A 40-year-old male presented with a thyroid swelling and dysphagia. He gave history of on and off watery diarrhea. Biopsy of the lesion is shown. What is your diagnosis?

Ans. (c) Medullary Ca thyroid*Diarrhea in thyroid tumor can be a paraneoplastic syndromes due to VIP in a case of medullary Ca thyroid. Histology demonstrates abundant deposition of amyloid, visible here as homogeneous extracellular material, derived from calcitonin molecules secreted by the neoplastic cells.