functional neuroendocrine tumor
Neuroendocrine neoplasm that produces and secretes hormones or bioactive substances causing clinical symptoms.
Full Definition
A functional neuroendocrine tumor is a neoplasm arising from neuroendocrine cells that retains the ability to synthesize, store, and secrete bioactive hormones or peptides in quantities sufficient to produce clinical symptoms. These tumors are characterized by their capacity to cause specific hormonal syndromes related to the particular substances they produce, such as insulin-induced hypoglycemia in insulinomas or serotonin-related carcinoid syndrome. The functional activity may be continuous or episodic, and the clinical presentation often provides important clues for diagnosis. Functional tumors typically require both anatomical localization and biochemical characterization for optimal management, and they may respond to specific medical therapies targeting hormone excess.
Usage
Usage note: Always specify the hormone or bioactive substance produced when describing functional activity.
In Context
- "The patient's episodic flushing and diarrhea were caused by a functional neuroendocrine tumor secreting vasoactive intestinal peptide." — clinical case report
- "Biochemical testing confirmed the diagnosis of a functional neuroendocrine tumor based on elevated chromogranin A and specific hormone levels." — diagnostic report