Beyond the usual - Atypical imaging presentation in lung cancer and implications for TNM-staging

Q: Why are atypical CT findings in lung cancer important for TNM staging?

Atypical CT appearances can be misread as benign disease or other malignancies, which may shift the TNM stage and lead to inappropriate treatment decisions.

Q: How does pneumonic-type adenocarcinoma present on CT and how is it confirmed?

It often resembles infectious pneumonia, so accurate CT evaluation and tissue sampling are needed to confirm diagnosis and staging.

Q: What challenges do lung cancers with air lucency create for volumetric assessment?

They appear as cystic, cavitary, or bullous lesions, complicating volumetric measurements; adapted TNM measurements that exclude air-space components may be beneficial.

Sep 23, 2026

Uploaded by nayy☆

Review article detailing how atypical computed tomography (CT) appearances of lung cancer span multiple diagnostic patterns and can complicate accurate staging. It highlights practical pitfalls where pneumonic-type adenocarcinoma, multifocal ground-glass/lepidic adenocarcinomas, and lung cancers with air lucency may mimic benign infections or other malignancies. The review explains why careful CT interpretation, tissue sampling, and adapted TNM measurements that exclude air-space components support correct stage assignment, and how tailored staging and management apply to pulmonary carcinoid tumors.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages8

Reading Time20 min

AccessFree to download

Purpose of review

Recent findings

Atypical adenocarcinoma patterns

Air lucency lesions and adapted TNM assessment

Pulmonary carcinoid tumors

Summary

Introduction

Role of CT in TNM staging

Typical vs atypical imaging presentations

Clinical imaging spectrum and diagnostic challenges

REVIEW UPRI RNIENTON Beyond the usual – Atypical imaging presentation in lung cancer and implications for TNM-staging Daria Kifjaka,b, Rebecca Muraa, Svitlana Pochepniaa,b, Nino Bogveradzea,b,c, Aida Korajaca, Benedikt H. Heidingera, Ruxandra-Iulia Milosa,d, Lucian Beera,b and Helmut Proscha,b Purpose of review This review illustrates the spectrum of atypical computed tomography (CT) appearances of lung cancer and provides practical guidance for accurate diagnosis and staging. Recent findings While most lung cancers show typical CT features, certain subtypes present atypically, mimicking benign conditions or other malignancies. These include pneumonic-type adenocarcinoma, multifocal adenocarcinoma with ground-glass/lepidic features, lung cancer with air lucency, and pulmonary carcinoid tumors. Pneumonic-type adenocarcinoma often resembles infectious pneumonia, requiring careful CT evaluation, and tissue sampling for confirmation. Multifocal ground-glass/lepidic adenocarcinomas, most commonly seen in female never-smokers, are indolent with low metastatic potential. Lung cancers with air lucency, appearing as cysts, cavitary, or bullous lesions, challenge volumetric assessment and may benefit from adapted TNM measurements excluding air-space components. Pulmonary carcinoid tumors show variable imaging features and require tailored staging and management based on their differentiation and spread. Summary Accurate recognition of atypical CT manifestations of lung cancer is critical to avoid misinterpretation and inappropriate management. Integrating imaging characteristics with histopathologic and, when applicable, molecular data ensures correct staging and guides personalized therapy. Keywords computed tomography, lung cancer, TNM staging INTRODUCTION Lung cancer remains the second most common malignancy and the leading cause of cancer-related deaths worldwide in 2025, accounting for a substantial global health burden despite advances in screening, diagnostic imaging, and targeted therapies [1&& ,2] . Accurate staging is crucial, as it determines both prognosis and therapeutic strategies. The TNM (tumor, nodule, and metastasis) classification is used internationally as a standard framework in lung cancer staging, with imaging, particularly computed tomography (CT), playing a central role in initial diagnosis, lesion characterization, and staging[3&&,4&] . While many lung cancers present with typical CT features that facilitate a straightforward diagnosis and staging, a subset of them may show atypical imaging appearances that may deviate from the classic presentation. These atypical manifestations can overlap with benign pulmonary conditions (e.g., infections), as well as with other malignant processes, leading to potential misinterpretation, delayed diagnosis, and staging inaccuracies [5] . Lung cancer typically presents as a solitary nodule ( <3cm) or a mass (􀀁3cm) within the lung parenchyma. Both nodules and masses may show variable shapes, including round, ovoid or polygonal, with margins ranging from well defined to irregular (e.g., lobulated and spiculated) . Whereas nodules may be a Department of Biomedical Imaging and Image-guided Therapy, bChristian Doppler Laboratory for Machine Learning Driven Precision Imaging, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, cAmerican Hospital Tbilisi, Tbilisi, Georgia and dDepartment of Diagnostic and Interventional Radiology, Clinic Donaustadt, Vienna Healthcare Group, Vienna, Austria Correspondence to Helmut Prosch, MD, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Waehringer Guertel 18–20, 1090 Vienna, Austria. Tel: +43 0 1 40400 48180; fax: +43 0 1 40400 48980; e-mail: [helmut.prosch@meduniwien.ac.at](helmut.prosch@meduniwien.ac.at) [Curr Opin Oncol](Curr Opin Oncol 2026)[ 2026](Curr Opin Oncol 2026), [38:31](38:31)–[38](38) [DOI:10.1097/CCO

FAQs

Why are atypical CT findings in lung cancer important for TNM staging?

Atypical CT appearances can be misread as benign disease or other malignancies, which may shift the TNM stage and lead to inappropriate treatment decisions.

How does pneumonic-type adenocarcinoma present on CT and how is it confirmed?

It often resembles infectious pneumonia, so accurate CT evaluation and tissue sampling are needed to confirm diagnosis and staging.

What challenges do lung cancers with air lucency create for volumetric assessment?

They appear as cystic, cavitary, or bullous lesions, complicating volumetric measurements; adapted TNM measurements that exclude air-space components may be beneficial.

Sep 23, 2026

Uploaded by nayy☆