Giant keratoakanthoma D23.-

Rare variant of keratoacanthoma characterized by continued, continuous growth in contrast to classic keratoacanthoma, which usually presents as growth-limited. Giant keratoacanthoma initially presents as a typical, fast-growing keratoacanthoma, but does not behave in a growth-limited manner, but continues to grow peripherally and can thus reach a size of up to 10 cm.

A special variant of giant keratoacanthoma is keratoacanthoma centrifugum marginatum, which is characterized by uninhibited peripherally migrating growth. In this growth formation, the typical clinical (recognition) pattern of classic keratoacanthoma is lost.

Back of the hand, nose, forearms; but more rarely also on non-exposed skin areas.

The giant keratoakanthoma shows the classical clinical morphology with peripheral lip formation and central horn plug, as well as the characteristic eruptive, "unexpectedly fast" growth behaviour (rapid growth within a few weeks and months) of the classical keratoakanthoma.

In giant keratoakanthoma the differentiation from a common squamous cell carcinoma is difficult both clinically and histologically. The diagnosis is corroborated by the growth behaviour, by the characteristic clinical morphology (lateral lip formation, central corneal clot) and by histological confirmation

1. Xiao H et al (2021) Keratoacanthoma centrifugum marginatum. Dermatol Online J 27:13030/qt5vp5f7bq.