This lesion is characterized by a circumscribed and raised area in which the polyps and their associated skeleton are enlarged in relation to those of the surrounding tissue. This lesion has been termed "gigantism", corallite distortion, "hyperplasm" and other malformations. Patterns of ridges and valleys in brain corals, or circular polyps in star corals are enlarged and project above surrounding corallites. The cells typically have normal cellular structures, but only one type in one species has been studied.

Area of accelerated growth on boulder brain coral (C. natans)