The contribution of CT and MRI in staging, treatment planning and prognosis prediction of malignant tumors of external auditory canal

The international expert consensus on management of external auditory canal carcinoma

PURPOSE

The objective of this consensus is to provide otolaryngologists with appropriate strategies in the management of external auditory canal (EAC) carcinoma.

METHODS

In the absence of randomized controlled trials, the consensus is based on expert opinions utilizing the Rand/UCLA appropriateness method [Fitch and Aguilar in The RAND/UCLA appropriateness method user's manual, RAND Corporation, Santa Monica, CA, 2001], drawing from existing literature and clinical experience.

RESULTS

The management recommendations are structured around 12 key areas, including: definition and pathology, pathogenesis, clinical manifestations, work-up, tumor staging system, surgical management of primary tumor, surgical management of the parotid gland and the temporomandibular joint, lymph node metastasis, radiotherapy, chemotherapy, reconstruction, and follow-up.

CONCLUSION

Management strategies for EAC carcinoma rely on tumor extension and histopathological features. Surgical removal with free surgical margins or combination with radiotherapy, chemotherapy are most often the best options. Given the rarity of the disease, prospective, randomized, multi-institutional clinical trials should be designed to enable reliable comparisons of the outcomes of EAC carcinoma treatments, thereby providing evidence-based clinical data to establish widely accepted guidelines. It emphasizes the need for a multidisciplinary team to be involved in the management of EAC carcinoma, and regular follow-up should be implemented postoperatively.

Survival Outcomes in Squamous Cell Carcinoma of the External Auditory Canal: A Systematic Review and Meta-Analysis

Squamous cell carcinomas (SCC) of the external auditory canal (EAC) are rare tumors representing a surgical challenge. Current knowledge is based largely on case series; thus, the level of evidence is weak. This study sought to systematically review the available SCC of the EAC literature and to identify risk factors for overall survival (OS) and disease-specific survival (DSS). A systematic review and meta-analysis of papers searched up to December 2022 through PubMed, Scopus, Web of Science, and Cochrane Library databases was conducted. Quality assessment of the eligible studies was done according to the Newcastle-Ottawa Scale. Pooled univariate and multivariable analyses and meta-analysis using a random-effects or fixed-effects Mantel-Haenszel model were performed. Fifteen articles (282 patients) met the inclusion criteria and were included in the quantitative analysis. The pooled multivariable analysis revealed cT3 and cT4 as independent prognostic factors for OS (p = 0.005, and p < 0.001, respectively) and DSS (p = 0.002, and p < 0.001, respectively). Local recurrence rate was 32.3%. The meta-analysis estimated significantly higher odds ratios for advanced T categories, than cT1-T2 tumors for OS and DSS (OR = 3.55; 95% CI, 1.93–6.52, and OR = 3.73; 95% CI, 2.00–6.97, respectively). In conclusion, locally advanced tumors were associated with poor prognosis. Poor outcomes mostly occurred due to local recurrence.

Long-term analysis of prognostic risk factors impacting surgical outcomes in patients with external auditory canal carcinoma

BACKGROUND

Malignant neoplasms of the external auditory canal (EAC) are rare. No consensus on management has emerged.

OBJECTIVE

To determine possible risk factors influencing tumorgenesis and prognosis of EAC carcinoma.

MATERIALS AND METHODS

108 patients (87 men/21 women) with an average age of 74 ± 13.8 years were recruited from 2005 to 2019 at Department of Otorhinolaryngology, Head and Neck Surgery Heidelberg. The follow-up interval was 43.62 ± 55.39 months. Partial and (sub)total ablative otis, supplementary surgery (petrosectomy, parotidectomy, neck dissection, mastoidectomy) and adjuvant radio(chemo)therapy belonged to treatment options. TNM status was determined at time of diagnosis using the AJCC staging system.

RESULTS

63.9% of patients underwent a total ablative otis. Tumor recurrence was seen in 24.1%. The 1-year survival rate was 87%, the 5-year survival rate was 52%, the mean overall survival (OS) was 3.82 ± 4.6 years. Male EAC carcinoma patients had a better OS (p < 0.001), PFS (p < 0.001) and DSS (p = 0.02) than females. T1 patients had a better OS (p = 0.01), PFS (p = 0.01) and DSS (p < 0.001) than T4 patients. Lymph node but not distant metastasis, tumor grading, perineural, venous and lymphatic invasion, histology, age and tumor localization influenced the OS in EAC carcinoma patients (p = 0.04). The more radical the ablative otis, the worse the OS (p = 0.002), PFS (p = 0.02) and DSS (p < 0.001). Radio(chemo)therapy did not improve the OS.

CONCLUSIONS

EAC carcinoma are difficult to treat and benefit from early diagnosis so that a radical combined treatment approach does not need to be used.

[Current status of the diagnosis and treatment of temporal bone squamous cell carcinoma]

Temporal bone squamous cell carcinoma, which is rare in the clinical setting, is the most common type of temporal bone malignancy. Its rarity makes the staging, the way of temporal bone resection, the management of parotid gland and cervical lymph node, and the application of radiotherapy and chemotherapy still controversial.There is no unanimous consensus and guideline about it to date at home and abroad.This paper reviewed the recent advance in the diagnosis and treatment of temporal bone squamous cell carcinoma in the hope of providing some help and reference for the management of the disease.

