Tumors of the Head and Neck
Many lesions can occur in the head, neck, or face which require treatment by craniofacial techniques. The initial appearance of a lesion may be a swelling or a lump. It could appear on the skin of a newborn infant or on an older patient which in either case needs to be investigated and differentiated from any number of lesions. Most of these occur in children but may continue into adulthood. They are primarily related to embryologic and/or abnormalities of cellular growth, which are present in the child at the time of birth, or appear during early childhood development.
Fibrous dysplasia represents a benign bony tumor which can occur in any portion of the craniofacial skeleton. Rarely, if ever, does this turn into a malignant tumor or a sarcomatous lesion. They usually develop in early childhood or teenage years and are very slow growing and progressive. They may appear as a bump on the forehead, face or skull which gradually increases in size. It may also occur around the orbit with displacement of the eye and orbital area which may result in visual disturbances. It may also occur anywhere in the bones of the face with gradual occlusion of the surrounding structures and end up presenting with a mass or lump in that bone or region. This involvement of the bones of the skull base or facial skeleton can present with nerve impingement presenting with changes in vision, sense of smell, or facial animation.
The cause of fibrous dysplasia is not known. It is due to the overgrowth of fibrous cellular components which give rise to this slow growing tumor. Most frequently they are seen in children. It may occur in a single bony site (monostotic) or in many bony sites (polyostotic). 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
Expectations & Treatment
Treatment of fibrous dysplasia is indicated for obstructive symptoms, visual disturbances, and disfigurement. Evaluation is both clinical and radiographic. A CT scan examination is generally diagnostic and serves to define the entire scope of the lesion. A complete ophthalmological exam may be required pre-operatively.
Treatment consists of surgical extirpation of the involved skeletal bone with reconstruction using techniques such as split cranial bone grafting. In some special cases, the optic nerve may need to be decompressed so as to minimize any risk to these structures. The prognosis is good with complete resection, or near total removal, usually being accomplished and an excellent aesthetic result expected with minimal disability or deformity.
Dermoid cysts are thought to be embryological remnants which form during the development of a child in utero. These cysts are small congenital tumors that contain skin cells, hair follicles, oil glands and smooth muscle cells. They may arise from the foramen cecum as small outpouchings of the dura, or they may only be superficial. The lesion may occur anywhere along the mid-axial line of the face but are most commonly noted at the bridge of the nose, or lateral portion of the eyebrow.
Expectations & Treatment
Lateral dermoids tend to be of superficial origin and diagnosis is generally limited to a thorough clinical exam. Treatment is surgical and consists of cyst removal with mobilization and advancement of the surrounding tissues in order to close the cavity created by the cyst. Frequently, a dermoid will cause a small bony defect and this too will be masked by a well designed plastic surgical closure.
Medial or midline dermoids require a slightly more involved diagnostic work-up. In this setting, there is a high rate of communication between the dermoid and the underlying dura through the foramen cecum. Due to this possibility, a CT scan is required prior to any surgical intervention. If there is communication with the underlying dura, the aid of our pediatric neurosurgeon is required to remove the lesion. If the lesion does not communicate with the dura, a limited surgical approach is all that is needed.
Facial dermoids are benign lesions and as such, treatment plans tend to be highly successful. Surgical intervention usually provides a complete resolution of all symptoms and recurrence is rare.
Neurofibromatosis is well known and was first felt to be occurring in James Merrick, or the “elephant man”. The cause of neurofibromatosis, or von Recklinghausen disease, is unknown but there is a genetic predisposition.
The characteristics present in an infant with simple cafe au lait spots and minimal deformity. In time, this may progress into more massive deformities. Three basic types exist. Plexiform neurofibromatosis are flat lesions of moderate size which tend to follow the nerve or nerve axis with marked enlargement. This type often infiltrates through the skin, subcutaneous tissue, deep planes, and can even cause distortion of growth of the bone.
Mollusca fibrosa are small round nodules which may be present in large numbers. Elephantiasis neurofibromatosis is the most impressive manifestation due to its size. In this setting the lesion will lead to massive overgrowth of both the skin and the associated soft tissue.
Expectations & Treatment
Frequent, repeated surgical excision is performed and can give improvement. But since infiltration is throughout all of the planes of the tissues involved, it can be a long term progressive problem.
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.
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% is 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. For larger lesions serial excisions, skin flaps, grafts, or tissue expansion may be needed.