglycerin for about 20 years.
He had myocardial infarction at the age of 61. On admission, he was febrile with bloody stools and atrial fibrillation. This cardiac arrhythmia was treated with quinidine, and he gained normal sinus rhythm. His LE clot test was positive (4+). Sputum and urine cultures grew out Pseudomonas , and urine analysis revealed proteinuria and red and white blood cells. The patient developed ventricular tachycardia. He had a blood urea nitrogen of 57 and creatinine of 2.4, and a falling urine output. Eleven days after admission, he died of asystole and renal failure.
Postmortem examination revealed new and old myocardial infarctions secondary to atherosclerotic heart disease. Histologic changes seen in the medium-sized arteries suggested acute and chronic polyarteritis.
2.3.1
Left temporal bone
The tympanic membrane and ossicles appeared normal. The middle ear cavity and mastoid air cells were filled with seropurulent effusion. The mucoperiosteum of mastoid cells was thickened, hyperemic, and sparsely infiltrated with chronic inflammatory cells. There was arteritis of the submucosal vessels in the middle ear cleft and of vessels in the fallopian canal ( Fig. 4 ). Mononuclear cells were predominantly found surrounding medium-sized vessels peripheral to the greater petrosal nerve. The tunica adventitia, media and intima of these arterioles, and the stylomastoid artery were thickened and the lumen caliber reduced. No inflammatory cell infiltration of vessel layers was observed. There were pus and granulation tissue in the round window niche. The inner ear appeared normal.
