Skin melanocytic tumor
Syndromes
Phacomatosis pigmentokeratotica
Author: Christopher S. Hale, M.D.
Topic Completed: 1 April 2013
Minor changes: 3 November 2020
Copyright: 2003-2021, PathologyOutlines.com, Inc.
PubMed Search: Phacomatosis pigmentokeratotica
Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Case reports | Clinical imagesCite this page: Hale CS. Phacomatosis pigmentokeratotica. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumormelanocyticphacomatosispigmento.html. Accessed January 17th, 2021.
Definition / general
- Rare syndrome defined by organoid nevus (occasionally with sebaceous differentiation) arranged along Blaschko’s lines plus speckled lentiginous nevus (SLN) of papular type (papular nevus spilus) in checkerboard pattern (Pediatr Dermatol 2011;28:715)
- Subdivided based on presence or absence of extracutaneous abnormalities including:
- Skeletal: bone cysts, kyphosis and scoliosis, foot and hand deformities, craniofacial defects, dislocation of hip hemihypertrophy and vitamin D resistant rickets
- Neurologic: hemimegalencephaly with contralateral motor disease, mental and cognitive deficiency, seizure, hydrocephalus, Dandy-Walker malformation, dysplasia of brain vessels, agenesis of corpus callosum, cerebral heterotropia, cortical agyria, microgyria or pachygyria
- Ocular: coloboma, epibulbar lipodermoid, nystagmus, corneal opacity, defects of optic nerve and cortical blindness
- Genitourinary and renal: rhabdomyosarcoma of bladder, nephroblastoma (Acta Derm Venereol 2010;90:279)
- Other: rhabdomyosarcoma of abdominal wall (J Am Acad Dermatol 2006;55:S16)
Terminology
- Also known as PPK
- Do not confuse with Phakomatosis pigmentovascularis, combination of melanocytic nevi and nevus flammeus
- Schimmelpenning syndrome: epidermal nevus associated with neurologic abnormalities, may apply to some cases of PPK
Epidemiology
- ~ 30 cases reported, no reported gender or ethnic predilection
- May be caused by twin-spot phenomenon
- 2 different mutant patches involving 2 adjacent or corresponding areas of the body, a form of mosaicism (Arch Dermatol 1998;134:333, Am J Med Genet 1999;85:355)
Sites
- May occur at any anatomic site
- Organoid nevus and speckled lentiginous nevus are usually (80%) ipsilateral
Case reports
- 6 month old boy with hemihypertrophy and rhabdomyosarcoma of abdominal wall (J Am Acad Dermatol 2006;55:S16)
- 10 year old girl with melanocytic-epidermal twin nevus syndrome and no extracutaneous involvement (Dermatology 1997;194:77)
- Malignant degeneration of both nevus components (Pediatr Dermatol 2005;22:44)
Clinical images
Images hosted on other servers:
Speckled lentiginous
nevus showing a
checkerboard
distribution
Speckled lentiginous nevus
Linear arrangement
of organoid
nevus on neck
and upper back
Systematized epidermal nevus of left side of body
Epidermal nevus
and pigmented
lesions right
forearm and back
Speckled lentiginous nevus in lumbar area
Epidermal nevus right side of trunk and leg
