Age- and gender-specific disease distribution and the diagnostic accuracy of CT for resected anterior mediastinal lesions.

Ju Gang Nam,Soon Ho Yoon,Chang Min Park,Jin Mo Goo,Chang Hyun Lee,Hyun‐Ju Lee

doi:10.1111/1759-7714.13081

Ju Gang Nam, Soon Ho Yoon + Show 4 more

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https://doi.org/10.1111/1759-7714.13081

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Abstract

BackgroundAnterior mediastinal lesions account for approximately half of all mediastinal masses and computed tomography (CT) is known to exhibit limited differentiating performance. Our aim was to evaluate the age‐ and gender‐specific distribution of anterior mediastinal lesions and the diagnostic accuracy of multi‐detector CT (MDCT).MethodsThis retrospective study included 549 consecutive patients with proven anterior mediastinal lesions and diagnostic MDCT scans. The age‐ and gender‐specific distribution of proven diagnoses and diagnostic accuracy were reviewed. The CT features of malignant and benign diseases having the lowest accuracy were compared with those of the most commonly misdiagnosed diseases.ResultsThe proportion of malignancy showed a V‐shape relationship with age (lowest, 52.7% [50s]). The most prevalent malignancies were lymphoma (20s), lymphoma/thymoma (30s), thymoma (40s–50s), and thymoma/thymic carcinoma (≥60s). The most prevalent benign diseases were thymic remnant/hyperplasia (20s–30s), and thymic bed cyst (≥40s). The first‐choice diagnostic accuracy of MDCT decreased with age regardless of gender: 75.4% (20s), 75.0% (30s), 67.8% (40s), 58.5% (50s), and 53.4% (≥60s), primarily due to incorrect diagnoses of thymic bed cyst and thymic carcinoma (accuracy, 42.3% and 30.5%), which were prevalent in older patients and mostly misdiagnosed as thymoma. The most powerful differentiating MDCT features were water attenuation (≤20 HU) (OR, 42.7 [95%CI, 8.8–‐208.3], P < 0.001) for thymic bed cyst and mediastinal lymphadenopathy (6.8 [1.7–27.2], P = 0.006) for thymic carcinoma, but both showed low sensitivity (34.5% and 18.6%, respectively).ConclusionsMDCT accuracy depended on age, owing to the age‐specific distribution of thymic carcinoma and thymic bed cyst, which frequently lacks distinguishable CT features from thymoma.

Highlights

Anterior mediastinal lesions account for approximately half of all mediastinal masses,[1,2] which include various disease entities from benign cysts to cancers.[3,4] Computed-tomography (CT) has been conventionally used for primary evaluation of anterior mediastinal lesions, but is known to exhibit limited differentiating performance
The distribution of anterior mediastinal lesions depends on age and gender[3] and chest computed tomography (CT) scan is primarily obtained on multi-detector CT (MDCT) scanners in current routine practice
According to a pathologic database search performed by the study coordinator (J.G.N.), patients who met the following inclusion criteria were included (Fig 1): (i) pathologically proven anterior mediastinal lesion between January 2006 and November 2014; (ii) multidetector CT (MDCT) images obtained with the standardized protocol for chest CT; (iii) a mean interval between pathologic diagnosis and MDCT of no longer than 1.5 months; and (iv) no history of previous treatment such as chemotherapy

Summary

Introduction

Anterior mediastinal lesions account for approximately half of all mediastinal masses,[1,2] which include various disease entities from benign cysts to cancers.[3,4] Computed-tomography (CT) has been conventionally used for primary evaluation of anterior mediastinal lesions, but is known to exhibit limited differentiating performance. The previous study reported that single-channel chest CT offers modest diagnostic accuracy, with a correct first-choice diagnosis of 61% (95% CI, 52–69%; 78/126).[2] As a result, some anterior mediastinal pathologies. The first-choice diagnostic accuracy of MDCT decreased with age regardless of gender: 75.4% (20s), 75.0% (30s), 67.8% (40s), 58.5% (50s), and 53.4% (≥60s), primarily due to incorrect diagnoses of thymic bed cyst and thymic carcinoma (accuracy, 42.3% and 30.5%), which were prevalent in older patients and mostly misdiagnosed as thymoma. Conclusions: MDCT accuracy depended on age, owing to the age-specific distribution of thymic carcinoma and thymic bed cyst, which frequently lacks distinguishable CT features from thymoma

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