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CHAPTER 28 Squamous Cell Carcinoma (Middle Ear)
Douglas J. Quint
Epidemiology
Primary middle ear squamous cell carcinoma is a rare neoplasm seen in less than 1 in 10,000 patients presenting with otologic disease. It is less common than primary external auditory canal squamous cell carcinoma.
This rare carcinoma is most often seen in 50- to 60-year-old men. It is associated with chronic otitis media, which is associated with increased cellular metaplasia due to ongoing infl ammation/otorrhea possibly mediated through human papilloma virus (which is present in many of these patients). These carcinomas are also associated with prior radiation therapy.
These patients have a poor prognosis, as most present with advanced disease (e.g., temporal bone or intracranial extension) and it is diffi cult, if not impossible, to achieve complete neoplasm resection because many crucial structures are nearby (brain, skull base internal carotid artery, cavernous sinus, dural venous sinuses, etc.). Five-year survival is less than 50% in patients who are treated with surgery and radiation therapy.
Clinical Features
These patients present with a long history of ear symptoms, namely pain, discharge, bleeding, and re- fractory granulation formation. These patients may also have facial palsy refl ecting involvement of the tympanic portion of cranial nerve VII. Sudden deafness can be seen late in the course of the disease.
The clinical scenario of seventh nerve palsy, deafness, and continuing otorrhea should suggest a middle ear process. The diagnosis is often initially overlooked, as middle ear squamous cell carcinoma is a rare entity and all of the symptoms seen in these patients (except for the facial nerve palsy) are typical of chronic otitis media.
Pathology
Middle ear squamous cell carcinoma probably arises from tympanic mucosa. Temporal bone squamous cell carcinomas are considered stage 1 and 2 when limited to the external auditory canal. By defi nition, they are considered stage 3 when they involve the middle ear (stage 4 lesions involve the temporal bone more extensively). Cases of primary middle ear squamous cell carcinoma are so rare that there are no reliable statistics as to whether these lesions metastasize. As mentioned above, these patients have a poor prognosis primarily due to their overall late presentation.
Treatment
Treatment for middle ear (and all temporal bone) squamous cell carcinomas includes surgery, chemo- therapy, and postsurgical radiation therapy. In cases of extensive disease, palliative radiation therapy only may be performed.
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Imaging Findings
As most of these lesions present at a relatively late stage, frank invasion and destruction of portions of the temporal bone is often already present. The extent of temporal bone (including ossicular) de- struction is best assessed with computed tomography (CT), whereas delineating trapped secretions from invasive tumor and defi ning the extent of extratemporal involvement (intracranial, intravascular, infratemporal, etc.) is best assessed with magnetic resonance imaging (MRI).
Soft tissue masses in the middle ear cleft are usually nonspecifi c in appearance on CT and MRI, con- sistent with both infl ammatory and neoplastic processes.
CT
High-resolution (1–2 mm) noncontrast CT performed in the axial and coronal planes and reconstructed with a “detail” (bone) algorithm best delineates the extent of temporal bone (including ossicular) involvement. Occasionally, sagittal reformatted images may prove valuable. If MRI is not available, intracranial, infratemporal, and vascular involvement can be grossly assessed by contrast-enhanced CT, but usually the extent of disease is best assessed with MRI and no contrast-enhanced CT imaging is necessary ( Fig. 28–1 ). Contrast-enhanced CT can be used to search for associated cervical adenopathy.
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Figure 28–1 A 44-year-old man presents with a 2-year history of right ear itching, with minimal associated pain and drainage. Biopsy revealed squamous cell carcinoma.
Coronal (left) and axial (right) noncontrast computed tom- ography (CT) scans through the right temporal bone dem- onstrate abnormal right external and middle ear region soft tissue ( arrows ) with associated temporal bone and os-
sicular destruction. It is impossible to differentiate trapped secretions from tumor. After failing to tolerate radiation therapy, surgery confi rmed the unresectable nature of the tumor, which involved the entire middle ear including the geniculate, tympanic, and the second genu portions of the seventh nerve and the region of the carotid artery and eus- tachian tube.
