Knowra Hamartoma Hamartoma A hamartoma is a benign, disorganized overgrowth of mature tissues normally present at the affected site. Unlike a true neoplasm, it is composed of native tissue elements arranged abnormally.
Neoplasm : An abnormal mass of tissue whose growth exceeds and persists beyond normal tissue growth, often forming a tumor. A neoplasm is defined by autonomous growth, unlike the disorganized native tissues of a hamartoma.
Histopathology : The microscopic study of diseased tissues, especially their structure and cellular changes. Microscopic examination reveals the disorganized arrangement that defines a hamartoma.
Pulmonary hamartoma : A benign lung nodule composed chiefly of cartilage, connective tissue, and other native pulmonary elements. It is a common example of a hamartoma detected as a lung mass.
PTEN : A tumor-suppressor gene encoding a phosphatase that restrains the PI3K–AKT–mTOR signaling pathway. PTEN loss can drive hamartoma formation in inherited syndromes such as Cowden syndrome.
Mass effect : Damage or symptoms caused when a lesion compresses or displaces nearby structures. A benign hamartoma can cause serious problems by pressing on critical anatomy.
Choristoma : A mass of normal tissue located at an abnormal site. A choristoma contains normal tissue in the wrong location; a hamartoma contains native tissue in its usual location.
Tissue : A group of cells and extracellular material organized to perform a function. Hamartomas consist of mature tissue types that normally occur at their site.
Hypothalamic hamartoma : A congenital, non-neoplastic mass of disorganized neuronal and glial tissue in the hypothalamus. Its location can cause gelastic seizures and precocious puberty.
PI3K–AKT–mTOR pathway : A cell-signaling network that regulates growth, metabolism, survival, and protein synthesis. Excess signaling through this pathway contributes to hamartomatous lesions in several genetic disorders.
Seizure : A transient episode of abnormal electrical activity in the brain causing changes in movement, sensation, or awareness. Hypothalamic hamartomas can provoke characteristic gelastic seizures.
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