Macroscopy: A. Labelled "Right lung".  The pleural surface is tan to violaceous and bears scattered anthracotic pigment.  There are pale grey fibrous areas over the lateral surface of the lower lobe. No puckering is seen over the pleural surface.  Sectioning reveals a tumour obstructing and entirely occluding the main bronchus and straddling the middle and inferior lobar bronchi. The tumour is 55 x 52 x 40 mm, and is hard and white with an infiltrative border with necrosis at the lateral aspect. The tumour is centred in the superior segment of the lower lobe, and crosses the oblique fissure to involve the medial segment of the middle lobe. The tumour extends into the main bronchus, approximately 3 mm from its point of resection. It focally abuts the pleura, and appears to be approximately 40 mm from the parenchymal margin. There is bronchiectasis and obstructive change occupying the entire lower lobe, and extending to the hilum. There are fibrous/pale grey tan areas in the periphery of the lower lobe remote from the tumour. Within the upper lobe, there is patchy limited mucoid material plugging bronchi, and the tissue shows a spongy consistency possibly consistent with emphysematous change.  Within the periphery of the lower lobe there are deposits of fatty tan tissue 5-8mm. There are multiple lymph nodes within the hilar region and adjacent to the tumour, up to 20 mm in size, some of which appear to be involved by tumour. RS

B. Labelled "Right lung level 4R lymph node".  C. Labelled "Right lung level 7 lymph node". D. Labelled "Right lung level 9 lymph node". E. Labelled "Lymph node level 10 right lung". 

Microscopy:  A. Multiple sections taken through the tumour, show extensive infiltration by variably sized nests of moderate the well differentiated to poorly differentiated squamous epithelial cells with central necrosis and focal crypt 9 patient. The tumour cells infiltrate across the oblique fissure and are seen extending from the region of the main bronchus into the surrounding tissues with direct infiltration of some of the hilar lymph nodes, and direct infiltration into the outer aspect of the main pulmonary artery. The tumour occludes rhonchi within the lumen. Tumour is clear of the bronchial resection margin measured macroscopically at 3 mm. 19 lymph nodes separate to those directly infiltrated by adjacent tumour, show 2 within which there is metastatic squamous carcinoma. Other nodes, show anthracotic pigmentation. Distal to this there is bronchiectasis.

B. Multiple lymph nodes, show anthracotic pigmentation. No evidence of malignancy. C. Multiple lymph nodes, show no evidence of metastatic carcinoma. D. Sections show fragments of mature fat. E. Lymph node, showing anthracosis. No evidence of metastatic malignancy.

Conclusion: A. Right lung–55 mm poorly differentiated squamous cell carcinoma, centred on the hilum, extending from the inferior and into the middle lobe across the oblique fissure, showing vascular invasion, 3 mm clear of the bronchial resection margin, not invading the pleura, clear of all other margins with metastatic tumour present in 2/19 nodes with several nodes directly infiltrated by squamous carcinoma. Distal bronchiectasis. (2/19)

Number of lymph nodes 19 - Number of involved lymph nodes 2

Pathological staging (AJCC 8th edition) T3, N1