Synaptophysin
Pronunciation: sy-NAP-toe-FY-sin
A neuroendocrine marker protein used in immunohistochemistry to diagnose and classify neuroendocrine tumors.
Full Definition
Synaptophysin is a glycoprotein found in presynaptic vesicles and neuroendocrine secretory granules. In pathology, it serves as a key immunohistochemical marker for confirming neuroendocrine differentiation in tumors. Along with chromogranin A and CD56, synaptophysin is part of the standard panel used to diagnose neuroendocrine tumors. Positive synaptophysin staining supports the diagnosis of NET, though the intensity and pattern of staining can vary. The marker is generally more consistently positive than chromogranin A, especially in poorly differentiated tumors, making it valuable for diagnostic confirmation.
Usage
Usage note: Often abbreviated as SYP in pathology reports; maintain consistency in abbreviation use.
In Context
- "Immunohistochemistry showed strong and diffuse synaptophysin positivity throughout the tumor cells." — Pathology report
- "The neoplasm was positive for synaptophysin and chromogranin A, confirming neuroendocrine differentiation." — Diagnostic interpretation