A 64-year-old woman complains of intermittent abdominal discomfo in the right iliac fossa along with loss of appetite and significant weight loss over 6 months. She was managed conservatively. She presented 2 days later with a cramping abdominal pain at the same location along with diarrhoea. During these episodes her husband has commented that she looked red in the face. CECT abdomen was done. Which of the following tumour markers can be seen raised in the above condition: -

This is a case of carcinoid syndrome. Image 2 shows liver metastasis from the neuroendocrine tumour. Diarrhea is the most common and earliest symptom. Others include flushing, right hea failure, pain and bronchospasm. It can occur as a paraneoplastic syndrome in the context of a carcinoid tumor, most commonly a gastrointestinal tract carcinoid. The presence of the carcinoid syndrome often indicates hepatic metastatic disease, usually from a primary bowel carcinoid tumor. Histologically, carcinoids are composed of islands, trabeculae, strands, glands, or sheets of uniform cells with scant, pink granular cytoplasm and a round to oval stippled nucleus. Immunohistochemical stains are typically positive for endocrine granule markers, such as synaptophysin and chromogranin A.