1
Introduction
Myospherulosis is a foreign-body reaction to petroleum-based ointments that occurs after surgery or trauma first described in the musculature of 7 patients in 1969 . Since then, there have been numerous reports and scientific studies on this unusual condition, with a preponderance of cases found in the head and neck and, more specifically, in the nose and paranasal sinuses. Here we describe a case and pathology of myospherulosis in the postoperative mastoid space, which has been scarcely reported . Moreover, we provide for the first time modern radiological imaging and surgical views of this unique entity. This case illustrates the importance of including myospherulosis in the differential diagnosis of unresolving postoperative otologic symptoms and serves as a reminder of the potential consequences of placing petroleum-based ointment in the mastoid space.
2
Case report
A 46-year–old man with a history of chronic otitis media with cholesteatoma of the right ear underwent a canal wall up tympanomastoidectomy 3 years before his presentation. His symptoms included hearing loss, chronic otalgia, intermittent tinnitus, and dysequilibrium with vertiginous spells. An audiogram demonstrated a moderate, mixed sloping high-frequency hearing loss with an air-bone gap of 35 to 40 dB in the low frequencies and a 28% word recognition score. A computed tomographic (CT) scan of the temporal bones revealed a right canal wall up mastoidectomy cavity filled with homogenous substance consistent with fat ( Fig. 1 ). Subsequent magnetic resonance imaging (MRI) demonstrated a 23-mm, high-T1, low-T2 signal lesion in the right mastoid bone compatible with a nonenhancing collection ( Fig. 2 ). The operative report from the previous surgery revealed that the surgeon had placed bacitracin ointment into the mastoid space near the conclusion of the case.
To further investigate the contents of the mastoid space and etiologies of the described symptoms, the patient was taken to the operating room for revision surgery. Upon elevation of the periosteal flaps and entrance into the mastoid, it was apparent that the bacitracin from the previous surgery had remained in the cavity and been protected from local clearance mechanisms. The yellow, glue-like substance had consolidated into a spherical shape and was surrounded by edematous inflammatory tissue ( Fig. 3 ). The contents of the mastoid space were removed and sent for pathology. Middle ear exploration revealed no lesions, an intact tympanic membrane, and an ossicular chain in functioning continuity. Iatrogenic defects found in the bony external auditory canal and in bone overlying the posterior semicircular canal were noted and repaired. No other notable abnormalities were found.
Histologic evaluation of the pathologic specimens revealed dense, chronically inflamed fibrous tissue with focal calcification and a scant low cuboidal benign epithelial lining. Moreover, within the subepithelial tissue, there was a prominent lipogranulomatous inflammation consisting of many variably sized cystic spaces lined by multinucleated giant cells and histiocytes imparting a “Swiss cheese” appearance to the tissue fragment ( Fig. 4 A , B). Occasional cystic spaces contained aggregates of degenerated spherical structures representing remnants of red blood cells ( Fig. 4 C). No adipose tissue was found. These characteristic findings were diagnostic of myospherulosis.
Postoperatively, the patient reported a complete resolution of his otalgia and a significant improvement in auditory and vestibular function. An audiogram done 3 months after the procedure revealed a reduction of the air-bone gap (20–25 dB) in the low frequencies and an improvement in word recognition score (72%).
2
Case report
A 46-year–old man with a history of chronic otitis media with cholesteatoma of the right ear underwent a canal wall up tympanomastoidectomy 3 years before his presentation. His symptoms included hearing loss, chronic otalgia, intermittent tinnitus, and dysequilibrium with vertiginous spells. An audiogram demonstrated a moderate, mixed sloping high-frequency hearing loss with an air-bone gap of 35 to 40 dB in the low frequencies and a 28% word recognition score. A computed tomographic (CT) scan of the temporal bones revealed a right canal wall up mastoidectomy cavity filled with homogenous substance consistent with fat ( Fig. 1 ). Subsequent magnetic resonance imaging (MRI) demonstrated a 23-mm, high-T1, low-T2 signal lesion in the right mastoid bone compatible with a nonenhancing collection ( Fig. 2 ). The operative report from the previous surgery revealed that the surgeon had placed bacitracin ointment into the mastoid space near the conclusion of the case.
