Lung cancer metastasis to the gastrointestinal system: An enigmatic occurrence

Figure 1 Computed tomography chest showing lung opacity, pleural effusion and lymph nodes.

Figure 2 Magnetic resonance imaging showing multiple metastatic liver lesions.

Figure 3 Gastric ulcer in the body.

Figure 4 Rectal mass.

Figure 5 Pathology from both rectal mass and gastric ulcer showed metastatic adenocarcinoma, consistent with lung primary. A: Gastric mucosa with metastatic adenocarcinoma; B: Rectal mass showing submucosa and deep mucosa with metastatic adenocarcinoma.

Figure 6 Immunohistochemical staining. A: Gastric biopsy showing positivity to CK 7; B: Gastric biopsy showing positivity to Napsin-A; C: Gastric biopsy showing positivity to TTF-1; D: Rectal biopsy showing positivity to CK 7; E: Rectal biopsy showing positivity to Napsin-A; F: Rectal biopsy showing positivity to TTF-1. CK 7: Cytokeratin 7; TTF-1: Thyroid transcription factor-1.