Herein, we report the case of a 42-year-old male patient diagnosed with adenocarcinoma with different histomorphologies in the primary lung site (mucinous type) and lymph node metastasis (solid type), of the same genotype, both presenting with ALK rearrangement but negative for EGFR mutation.
In patients with completely resected stage IA lung adenocarcinoma, ALK rearrangement was associated with unfavorable DFS and more frequent regional lymph node metastasis.
In addition, the ALK gene translocations were evaluated in a series of 53 primary tumours and their paired lymph node metastases using ALK D5F3 IHC staining.
In two patients with adenocarcinoma of the lung driver mutations were detected (EGFR Exon 19 deletion and ALK rearrangement) out of the lymph node metastasis.
The findings suggested that patients with ALK rearrangements are more likely to be young, have EGFR wild-type, and more likely to exhibit mucus secretion, solid tumor growth, lymph node metastasis and pleural metastasis.
Adenocarcinomas with ALK rearrangement appeared as solid masses with lobulated margins at CT and were more likely to be associated with lymphangitic metastasis, advanced lymph node metastasis, and pleural or pericardial metastasis than were tumors with EGFR mutations.
Compared with the entire group of patients, ALK translocation-positive patients were younger (P < .01) and more likely to be nonsmokers (P = .017), but presented with a higher percentage of advanced-stage disease (P = .022) and lymph node metastases (P = .006).