Temporal Bone Carcinoma: Results of Surgery for Primary and Secondary Malignancies

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1 ORIGINAL ARTICLE Temporal Bone Carcinoma: Results of Surgery for Primary and Secondary Malignancies Milan Stankovic, M.D. From the Department of Otorhinolaryngology, Medical Faculty Nis, Serbia. Correspondence: Milan Stankovic, M.D. Pustorecka 33, Nis, Serbia Tel: Fax: Submitted: June 13, 2004 Accepted: January 3, 2005 Mediterr J Otol 2005;1: Copyright 2005 The Mediterranean Society of Otology and Audiology OBJECTIVES: The aim of this study was to analyze the clinical characteristics and surgical results of a series of patients who underwent surgery for primary or secondary temporal bone tumors. PATIENTS AND METHODS: Twenty patients underwent surgical treatment for malignant tumors of the external auditory canal and the middle ear. There were 16 males and four females, with a mean age of 66 years (range 37 to 79 years). Eight patients had primary, 12 patients had secondary temporal bone tumors. Primary tumors involved the middle ear or the ear canal, while secondary tumors originated from the auricle, its neighborhood, or the parotid gland. Computed tomography was used to assess the extent of involvement. Tumor staging was made according to the system proposed by Arriaga et al. Partial (n=7) or total (n=2) temporal bone resections, or a subtotal resection (petrosectomy) (n=11) were performed. All the patients received postoperative irradiation at a total dose of 6,000 cgy in 30 fractions for six weeks. Clinical characteristics, types of operations, and survival were analyzed. Statistical analysis was made using the chi-square test. RESULTS: Otalgia, otorrhea or bloody otorrhea were the main complaints. Primary tumors were at an advanced stage in most of the patients, with destruction of the surrounding bone in four, involvement of the endocranium in two, paralysis of the facial nerve in five, and total hearing loss in seven patients. The diagnosis was established before surgery in four patients. Surgery was planned for suspected chronic otitis in four patients. Histopathologic diagnosis of primary tumors was squamous cell carcinoma in all the cases. Significant differences were found between primary and secondary temporal bone tumors with respect to symptoms and the type of operation (p<0.05). The overall five-year survival rates were 37.5% (3/8) and 58.3% (7/12) for primary and secondary temporal bone malignancies, respectively. Patients with free margins had a significantly better survival (9/11, 81.8%) than those with positive margins (1/9, 11.1%) (p<0.05). Patients with lymph node involvement had a very poor survival (19%). Local recurrence was the cause of death in all the cases with a mean of 4.1 months from recurrence to death. The extent of surgery did not have any significant influence on the survival (p>0.05). CONCLUSION: The prognosis of carcinomas involving the temporal bone is directly related to the extent of tumoral propagation. Early diagnosis, appropriate selection of patients and the surgical technique, together with reconstruction, and postoperative radiotherapy may enable an improved survival and quality of life. 01

