Upper Gastrointestinal Bleed as a Manifestation of Poorly Differentiated Metastatic Squamous Cell Carcinoma of the Lung.

Gastrointestinal (GI) metastasis from primary lung cancer is a rare clinical finding. Lung cancer most often metastasizes to the brain, bone, liver, and adrenal glands; with gastrointestinal involvement being very rare. We report a case of a 39-year-old female with a diagnosis of poorly differentiated Squamous Cell Carcinoma (SCC) of the lung presenting with dizziness and melena. Esophagogastroduodenoscopy (EGD) showed a bleeding mass in the stomach. Final biopsy report and Immunohistochemistry (IHC) of the specimen were consistent with SCC lung metastasis. While it is imperative to have a high clinical suspicion for GI metastasis in patients with primary lung cancer presenting with GI symptoms, it may be challenging to establish diagnosis. Endoscopy along with pathology and immunohistochemistry play a crucial role in differentiating primary GI malignancies from metastasis.