Koenens tumor (KT), also commonly termed periungual angiofibroma,: 668  is a subtype of the angiofibromas. Angiofibromas are benign papule, nodule, and/or tumor lesions that are separated into various subtypes based primarily on the characteristic locations of their lesions. KTs are angiofibromas that develop in and under the toenails and/or fingernails. KTs were once considered as the same as another subtype of the angiofibromas viz., acral angiofibromas. While the literature may still sometimes regard KTs as acral angiofibromas, acral angiofibromas are characteristically located in areas close to but not in the toenails and fingernails as well as in the soles of the feet and palms of the hands. KTs are here regarded as distinct from acral angiofibromas. KTs most commonly develop in individuals who have the rare genetic disease, tuberous sclerosis (a heritable neurocutaneous disorder) and uncommonly in individuals that do not have this genetic disease. One individual with another rare genetic disease that has similarities to tuberous sclerosis, the Birt-Hogg-Dube syndrome, has also been reported to have typical KT findings.KTs are strictly benign (i.e. do not metastasize) but may be painful, disfiguring, and sometimes large and/or incapacitating lesions. They have often been treated by strictly local surgical resections. However, they do have a high rate of recurrence at the site of resection and therefore have been treated with various other non-invasive local measures in efforts to avoid recurrences; these other methods have also been preferred to treat numerous tumors in individuals, for cosmetic reasons, and/or to relieve tumor-induce incapacitations.
excision of the tumor’s protruding portion followed by treatment of the proximal perionych [i.e., skin around a nail] with phenol to eradicate the root of the tumor); and in individuals with tuberous sclerosis, topical application of sirolimus, i.e. rapamycin, (1% solution). Some of the latter methods have been used in order to preserve the nail matrix and nailplate and may be ideal for younger patients with few tumors since they may leave a normal appearing nail. See also
List of cutaneous conditions
Nail anatomy


== References ==