Which of the following is the most likely diagnosis? An autopsy is done on a 46-year-aid woman who died of adenocarcinoma of the colon. Examination of the neck shows a 5-cm, rounded mass next to the bifurcation of the carotid artery. A section of the mass is shown in the photomicrograph. Immunohistochemistry of the section is positive for synaptophysin, chromogranin and neuron-specific enolase_ Electron microscopy shows numerous electron-dense, membrane-bound neurosecretory granules. Examination of the adrenal glands shows no masses.
A. Metastatic colonic adenocaroinoma B. Metastatic squarnous cell carcinoma of the larynx C. Papillary carcinoma of the thyroid gland D. Paraganglioma E. Parathyroid adenoma