Sarcomatoid Carcinoma of the Lung With Gastrointestinal Metastasis Causing Small Intestinal Obstruction: A Rare Case of Acute Surgical Emergency.

Pulmonary sarcomatoid carcinomas (PSCA) are a rare subset of Non-Squamous-Cell Lung Carcinoma (NSCLC), the most common pathological subtype of lung cancers which are the most common malignancy in the world. These rarest of rare tumours may have gastrointestinal metastasis and present as an acute abdominal surgical emergency with bowel obstruction or bleeding, as in our patient, who did not have a diagnosis of lung cancer till then. Use of novel immunohistochemistry markers like thyroid transcription factor-1 (TTF-1) may help diagnose the site of the primary tumour with accuracy in this clinical setting. Further evaluation of these patients with positron emission tomography (PET) scans helps determine the tumour burden and degree of dissemination. The aim of this article is to emphasize this rare presentation which may be unsuspected as a cause of bowel obstruction by surgical teams on the acute surgical take due to its rarity. It is vital that nihilism is avoided in these patients as a subset of these patients can still be offered curative metastectomy and treatment of the primary tumour with reasonable outcomes.