Connective tissue nevi are benign, slightly elevated, well-circumscribed plaques that are often seen as an isolated skin finding, but can also be associated with systemic disease (Table 11-1).
TABLE 11-1Connective Tissue Nevi and Associated Syndromes ||Download (.pdf) TABLE 11-1 Connective Tissue Nevi and Associated Syndromes
|Syndrome ||Inheritance ||Cutaneous Findings ||Associated Features |
Familial cutaneous collagenomas
Autosomal dominant (possible LEMD3 gene mutation)
May have associated cardiomyopathy
Tuberous sclerosis collagenomas
Autosomal dominant (TSC1 or TSC2 gene mutation)
Shagreen patch, adenoma sebaceum, ash leaf macules, café au lait spots, periungual fibromas
Epilepsy, mental retardation, rhabdomyomas, calcified brain nodules
Autosomal dominant (LEMD3 gene mutation)
Dermatofibrosis lenticularis disseminata
Osteopoikilosis seen on x-ray, dysplasia of bone (leg bones, pelvis, hands, feet)
Mosaic mutation (AKT gene mutation)
Cerebriform connective tissue nevus, often on the feet (plantar collagenoma)
Areas of sporadic, progressive overgrowth, vascular malformations, linear epidermal nevi, dysregulated adipose tissue
SYNONYMS Nevus elasticus, juvenile elastoma, collagenoma, collagen hamartomas.
AGE Present at birth or childhood.
GENETICS May have an autosomal dominant inherited form; see Table 11-1.
Connective tissue nevi are localized malformations of dermal collagen and/or elastic fibers.
Connective tissue nevi appear in childhood or adolescence and are asymptomatic but can be disfiguring.
TYPE Slightly raised plaque (Fig. 11-1). May have a pebbly surface.
Connective tissue nevus
Flesh-colored, slightly raised plaque on the torso of an infant.
COLOR Flesh-colored to yellow.
SIZE Few millimeters to several centimeters.
NUMBER Solitary or multiple.
DISTRIBUTION Symmetrically over abdomen, back, buttocks, arms, thighs. Occasionally linear configuration.
Can be associated with systemic disease (Table 11-1).
Connective tissue nevi can be diagnosed clinically and confirmed by skin biopsy. They can be confused with other dermal or subcutaneous processes such as fibromatoses, fibrous hamartoma of infancy, infantile myofibromatosis, dermatofibromas, lipomas, scars, keloids, pseudoxanthoma elasticum, or mucopolysaccharidoses.
DERMATOPATHOLOGY Skin biopsy reveals disorganized collagen and/or elastin fibers in the dermis. Typically, there is an increase in collagen and a decrease or normal amount of elastin. Biopsies of the lesion can be easily mistaken for normal skin. Special staining for collagen or elastic fibers may aid in the diagnosis.