2 Temporal Bone Carcinoma: Results of Surgery for Primary and Secondary Malignancies Tumors of the temporal bone may be histologically benign (adenoma, inverted papilloma, meningioma) or malignant. Malignant lesions include primary (squamous cell carcinoma, adenocarcinoma), metastatic (from breast, lungs, kidney, stomach, larynx), and secondary (basal-cell carcinoma, squamous cell carcinoma, other carcinomas, and sarcoma) tumors. Tumors involving the temporal bone are not frequently seen; but they have a very aggressive course and poor prognosis. Clinical manifestations are often not specific. Due to a rapid progression, the disease is usually detected at an advanced stage, with limited therapeutic success. There is not a universally accepted classification system, making the selection of therapeutic modalities very problematic. Therefore, assessment of various surgical techniques developed for temporal bone resection is considerably difficult. [1-3] The aim of this study was to analyze the clinical characteristics and surgical results of a series of patients who underwent surgical therapy for primary or secondary temporal bone tumors. PATIENTS AND METHODS Based on a retrospective review of hospital records from 1985 to 2000, 20 patients received surgical treatment for malignant tumors of the external auditory canal and the middle ear at the Department of Otolaryngology, University Medical Faculty Nis. Of these, eight patients had primary, and 12 patients had secondary temporal bone tumors. There were 16 males and four females, with a mean age of 66 years (range 37 to 79 years). Although sex distribution was nearly alike in primary tumors (5 males, 3 females), there was an overwhelming male predominance in secondary temporal bone tumors (11 males, 1 female). Primary tumors involved the middle ear or the ear canal, while secondary tumors originated from the auricle, its neighborhood, or the parotid gland. Computed tomography (CT) was used to analyze the extent of involvement (Fig. 1). Tumor staging was made according to the system proposed by Arriaga et al. in 1990 (Table 1). [4] Partial or total temporal bone resections, or a subtotal resection (petrosectomy) were performed. Additionally, all the patients received postoperative irradiation at a total dose of 6,000 cgy in 30 fractions for six weeks. Clinical characteristics, types of operations, and survival rates were analyzed and compared between primary and secondary temporal bone tumors. Statistical analysis was made using the chi-square test. RESULTS Otalgia, otorrhea or bloody otorrhea were the main complaints of patients with tumors of the external auditory canal (Table 2). Primary tumors were at an advanced stage in most of the patients, leading to destruction of the surrounding bone in four patients, involvement of the endocranium in two patients, paralysis of the facial nerve in five patients, and total hearing loss in seven patients. Diagnoses of malignant tumors were established before surgery in four Table 1. Classification of the tumors involving the external auditory meatus and the middle ear Stage Primary tumors Secondary tumors No. of patients No. of patients TNM T 1 Limited tumor without bone erosion 2 1 T 2 Local propagation through preformed pathways 3 T 3 Local involvement of the external canal and the middle ear 3 6 T 4 Erosion to the cochlea, petrous apex, dura 3 2 T 1 N 1 Stage III T 2-4 N 1 Stage IV 2 2 Clinical A Limited lesion to the auditory meatus and the middle ear, no bone erosion 2 4 B Involvement of bony structures of the meatus and the middle ear 3 6 C Involvement of the cochlea, dura, petrous apex, with a more advanced process

3 Table 2. Clinical signs and symptoms of the patients Primary tumors Secondary tumors Signs and symptoms No. of patients % No. of patients % Otorrhea Hearing loss Bleeding Pain Facial paralysis Vertigo Soft tissue involvement patients. In four patients, surgery was planned for suspected chronic otitis. Primary external auditory canal tumors and small middle ear tumors (stage A) were surgically removed using mastoidectomy. For more advanced middle ear tumors, subtotal or total petrosectomy was performed followed by irradiation (Table 3). Temporalis muscle flap was used in three cases for reconstruction and prevention of cerebrospinal fluid leakage. Histopathologic diagnoses were squamous cell carcinoma in all the cases. Secondary involvement of the bony external auditory meatus and the middle ear was the result of local invasiveness of squamous cell carcinoma (58%) or A B C D E F Fig. 1. A. Primary carcinoma; B. Intracranial propagation; C. Appearance after resection of secondary carcinoma; D and E. Appearance after subtotal petrosectomy and the use of temporalis muscle flap, F. Reconstruction after resection of secondary temporal bone carcinoma. 03

4 Temporal Bone Carcinoma: Results of Surgery for Primary and Secondary Malignancies Table 3. Operations performed Primary tumors Secondary tumors Operation No. of patients % No. of patients % Previous operation Radical trepanation Subtotal petrosectomy Total petrosectomy Parotidectomy Neck dissection Soft tissue resection Reoperation basal-cell carcinoma (42%), or inadequate surgical therapies previously performed. All the patients with secondary tumors had undergone previous operations. Secondary growths or metastases occurred mainly on one of the borders of the primary tumors, and in one case, the residual tumor was deeply situated in the meatus, together with the tympanic membrane, both covered by a local skin flap. In all the patients, surgical resection was performed depending on the extent of the tumor. Skin defects were covered with the use of local skin flaps. Significant differences were found between primary and secondary temporal bone tumors with respect to symptoms and the type of operation (p<0.05). A metastatic temporal bone tumor was encountered in a 69-year-old female patient who had had complaints of intense local pain, pressure, left hearing loss, and vertigo. She did not have a history of any previous ear disease. Twelve years before, she had gastrectomy with histologically confirmed adenocarcinoma. On otoscopy, the tympanic membrane was found intact. She had mixed hearing loss (50 to 60 db). Radiologically, there was an osteolytic area, 4x3 cm in size, involving the squamous and mastoid parts of the temporal bone. Subtotal temporal bone resection was performed and metastatic adenocarcinoma was verified. Following postoperative irradiation, she died seven months later due to intracranial extension. Five-year survival rates with respect to the pathologic extent of the lesions and involvement of tissue margins according to the clinical classification of the tumors are tabulated in Table 4. The overall five-year survival rates were 37.5% (3/8) and 58.3% (7/12) for primary and secondary temporal bone malignancies, respectively. Patients with free margins had a significantly better survival (9/11, 81.8%) than those with positive margins (1/9, 11.1%) (p<0.05). Patients with lymph node involvement had a very poor survival (19%). Local tumor recurrence was the cause of death in all the cases, the mean interval from recurrence to death being 4.1 months. The extent of surgery did not have any significant influence on the survival (p>0.05) (Table 5). Total resection of the temporal bone was not found sufficient to improve survival because of advanced tumor propagation. DISCUSSION Early detection of a primary temporal bone tumor relies on the histopathologic analysis of each tissue removed from the external canal or middle ear. This should be followed by a detailed high-resolution CT examination for documentation of bone erosion. Soft tissue changes may not be accurately demonstrated only on the basis of CT scans; thus, some cases may Table 4. Five-year survival rates according to the clinical classification of tumors Primary tumors Secondary tumors Survival in patients with Survival in patients with Classification Free % Positive % Free % Positive % groups margins margins margins margins Group A 2/ / /1 0 Group B 1/ /2 0 3/4 75 1/2 50 Group C 0/1 0 0/2 0 0/2 0 04

