Macroscopy: Right lung biopsy - 6 pale tan needle core fragments 3-11 mm.
Microscopy: Sections core biopsy shows of fibrous tissue infiltrated by nests of atypical epithelial cells interspersed with areas of necrosis. Keratinisation or gland formation are not seen. Lymphovascular or perineural invasion are not identified. The tumour cells are immunoreactive with p40, no reactivity is seen in the tumour cells with TTF-1 or CD45.
Conclusion: Non-small cell carcinoma, favour squamous cell carcinoma.
Addendum: No variant was detected in exon 18 - 21 of EGFR gene. Absence of an EGFR variant is associated with decreased sensitivity to EGFR tyrosine kinase inhibitors such as erlotinib and gefitinib (Mok et al NEJM 2010; 361:947-57)
No mutation detected, EGFRWT.