28 SQUAMOUS CELL CARCINOMA (MIDDLE EAR) 101
MRI
Thin-section multiplanar pre- and postcontrast T1- and T2-weighted scanning is best for delineating the extent of intrinsic and extrinsic temporal bone carcinoma ( Fig. 28–2 ). The extent of intraosseous, intracranial, vascular, and extracranial (subtemporal, scalp, external ear) spread by neoplasm, and perineural spread by neoplasm is best delineated on multiplanar fat-suppressed T2 and contrast- enhanced T1 MRI. Distinguishing trapped middle ear and mastoid secretions from tumor is also best achieved with MRI. Cervical lymph nodes can also be detected on fat-suppressed contrast-enhanced MRI for staging purposes.
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Figure 28–2 A 56-year-old woman presents with 6 months of right oral “fullness,” several weeks of hemorrhagic ot- orrhea, and 2 days of right-sided facial paresis. Imaging revealed a temporal bone mass that at biopsy proved to be squamous cell carcinoma. Axial (upper left) and coro- nal (lower left) contrast-enhanced T1-weighted and axial T2-weighted (upper and lower right) magnetic resonance imaging (MRI) scans through the right temporal bone re-
gion demonstrates the enhancing right temporal bone carcinoma ( black T ) centered in the external auditory canal region with temporomandibular joint region and middle ear region ( white T ) extension. The T2-weighted MRI scans permit differentiation of tumor (isointense to brain) from mastoid-trapped secretions (m), which is diffi cult on the contrast-enhanced T1-weighted scans and is impossible on CT scans.
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Differential Diagnosis
Imaging fi ndings are nonspecifi c. Other more common middle ear infl ammatory or aggressive neoplas- tic processes should always be considered in these patients.
Symptoms of an aggressive or chronic otitis media can mimic middle ear squamous cell carcinoma and are much more common clinical entities than carcinoma. An aggressive jugulotympanic paragangli- oma can present similar to a temporal bone carcinoma, but is a more common neoplastic process. Other malignancies that are more commonly seen than primary middle ear carcinoma include metastatic disease, malignant adenomatous tumors, sarcomas (particularly in children), and perineural spread by adenoid cystic carcinoma or extratemporal squamous cell carcinoma.
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In the setting of chronic, recurrent infl ammatory disease of the middle ear, new facial paralysis or acute hearing loss should prompt a search for carcinoma with aggressive CT imaging.•
Once a destructive, permeative temporal bone process has been detected with CT scanning, the ex- tent of disease with special attention to intracranial, vascular, and subtemporal involvement is best delineated with MRI.•
Cervical adenopathy can be assessed with either CT or MRI. Detecting extratemporal involvement by this carcinoma affects management.Suggested Readings
Agada FO , Gnananandha C , Wickham M . Squamous cell carcinoma of the middle ear: case report and literature review . Annals of African Medicine 2004 ; 3 : 90 – 92
Suzuki K , Takahashi M , Ito Y , et al . Bilateral middle ear squamous cell carcinoma and clinical review of an additional 5 cases of middle ear carcinomas . Auris Nasus Larynx 1999 ; 26 : 33 – 38
Swartz JD, Harnsberger HR, eds. Imaging of the Temporal Bone, 3rd ed. New York: Thieme, 1998 Takano A , Takasaki K , Kumagami H , Higami Y , Kobayashi T . Clinical records: a case of bilateral middle-
ear squamous cell carcinoma . J Laryngol Otol 2001 ; 115 : 815 – 818
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CHAPTER 29 Adenomatous Lesion
Douglas J. Quint
Epidemiology
The neoplasms discussed in this chapter (middle ear adenomas, carcinoids, adenocarcinoma, and en- dolymphatic sac tumors) are considered different types of adenomatous lesions and are each very rare.
Clinical Features
Middle ear adenomas and carcinoids are nonaggressive neoplasms that can present clinically in a manner similar to other more common benign middle ear masses such as primary or secondary chole- steatoma or paraganglioma. They appear as a retrotympanic mass at otoscopy. Symptoms include a feeling of ear “fullness,” tinnitus, and conductive hearing loss. These lesions usually do not involve the facial nerve and therefore do not present with seventh nerve palsy.
Middle ear endolymphatic sac tumors are more aggressive neoplasms and often present with sev- enth nerve involvement in addition to the above-described symptoms.