5 Table 5. Five-year survival rates according to the types of surgery Primary tumors Secondary tumors Operation No. of patients % No. of patients % Partial resection 1/2 50 4/5 80 Subtotal petrosectomy 2/4 50 3/7 43 Total petrosectomy 0/2 0 require magnetic resonance imaging as an adjunct diagnostic procedure. [5] Although long-standing chronic otitis media usually precedes temporal bone malignancies, this was not common for primary malignancies in this study. Otologists should bear temporal bone malignancies in mind in patients with chronic suppurative otitis media and in those presenting with suspected symptoms. [6] Extension of the tumor is associated with a higher mortality. Local invasiveness of the tumor is the most important prognostic factor. This emphasizes the need for an adequate preoperative diagnosis and a surgical technique that will enable a complete resection of the tumor with oncologically safe margins. Patterns of invasion to the temporal bone include erosions in the following directions: superiorly through the tegmen tympani into the middle cranial fossa, anteriorly into the glenoid fossa and the infratemporal space, inferiorly through the jugular foramen, posteriorly in the mastoid air cells, medially into the carotid canal, and very rarely through the otic capsule. [7] We found that invasions to the endocranium and the skull base were the most frequent and the most important localizations. Metastatic carcinoma of the temporal bone is rare and usually not recognized because it may be oligosymptomatic or overshadowed by other metastases. Another factor for underdiagnosis is that metastatic evaluation usually does not include temporal bone imaging. [8-9] Classification of temporal bone malignancies is of particular importance in planning and performing surgical treatment. They can be categorized according to the site of origin, histopathologic type, and local invasiveness of the tumor. [4] The staging system proposed by Arriaga et al. [4] for external canal tumors can also be used for middle ear tumors. This is because extension of external meatus tumors to the middle ear is almost universal, presenting with a similar mode of propagation. Surgical treatment of temporal bone malignancies is strictly dependent upon the radiological delineation of the extent of disease and its relationship to adjacent neurovascular structures. Controversy exists concerning the choice of surgical treatment. While some otologists propose a conservative approach, others support ultraradical surgery. Petrosectomy has been used in the management of carcinomas of the external ear canal and the middle ear for the past half century. The highest fiveyear survival rates have been reported with extended temporal bone resection with supraomohyoid block dissection, dural grafting and free microvascular forearm or scalp rotation flap repair. [10] Some studies reported a much better survival with radical surgery combined with radiotherapy compared to that obtained from conventional partial temporal bone resection and radiotherapy. [10-15] The importance of clinical studies that compare different classification systems of temporal bone tumors lies in better planning of surgical therapy, evaluation of the efficacy of treatment, and comparison of survival rates. Discrepant results reported concerning the five-year survival rates of temporal bone tumors as determined by the Kaplan-Meier method may arise from differences in tumor extension and the number of patients studied. [11] In general, survival of patients with tumors of the external auditory canal is twice as high as that of patients with middle ear tumors. [11] There are no randomized studies that report primary and secondary temporal bone malignancies. In general, all studies are case series. A literature review by Prasad and Janecka [16] outlined the following features concerning the surgical treatments for the temporal bone: (i) Patients with carcinoma that is confined to the external auditory canal have similar survival regardless of the surgical method employed, namely mastoidectomy, lateral temporal bone resection, or subtotal temporal bone resection. (ii) Radiation therapy following lat- 05

