Acanthoma

Part of speech: noun

Definitions

1. A benign tumour arising from the epidermis, the outer layer of the skin, usually appearing as a small, firm growth
2. A non-cancerous growth formed in the outermost layer of skin, typically composed of cells from the prickle layer
3. An harmless epidermal tumour of the skin, often classed among the squamous tumours of dermatology and pathology

Etymology: Acanthoma is a medical coinage built from two Greek-derived pieces. The first, "acanth-", comes from Greek "akantha", meaning thorn or spine, and it also gave English the plant name "acanthus," whose spiny leaves inspired the decorative motif on Corinthian capitals. The second, "-oma," is the standard medical suffix for a tumour or growth, from Greek "-oma," which is used to name swellings and tumours of many kinds. The name fits the tissue it describes. An acanthoma is a benign growth made up of cells from the prickle-cell layer of the epidermis, the outer skin, and the cells of that layer are named for their spiny, bridged appearance under the microscope. So the word points to a thorn-like feature of the cells rather than to any spines on the skin itself.