Case Report

Early Gastrointestinal Progression to Immunotherapy in Lung Cancer: A Report of Two Cases

Figure 3

Intestinal biopsy: normal colonic mucosa infiltrated by solid-pseudoglandolar carcinoma, positive for CK7 and negative for intestinal differentiation markers, such as CK20 and CDX2 (arrows). Lung adenocarcinomas with prevalent solid pattern may be negative for TTF-1 but often positive for CK7. On the basis of the morpho-immunohistochemical data and clinical history, the diagnosis of intestinal metastasis of lung adenocarcinoma was made.