All of the following are helpful for diagnosis of medullary Ca thyroid except -
Important Diagnostic Features of Medullary carcinoma are :
Acellular amyloid deposition.
Calcitonin secretion by tumour cells.
Microscopically polygonal to spindle cell may form nests, trabeculae and even follicles.
Electron Microscopy showing variable no. of electron-dense granules (Membrane-bound) within the cytoplasm.
Spindle cell stroma with few follicles
Amyloid deposition
Calcitonin in stroma
Histological mitochondria is essential for diagnosis