Journal of Otology & RhinologyISSN: 2324-8785

All submissions of the EM system will be redirected to Online Manuscript Submission System. Authors are requested to submit articles directly to Online Manuscript Submission System of respective journal.
bahis siteleri bahis siteleri bahis siteleri casino siteleri

Case Report, J Otol Rhinol Vol: 4 Issue: 5

Idiopathic Mastoid Osteoma

David J Mener and C Matthew Stewart*
Department of Otolaryngology-Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, USA
Corresponding author : Dr. C. Matthew Stewart, MD, PhD, FACS,
Department of Otolaryngology-Head & Neck Surgery, Johns Hopkins University, 601 N. Caroline Street, 6th Floor, Baltimore, MD 21287, USA
E-mail: [email protected]
Received: September 26, 2015 Accepted: October 12, 2015 Published: October 17, 2015
Citation: Mener DJ, Stewart CM (2015) Idiopathic Mastoid Osteoma. J Otol Rhinol 4:5. doi:10.4172/2324-8785.1000253

Abstract

In this case report, we describe the rare case of an idiopathic mastoid osteoma. A 40 year old woman complained of tenderness over her right mastoid during exercise and changes in head position. Medical treatment was initially offered with topical corticosteroids, capsaicin, and conservative cervical physical therapy. When her symptoms did not ameliorate, surgical management was then offered. Appropriate surgical planning included computed tomography with threedimensional reconstructions. A mastoidectomy through a postauricular incision for resection was then performed. The osteoma was then removed en bloc with final pathology consistent with a benign compact osteoma of the right mastoid.

Keywords: Mastoid Osteoma; Computed Tomography reconstruction; Facial nerve preservation

Keywords

Mastoid Osteoma; Computed Tomography reconstruction; Facial nerve preservation

Introduction

Osteomas are benign slow growing mesenchymal osteoblastic neoplasms with normal osseous architecture. When these neoplasms occur in the head and neck, they usually occur in the frontoethmoid region or the external auditory canal, with temporal bone osteomas occurring rarely [1]. Temporal bone osteomas may be concerning for patients due to unsightly cosmetic changes or discomfort.
Challenges for the clinician when considering removal include preservation of the facial nerve and ruling out more serious pathology such as osteosarcoma, eosinophilic granuloma, giant cell tumor, Paget’s disease, or osteoblastic metastasis from another anatomic site. In this case report, we discuss in detail the utility of imaging studies including three-dimensional temporal bone reconstruction and clinical factors that ultimately impacted our surgical management.

Case Report

A 40 year old woman of Belgium descent with an unremarkable medical history was referred to neuro-otology for a suspected right mastoid osteoma that had been slowly growing in size for the past several years. She complained of tenderness over her right mastoid, more noticeable with exercise and changes in head position. She denied hearing loss, vertigo, tinnitus, or otorrhea and offered no additional complaints. Physical examination revealed clear external auditory canals, normal pneumatic otoscopy examination, and House-Brackmann score of I/VI. Evaluation of her right mastoid revealed a superficial smooth contiguous firm bony growth on her mastoid tip extending down into her posterior neck. Audiometry revealed normal pure tone testing and word discrimination. Temporal bone computed tomography (CT) Scan without intravenous contrast revealed a 2.1 cm × 1.9 cm × 2.4 cm (anterior-posterior, transverse, cranio-caudal) mass on her right mastoid consistent with a benign osteoma (Figure 1A and B). Medical treatment was initially offered to ameliorate her pain possibly secondary to inflammation or impingement of the sternocleidomastoid muscle with topical corticosteroids and capsaicin applied to the dermis overlying her right mastoid with conservative cervical physical therapy. When her symptoms did not ameliorate after 2 months of treatment, surgical management was then offered. Repeat CT scan with three-dimensional reconstructions was then obtained for surgical planning, which showed slight interval increase in size of the right mastoid osteoma (Figure 2A and 2B). The three-dimensional reconstructions helped illustrate that the facial nerve would be at minimal risk for injury with complete resection.
Figure 1: (A) Axial CT temporal bone without IV contrast showing a 2.1×1.9×2.4 cm pedunculated osteoma on the right temporal bone; (B) Coronal CT temporal bone without IV contrast showing inferior extent of osteoma.
Figure 2: (A) CT temporal bone without IV contrast with three-dimensional reconstruction showing right temporal bone osteoma (posterior/inferior perspective); (B) CT temporal bone without IV contrast with threedimensional reconstruction showing right temporal bone osteoma (right, lateral perspective). Note that osteoma is posterior to styloid process.
A right transmastoid approach through a post-auricular incision for resection of the temporal bone mass was then performed. General anesthesia without paralytic agents in addition to a regional auricular block with 1% lidocaine with epinephrine was used as anesthetic agents. Facial nerve monitoring was utilized throughout the entire surgical case. Noteworthy steps during the operation were elevating the periosteum carefully overlaying the mastoid with extension to the temporal bone mass. Attachments of the sternocleidomastoid muscle to the mass were carefully dissected laterally and inferiorly, freeing the capsule of the temporal bone mass. A right mastoidectomy was then performed with careful identification of the tegmen, sigmoid sinus, and anterior canal wall. This allowed for the temporal bone tumor to be freed superiorly and medially, identifying the appropriate anatomy in order to prevent injury to the facial nerve. The temporal bone mass was then able to be removed en bloc (Figure 3A and 3B). Final pathology was consistent with a benign compact osteoma of the right mastoid (Figure 4). Her symptoms of pain and discomfort at the site of her prior mastoid osteoma abated after resection following her recovery.
Figure 3: (A) Intraoperative photograph of right transmastoid approach for resection. The osteoma was quickly encountered after periosteal elevation. (B) En-bloc resection right temporal bone tumor, consistent with a right compact osteoma on final pathology. Right, Anterior; left, posterior; bottom, lateral.
Figure 4: Representative histopathology slide of specimen consistent with a benign compact osteoma.

