MACROSCOPIC DESCRIPTION: The specimen consists of a right lower and middle lung lobe with the lower lobe measuring 140 x 140 x 135 mm. The middle lobe measures 150 x 70 x 50 mm. There are three areas of pleural disruption within the lower lobe with the first lying 27 mm from the hilum and measuring 40 x 10mm. The second area lies antero-inferiorly and measures up to 55mm in extent. The third area of disruption is present laterally and measures up to 25mm in extent. The middle lobe is intact. At the bronchial resection margin, a firm cream tumour is seen partially obstructing the bronchus. The cut surface of the lower lobe shows a centrally located solid cream tumour with patchy haemorrhage measuring 50 x 37 x 55 mm. Distal to this, there is a large cavitating area filled with haemorrhage and purulent exudate and measuring 80 x 43 x 85 mm. The cavity extends to communicate with the lateral and central pleural defects. The tumour appears to expand and distort the visceral pleura but does not clearly invade through it. The tumour does not extend to involve the middle lobe.
MICROSCOPIC DESCRIPTION: Sections from the right lower lung lobe show a 55mm poorly differentiated squamous cell carcinoma centred towards the hilar region. The tumour comprises islands and nests of pleomorphic tumour cells that are supported by a dense desmoplastic stroma. The tumour cells have large, irregularly circumscribed, nuclei with large eosinophilic nucleoli and a moderate amount of eosinophilic cytoplasm. There are scattered foci of intracytoplasmic keratin. Large areas of tumour necrosis are present, together with abundant atypical mitotic figures. Tumour cells are TTF-1 negative and p40 positive by immunohistochemistry. There is perineural invasion. Tumour also invades the wall of elastic arteries. The tumour appears to invade the visceral pleura in one focus and this is confirmed on an elastin stain. There are five hilar lymph nodes, one containing metastatic carcinoma. The adjacent non-neoplastic lung has abscess formation, necrosis and organising fibrosis. Sections from the middle lobe show a pleuritis but no evidence of malignancy.
Diagnosis: Right lower and middle lung lobes: Poorly differentiated squamous cell carcinoma, right lower lobe:
- 55mm maximum extent
- Perineural invasion
- Invasion through visceral pleura
- 1/5 hilar lymph nodes contain metastatic carcinoma
- Does not extend to right middle lobe
- Adjacent cavitation, abscess and fibrosis
Pathology specimens and report courtesy Department of Pathology, The Royal Melbourne Hospital.