Objective: Invasive mucinous adenocarcinoma (IMA) is a variant of lung adenocarcinoma. We present one case of IMA with mixed mucinous and non-mucinous components, suggesting stepwise progression within the tumor.
Material and method: The two different components of IMA were separately examined by immunohistochemistry and performed amplicon sequencing (Ion Ampliseq Cancer Hotspot Panel v2, ilumina, San Diego, CA).
Result: Macroscopically, the IMA contained a small and well demarcated solid part. Tumor cells in the main part showed abundant intracytoplasmic mucin, whereas those in the solid part showed scant intracytoplasmic mucin and high-grade nuclear atypia. Both parts harbored the same KRAS p.G12 V mutation. The amplicon sequencing of the IMA showed oncogenic TP53 p.P278 L mutation was detected only in the solid part.
Conclusion: Oncogenetic TP53 mutation might promote stepwise progression of this case of IMA.
Keywords: Invasive mucinous adenocarcinoma (IMA); KRAS mutation; Stepwise progression; TP53 mutation.
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