Discussion

Mastoid Osteomas are rare benign slow growing osteoblastic neoplasms with an unknown etiology. Temporal bone osteomas have been observed to occur twice as often in women, which is in contrast to external auditory canal osteomas that occur twice as often in men [2]. Approximately one hundred cases have been reported in the world literature [3]. Mastoid osteomas have anecdotally been postulated in some cases to be secondary to trauma, prior surgery, irradiation, chronic mastoiditis, or congenital cholesteatoma [4] although the cause usually remains unknown [5]. Our patient may be best described as having a large pedunculated right mastoid osteoma with compact histological features. Histologically, osteomas are most often described as compact, which comprises dense, compact, and lamellar bone with few vessels and haversian canals. Other histologic types include cartilaginous, spongy, and mixed [6].
CT without intravenous contrast of the temporal bone is the imaging modality of choice in order to ensure there is no intrapetrosal extension. Imaging characteristics classic for mastoid osteomas include a smooth round lesion of the outer cortex with regular margins that is described as pedunculated or sessile. Mastoid osteomas, especially those with petrosal extension, require careful surgical planning in order to avoid injuring critical nearby structures including the facial nerve, lateral semicircular canal, or the ossicular chain. Three-dimensional CT reconstructions are an especially useful adjunct in surgical planning in order to fully appreciate the complete extension of the tumor and to differentiate from normal mastoid cortex.
Differential diagnosis includes osteosarcoma, eosinophilic granuloma, giant cell tumor, Paget’s diseases, fibrous dysplasia, and osteoblastic metastasis, calcified meningioma, osteoid osteoma, hemangioma [1,7-9]. Findings consistent with multiple osteomas should raise the clinical possibility of Gardner’s syndrome, which is associated with colorectal polyposis with malignant degeneration, and require a more in-depth skeletal survey as well as colonoscopy.
Mastoid osteomas may never result in symptoms, or alternatively, may cause local tenderness, inflammation, result in unsightly cosmetic changes with protrusion of the pinnae, interfere with ability to do daily activities with referred pain to the neck, pinnae, or middle ear, or create difficulty in wearing corrective lenses [10]. Initial conservative medical management with observation is appropriate in most cases. Surgery should be reserved for patients where osteomas have resulted in symptoms consistent with pain, tenderness or discomfort, cause cosmetic deformity, or when tissue diagnosis is necessary to rule out malignancy. The osteoma should be excised completely, with the safest approach consistsof performing a mastoidectomy until normal air cells are exposed, identifying critical structures such as the tegmen, sigmoid sinus, and ossicular chain, prior to en-bloc resection. Complications of surgery including facial nerve injury and postoperative otorrhea have been reported [11]. If concerns arise that the osteoma may be in close proximity to the facial nerve exit from the stylomastoidforamen, a facial recess approach may be warranted. Recurrence with complete resection is rare, 11though two cases have been reported [12].

Conclusion

We present a unique case of an idiopathic mastoid osteoma discussing the utilization of modern imaging modalities and considerations for surgical planning. Given that our patient had symptoms interfering with her quality of life, surgical resection was warranted. Imaging revealed that the facial nerve was at minimal risk with en-bloc resection after an appropriate mastoidectomy and dissection. Risks and benefits of surgery need to be discussed in depth with patients, especially with a strong suspicion of benign disease.

Acknowledgment

All authors contributed to the study concept and design, analysis and interpretation of data, and preparation of the final manuscript.

References













Track Your Manuscript

Media Partners

Associations