Unusual lung tumors-from morphology to genetics

Unravelling switch/sucrose non-fermentable (SWI-SNF) complex-deficient thoracic tumours: a clinicopathological comparative on undifferentiated tumours and non-small cell lung carcinomas with BRG1 and BRM deficiency

AIMS

This study was undertaken to compare and expand the clinicopathological characteristics of SMARCA4-deficient thoracic undifferentiated tumour (SMARCA4-dUT) and switch/sucrose non-fermentable-deficient non-small cell lung carcinomas (SWI/SNF-dNSCLC) and to address cases with intermediate features.

METHODS

The pathology department archive was searched for all primary mediastinal, pleural and lung-based malignancies that showed aberrant expression of two SWI/SNF proteins the Brahma (BRM) aka SMARCA2 and/or (Brahma-related gene 1 (BRG1) aka SMARCA4. Patient demographics, treatment and clinical outcomes were collected from records and telephonic interviews. Differences in histopathological features and immunohistochemical stains were analysed. Cases with characteristics intermediate between both tumour entities were sequenced to advance our understanding of their biology and to assign them a more accurate classification.

RESULTS

We identified 50 tumours with SMARCA4 and/or SMARCA2 deficiencies, including 23 (46%) SMARCA4-dUT, 18 (36%) SMARCA4-dNSCLC and 2 (4%) SMARCA2-dNSCLC. Dyscohesive or undifferentiated cellular morphology versus frank gland formation along with keratin, claudin-4 and expression of >1 stem cell marker helped classify the SWI/SNF deficient tumours as SMARCA4-dUT or SWI/SNF-dNSCLC (p<0.05). Seven (14%) cases with BRG1 deficiency displayed 'intermediate' features of both SMARCA4-dNSCLC and SMARCA4-dUT and had the shortest overall survival. The smoking-related gene signature was observed on sequencing in all four cases examined.

CONCLUSION

Tumours with intermediate features between SMARCA4-dUT and SWI/SNF-dNSCLC exist and portend an equally poor prognoses. Immunostains, including keratin, claudin-4, TTF1, HepPar1, stem cell markers, along with BRG1 and BRM testing, are essential adjuncts to morphology, while molecular studies can offer supplementary evidence in challenging cases.

Artificial intelligence for diagnosis and predictive biomarkers in Non-Small cell lung cancer Patients: New promises but also new hurdles for the pathologist

The rapid development of artificial intelligence (AI) based tools in pathology laboratories has brought forward unlimited opportunities for pathologists. Promising AI applications used for accomplishing diagnostic, prognostic and predictive tasks are being developed at a high pace. This is notably true in thoracic oncology, given the significant and rapid therapeutic progress made recently for lung cancer patients. Advances have been based on drugs targeting molecular alterations, immunotherapies, and, more recently antibody-drug conjugates which are soon to be introduced. For over a decade, many proof-of-concept studies have explored the use of AI algorithms in thoracic oncology to improve lung cancer patient care. However, despite the enthusiasm in this domain, the set-up and use of AI algorithms in daily practice of thoracic pathologists has not been operative until now, due to several constraints. The purpose of this review is to describe the potential but also the current barriers of AI applications in routine thoracic pathology for non-small cell lung cancer patient care and to suggest practical solutions for rapid future implementation.

Bronchiolar adenoma/ciliated muconodular papillary tumour: advancing clinical, pathological, and imaging insights for future perspectives

Bronchiolar adenoma/ciliated muconodular papillary tumour (BA/CMPT) is a benign peripheral lung tumour composed of bilayered bronchiolar-type epithelium containing a continuous basal cell layer; however, the similarities in imaging and tissue biopsy findings at histopathology between BA/CMPT and malignant tumours, including lung adenocarcinoma, pose significant challenges in accurately diagnosing BA/CMPT preoperatively. This difficulty in differentiation often results in misdiagnosis and unnecessary overtreatment. The objective of this article is to provide a comprehensive and systematic review of BA/CMPT, encompassing its clinical manifestations, pathological basis, imaging features, and differential diagnosis. By enhancing healthcare professionals' understanding of this disease, we aim to improve the accuracy of preoperative BA/CMPT diagnosis. This improvement is crucial for the development of appropriate therapeutic strategies and the overall improvement of patient prognosis.