6 Temporal Bone Carcinoma: Results of Surgery for Primary and Secondary Malignancies eral temporal bone resection does not appear to improve survival. (iii) In patients with tumor extension into the middle ear, survival following subtotal temporal bone resection seems to be better than that following lateral resection or mastoidectomy. (iv) Radiation therapy following mastoidectomy improves survival, but its exact value remains uncertain. (v) The results of surgical resection in cases with tumor extension from the middle and inner ear to the petrous apex are poor. (vi) Resections involving the diseased dura mater, brain parenchyma, or internal carotid artery are of little or no clinical improvement. [16] Total temporal bone resection combined with postoperative radiotherapy seems to be associated with improved survival rates. However, this may not be applicable to some patients in whom total removal presents high risks, resectability of the tumor is doubtful, there is an increased risk for persistent cerebrospinal fluid leakage, or if there is endocranial propagation. On the other hand, since all parts of the temporal bone may not be affected, preservation of some bone trabecula may be advantageous in some patients. The results of this study indicate that some clinically important differences observed between primary and secondary temporal bone tumors may have significant implications. Secondary malignancies are mainly caused by locally invasive or inadequately treated tumors that occur in the neighborhood of the external meatus. Thus, their diagnosis is obvious, there is a high likelihood of previous operations, and reoperation may be necessary. Infiltration of basal-cell carcinoma is usually confined to a few sites for which reoperations are needed, and survival in these tumors is much better than that in planocellular carcinoma. In contrast to secondary malignancies, detection of primary tumors is usually incidental, initial diagnoses may often be mistaken for other lesions, and surgical treatment of these tumors is much more complicated and sometimes unrewarding. Involvement of the middle ear is followed by further propagation inside the temporal bone and adjacent vital structures, so differences in survival are within a very limited range irrespective of the stage or type of the tumor or the surgical procedure performed. In conclusion, the prognosis of carcinomas involving the temporal bone is directly related to the extent of tumoral propagation. Early diagnosis is needed for an adequate and successful therapy. Computed tomography and magnetic resonance imaging are helpful in the delineation of tumoral extension and contribute to the planning of the treatment. Appropriate selection of patients and the surgical technique, together with reconstruction, and postoperative radiotherapy may enable an improved survival and quality of life. REFERENCES 1. Hahn SS, Kim JA, Goodchild N, Constable WC. Carcinoma of the middle ear and external auditory canal. Int J Radiat Oncol Biol Phys 1983;9: Kuhel WI, Hume CR, Selesnick SH. Cancer of the external auditory canal and temporal bone. Otolaryngol Clin North Am 1996;29: Lustig LR, Jackler RK, Lanser MJ. Radiationinduced tumors of the temporal bone. Am J Otol 1997; 18: Arriaga M, Curtin H, Takahashi H, Hirsch BE, Kamerer DB. Staging proposal for external auditory meatus carcinoma based on preoperative clinical examination and computed tomography findings. Ann Otol Rhinol Laryngol 1990;99(9 Pt 1): Pensak ML, Gleich LL, Gluckman JL, Shumrick KA. Temporal bone carcinoma: contemporary perspectives in the skull base surgical era. Laryngoscope 1996;106: Savic DL, Djeric DR. Malignant tumours of the middle ear. Clin Otolaryngol 1991;16: Leonetti JP, Smith PG, Kletzker GR, Izquierdo R. Invasion patterns of advanced temporal bone malignancies. Am J Otol 1996;17: Streitmann MJ, Sismanis A. Metastatic carcinoma of the temporal bone. Am J Otol 1996;17: Weiss MD, Kattah JC, Jones R, Manz HJ. Isolated facial nerve palsy from metastasis to the temporal bone: report of two cases and a review of the literature. Am J Clin Oncol 1997;20: Tiwari R, Feenstra L, Karim A. Temporal bone resections for carcinoma of the middle ear and the external ear canal. Am J Surg 1992;164: Paaske PB, Witten J, Schwer S, Hansen HS. Results in treatment of carcinoma of the external auditory canal and middle ear. Cancer 1987;59: Gabriele P, Magnano M, Albera R, Canale G, Redda MG, Krengli M, et al. Carcinoma of the external auditory meatus and middle ear. Results of the treatment of 28 cases. Tumori 1994;80:

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