Imaging the External Ear: Practical Approach to Normal and Pathologic Conditions

The external ear (EE) is an osseous-cartilaginous structure that extends from the auricle to the tympanic membrane. It is divided into two parts: the auricle (or pinna) and the external auditory canal (EAC). Given the ease of access to the EE, imaging studies are not always needed to make a diagnosis. However, when lesions block visual access to areas deep to the EE abnormality, complications are suspected, or there is lack of response to treatment, imaging becomes essential. A basic understanding of the embryologic development and knowledge of the anatomy of the auricle and EAC are useful for accurate diagnosis of EE lesions. Congenital, traumatic, inflammatory, neoplastic, and vascular conditions can affect the EE. An overview of the anatomy and embryologic development of the EE is presented, with discussion and illustrations of common and uncommon conditions that affect EE structures and a focus on the CT and MRI features that are of interest to radiologists. CT is usually the first diagnostic modality used to evaluate the EAC and is the superior method for demonstrating bone changes. MRI provides excellent tissue characterization and enables one to better define lesion extension and perineural tumor spread. In addition, a flowchart to facilitate the differential diagnosis of EE abnormalities is provided. Online supplemental material is available for this article. ^©RSNA, 2022.

Treatment Strategies for Malignancies of the External Auditory Canal

Malignant tumors of the external auditory canal (EAC) are rare tumors in the head and neck. Delayed diagnosis is not uncommon because the symptoms of early tumors are nonspecific. Various surgical and oncological treatment modalities have been reported. Decision-making depends on pathological feature and stage of the lesions, patient’s general condition and preference, and physician’s experience and skill. Radical surgery is widely accepted as the primary treatment of choice. Postoperative radiotherapy is used more often to improve local and regional control of the disease. Chemotherapy is usually recommended for advanced disease, residual disease, and metastasis. Prognosis is affected by multiple factors such as TNM stage, surgical margin, pathological type and differentiation of tumor, involvement of facial nerve, and so on. Although the survival rate is improved significantly over the past several decades with the development of skull base surgery, neuroradiology, anesthesiology, and oncology, it remains challenging to diagnose and treat EAC malignancies due to the rarity, the local anatomical complexity of temporal bone, and the lack of standard TNM staging system.

Evaluation of the modified Pittsburgh classification for predicting the disease-free survival outcome of squamous cell carcinoma of the external auditory canal

Background

Squamous cell carcinoma (SCC) of the external auditory canal (EAC) is a rare disease, which is commonly classified with the modified Pittsburgh classification. Our aim was to evaluate the predictive performance of this classification in relation to disease‐free survival (DFS).

Methods

We examined retrospective data from a nationwide Dutch cohort study including patients with primary EAC SCC. These data were combined with individual patient data from the literature. Using the combined data, the predictive performances were calculated using the c‐index.

Results

A total of 381 patients were included, 294 for clinical and 281 for the pathological classification analyses. The c‐indices of the clinical and the pathological modified Pittsburgh classification predicting DFS were 0.725 (0.668‐0.782) and 0.729 (0.672‐0.786), respectively.

Conclusion

The predictive performance of the modified Pittsburgh classification system as such appears to be acceptable to predict the DFS of EAC SCC. Other factors need to be added to a future model to improve the predicted performance.

Data Set for the Reporting of Ear and Temporal Bone Tumors: Explanations and Recommendations of the Guidelines From the International Collaboration on Cancer Reporting

The International Collaboration on Cancer Reporting (ICCR) was established to internationally unify and standardize the pathologic reporting of cancers based on collected evidence, as well as to allow systematic multi-institutional intercountry data collection to guide cancer care in the future. Such collaborative efforts are particularly essential for developing an evidence base for rare neoplasms or those with marked geographic variation in incidence, such as the tumors of the ear and the temporal bone. The ear and the temporal bone, including the external auditory canal and the middle and inner ear, with the closely associated facial nerve, internal carotid artery, and internal jugular vein, is one of the most complex anatomic structures in the head and neck. A wide range of benign and malignant neoplasms arise in this region. The management of these neoplasms involves complex surgery because of the anatomic confines, and as such, both benign and malignant tumors are included in this data set, as the oncologically equivalent management requires a multidisciplinary approach and standardized nomenclature and terminology. Surgical procedures at this site result in multifaceted 3-dimensional specimens that can be difficult to handle at macroscopic exam. A comprehensive macroscopic examination is important for identifying critical prognostic factors and often requires clinical and radiologic correlation. Histologic examination is straightforward for basal cell or squamous cell carcinoma but can be quite challenging for other neoplasms. A summary of the ICCR guidelines for ear tumors is presented, along with discussion of the salient evidence and practical issues.

Squamous Cell Carcinoma of the External Auditory Canal and Temporal Bone: An Update

Squamous cell carcinoma (SCC) is the most common primary malignancy to affect the temporal bone, including primary cutaneous SCC of the pinna, external auditory canal, middle and inner ear. This anatomically complex region generates complicated three-dimensional specimens that can be a challenge for macroscopic and microscopic pathologic assessment. A universally accepted staging classification for these malignancies is still to be established. A brief summary of the regional anatomy, etiology and epidemiology, presentation and diagnosis, radiologic assessment and treatment follows with a review of the pathologic assessment of the different types of specimens generated and an update on staging for SCC of the temporal bone.