Connective Tissue Nevus Clinical Presentation

Collagenomas have been associated with multiple medical syndromes. For example, 72% of patients seen at the National Institutes of Health (NIH) for evaluation of multiple endocrine neoplasia (MEN) type 1 over a 3-year period were noted to have these lesions.^[3] Shagreen patches of tuberous sclerosis are collagenomas, and collagenomas have also been associated with Down syndrome. Other diseases associated with collagenomas include chronic myelocytic leukemia, syphilis, Cowden disease,^[4] Proteus syndrome,^[5] and encephalocraniocutaneous lipomatosis.

• Familial cutaneous collagenoma: Familial cutaneous collagenoma (FCC) is an inherited disorder. Lesions typically occur in the postpubertal period. Increased numbers of lesions during pregnancy have been reported in a few patients.^[6] Cardiac disease has been associated with FCC.
• Shagreen patch: Shagreen patch is a collagenoma variant associated with tuberous sclerosis, a disease most commonly inherited in an autosomal dominant pattern. The genetic defects are in the TSC1 and TSC2 genes, which produce hamartin and tuberin, respectively. Flesh-colored plaques of variable size are primarily located in the lumbosacral area. They can occur singularly or asymmetrically in limited numbers.
• Eruptive collagenoma: This is one of the acquired variants of collagenoma characterized by nodules similar to those of FCC.
• Isolated collagenoma: This is characterized by nonfamilial hamartomas of the collagen type.
• Plantar cerebriform collagenoma: This is a disorder that can be inherited or develop sporadically. It is one of the most characteristic findings in persons with Proteus syndrome, in whom it appears in the first or second year of life.
• Buschke-Ollendorf syndrome: Buschke-Ollendorf syndrome is a genodermatosis characterized by abnormalities of the skin and the bone. It is inherited in an autosomal dominant fashion. Skin lesions, referred to as dermatofibrosis lenticularis disseminata, typically arise before puberty and can be present at birth. Bone lesions of osteopoikilosis are asymptomatic and of no pathologic significance.
• Nevus anelasticans: This condition is not inherited. Elastomas can occur during childhood or in early adolescence.
• Juvenile elastoma: These develop in a sporadic fashion.
• Nevus elasticus: This is an elastoma that is an acquired condition.
• Nevus mucinosis (Hunter syndrome)^[7] : These lesions appear before age 10 years and can disappear spontaneously. Hunter syndrome is a lysosomal storage disorder usually inherited in an X-linked recessive pattern; however, a less frequent autosomal recessive pattern has been noted. The etiology of Hunter syndrome is the lack of iduronate sulfatase, leading to the accumulation of the mucopolysaccharides dermatan sulfate and heparan sulfate.

Patients should receive a complete physical examination to rule out any associated conditions.

• FCC: Multiple, indurated cutaneous papulonodules that vary in size are located over the upper two thirds of the back (see the image below). Familial cutaneous collagenoma.
• Shagreen patch: Flesh-colored plaques of variable size are located singularly or asymmetrically in limited numbers in the lumbosacral area. Note the image below. Shagreen patch.
• Eruptive collagenoma: Multiple cutaneous papulonodules are located on the extremities, the lower part of the trunk, and the ears.
• Isolated collagenoma: This condition is characterized by cutaneous papulonodules, sometimes in a zosteriform pattern. Note the image below. Collagenoma
• Plantar cerebriform collagenoma: This condition is characterized by cerebriform plaques on the palms and the soles.
• Buschke-Ollendorf elastomas: Lesions consist of minimally elevated and firm nodules that may be grouped together in one or several plaques, or they may be widely disseminated. They vary in size from 0.5-8 cm in diameter, and they may have a wrinkled, pigskin appearance. The most common areas of involvement include the abdomen, the back, the buttocks, the arms, and the thighs. Nevi are asymmetric and occur on the lower part of the trunk and the extremities.
• Nevus anelasticans: These small, yellowish, perifollicular papules lack elastic fibers. They are located on the chest.
• Juvenile elastoma: Numerous nodules are present on the lower part of the trunk and the anterior aspects of the thighs.
• Nevus elasticus: Lesions are similar to those of juvenile elastoma.
• Nevus mucinosis (Hunter syndrome): Symmetric, small, firm papules that are located on the arms, on the chest, and over the scapular region give the skin a pebbled appearance. Hunter syndrome involves multiple organ systems, including severe CNS impairment (eg, mental retardation, deafness, progressive neurologic disease), coronary heart disease, hepatosplenomegaly, and respiratory disease. It is also associated with coarse facial features.

The cause of connective tissue nevi is unknown.