The hyaline material may also be present in the muscles and bones. Skin lesions are present at birth or developin early childhood. There may be small pearly papules or nodules, particulary on the face or neck. These may be hard or soft, fixed or mobile, and they may ulcerate. Gingival hypertrophy is commonly present, and flexion contractures of the fingers,elbows, hips and knees may develop.
Osteolytic lesions can occur in the skull, long bones or phalanges.
The musculature is poorly developed. The condition persists into adult life and the joint contractures are disabling. This is unsatisfactory. The tumours do not respond to radiotherapy, and they may recur after excicion. Joint contractures may respond to intralesional steroid injections in the early stages and they may also respond to systemic steroid and physiotherapy.