Macroscopy: Labelled "Right lower lobe". Right lower lobe weighing 121 g measuring 158 x 125 x 90 mm. Pleura appears pale tan/brown and grey with a smooth texture. Stapled margin inked green and hilum black and sectioned from superior to inferior into 13 slices. Within slices 3 and 4 there is a subpleural firm cream lesion measuring 12 x 8 x 5 mm. Lesion is 15 mm clear of the stapled margin and greater than 20 mm from the hilar margin. There is no invasion into large airways or vessels. There is no extension through the pleural surface. Pleura is inked blue at area of lesion. 3 potential lymph nodes ranging from 3–5 mm appear carbon pigmented. The remainder of parenchyma appears brown/tan. No thrombi are identified.
Microscopy: Sections through the pulmonary parenchyma show an 8 mm lesion within which a population of atypical non-mucinous epithelial cells show a predominantly lepidic pattern of growth. The cells have enlarged, hyperchromatic, ovoid nuclei with moderate amounts of eosinophilic cytoplasm showing a hobnail appearance. The cells are arranged in pseudostratified files over alveolar septa. Centrally, over less than 5 mm in linear extent, the tumour shows papillary and acinar growth patterns. The lesion is confined to the pulmonary parenchyma, showing no extension through the pleura, and lies clear of parenchymal resection margins. Angiolymphatic invasion is not identified. Anthracotic hilar lymph nodes show no evidence of metastatic malignancy.
Diagnosis: Right lower lobectomy specimen: Minimally invasive adenocarcinoma, non-mucinous, of lung.
- 8 mm in maximum dimension
- lepidic pattern predominant
- secondary papillary and acinar patterns, no more than 5 mm in maximum extent
- no necrosis
- no angiolymphatic invasion
- no pleural invasion
- clear of margins
- no malignancy in four hilar lymph nodes