A variety of Benign Tumors can appear in children, such as: Dermoid Cysts, Fibrous Dysplasia and Skin Nevi.
Dermoid Cysts are small congenital tumors that contain skin cells, hair follicles, oil glands and smooth muscle cells. Often found behind the eyebrows, dermoids can occur anywhere on the skull and forehead. When they occur in the midline, an MRI or CT scan is necessary to determine if intracranial extension is present.
Endoscopic techniques can permit tumor removal through a smaller incision and resulting scar. Treatment is generally simple and sometimes may be carried out with endoscopic techniques. Intracranial extension is found in approximately 36% of midline dermoids. For these children a team composed of a pediatric craniofacial plastic surgeon and a pediatric neurosurgeon will provide assurance of a safe and cosmetic removal.
Fibrous Dysplasia is a benign congenital disease of unknown cause in which normal bone is replaced by fibrous tissue and immature bone. It may occur in a single bony site (monostotic) or in many bony sites (polyostotic). Because of its slow growth, the tumor is usually recognized in early childhood, and growth may stabilize in early adulthood or continue throughout life. In the skull the maxilla and frontal bones are the most commonly involved. Polyostotic involvement associated with cafe-au-lait skin spots and endocrine changes is called McCune-Albright syndrome.
Proliferation of the tumor can cause disfigurement and a variety of functional problems including:
- Obstruction of nasal passages
- Obstruction of sinuses
- Obstruction of tear ducts
- Displacement of the eye
A thorough evaluation by a pediatric dysmorphologist is necessary. Treatment of fibrous dysplasia is indicated for obstructive symptoms, visual disturbances, and disfigurement. The multidisciplinary craniofacial team at Children’s Hospital of San Diego is experienced with the surgical procedures used to treat craniofacial fibrous dysplasia.
Skin Nevi are common skin tumors caused by abnormal overgrowth of cells from the epidermal and dermal layers of the skin. Most nevi are benign, but some precancerous types must be monitored or removed. Types of nevi found in children include:
- Congenital Melanocytic Nevi
- Giant Congenital Melanocytic Nevi
- Blue Nevi
- Epidermal Nevi
- Sebaceous Nevi
- Spitz Nevi
The giant congenital nevus is greater than 10 cm in size, pigmented, and often hairy. Between 4% and 6% of these lesions will develop into a malignant melanoma. Since approximately 50% of the melanomas develop by age 2 years, and 80% by age 7 years, early removal is recommended.
Although removal of giant lesions can be quite challenging, the advances in surgical techniques and pediatric anaesthesia available in children’s hospitals has greatly improved the safety of treatment.
Congenital melanocytic nevi are found in about 1% of newborns. These small nevi are visible at birth, and are deeper and larger than nevi acquired later in life. Over 90% are less than 4 cm in size, and only 1% are large enough to be a giant congenital nevus. Unlike the giant form, the risk of malignancy in these small nevi appears to be greatest at or after puberty, thus allowing more time for consideration of treatment. A blue nevus is a blue-black nodule with a smooth surface that may be present at birth or may not appear until puberty. The deep pigmentation is due to large amounts of melanin pigment within the deeper dermis. The nevus of Ota and Ito are blue nevi with regional localization. Malignant degeneration is rare and these lesions are generally removed for cosmetic reasons. Epidermal nevi are linear, raised and at times “warty” lesions which may occur on the head.
When associated with other congenital disorders, the child may have epidermal nevus syndrome. The risk for malignant degeneration is unknown but uncommon. The sebaceous nevus is a congenital hamartoma (normal cells outside of their normal locations) of the sebaceous glands. By adolescence these lesions often thicken and run a risk of malignant degeneration, which is why removal is recommended. Spitz nevi are firm and pink and may be confused with a small vascular lesion. These lesions recur if not completely removed. It is unknown whether this lesion is a precursor to malignancy. Treatment for small lesions is simple excision and closure, sometimes performed by a pediatric dermatologist.
For larger lesions, movement of skin flaps or tissue expansion may be needed. The FACES+ pediatric craniofacial plastic surgeons are members of the vascular lesion team at Children’s Hospital of San Diego and provide assurance that complex excisions and reconstructions will yield an optimal cosmetic and functional outcome.