hamartoma

A focal malformation that resembles a neoplasm, grossly and even microscopically, but results from faulty development in an organ; composed of an abnormal mixture of tissue elements, or an abnormal proportion of a single element, normally present in that site, which develop and grow at virtually the same rate as normal components, and are not likely to result in compression of adjacent tissue (in contrast to a neoplasm). [G. hamartion, a bodily defect, + -oma, tumor]

- fibrous h. of infancy a tumor appearing usually in the upper arm or shoulder in the first two years of life and consisting of cellular fibrous tissue infiltrating the subcutis.

- pulmonary h. h. of the lung, producing a coin lesion composed primarily of cartilage and bronchial epithelium.

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ham·ar·to·ma .ham-.ar-'tō-mə n, pl -mas also -ma·ta -mət-ə a mass resembling a tumor that represents anomalous development of tissue natural to a part or organ rather than a true tumor

ham·ar·toma·tous -'täm-ət-əs, -'tōm- adj

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n.

an overgrowth of mature tissue in which the elements show disordered arrangement and proportion in comparison to normal. The overgrowth is benign but malignancy may occur in any of the constituent tissue elements.

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ham·ar·to·ma (ham″ahr-toґmə) [hamart- + -oma] a benign tumorlike nodule composed of an overgrowth of mature cells and tissues that normally occur in the affected part, but with disorganization and often with one element predominating.