Lung cancer metastasis to the gastrointestinal system: An enigmatic occurrence

Table 1 Reported cases of metastatic lung cancer to the colon

Ref.	Histology	Prior diagnosis of lung malignancy	Presenting clinical scenario
Jevremovic et al[13], 2016	Adenocarcinoma	New diagnosis	Iron deficiency anemia
Miyazaki et al[15], 2015	Squamous cell	Known case	Abdominal pain and anemia
Kaswala et al[14], 2013	Adenocarcinoma	Known case	Surveillance colonoscopy
Sakai et al[16], 2012	Squamous cell	Known case	Abdominal pain
Hirasaki et al[17], 2008	Squamous cell	Diagnosed at the same time	Asymptomatic with positive fecal occult blood testing.
Yang et al[2], 2006	Squamous cell	Known case	Bloody stools
Stinchcombe et al[18], 2006	Squamous cell	Diagnosed at the same time	Asymptomatic with positron emission tomography computer tomography scan done showing increased colonic uptake
Habeşoğlu et al[19], 2005	Squamous cell	Cancer naive	Bowel obstruction
Carroll et al[20], 2001	Squamous cell	Cancer naive	Weight loss and diarrhea
Bastos et al[21], 1998	Squamous cell	Known case	Abdominal pain, diarrhea and bloody stools
Gitt et al[22], 1996	Squamous cell	Known case	Bowel perforation
Gateley et al[23], 1993	Squamous cell	Known case	Gastrointestinal bleeding
Brown et al[24], 1980	Anaplastic carcinoma	Diagnosed at the same time	Abdominal pain, weight loss
Smith et al[25], 1978 (2 cases)	Histology not known	Not known	Intermittent obstruction, bleeding or anemia