GIANT CONGENITAL MELANOCYTIC NEVUS OF THE FACE : A CLINICAL CASE

Th is article describes a rare case of congenital anomalies involving giant melanocytic nevus of the face. Errors in the choice of treatment tactics for children with this disease and its complications can lead to poor esthetic and functional results. When selecting a method of plastic surgery to eliminate defects formed aft er removal of nevi, it is necessary to take into account anatomical features of the maxillofacial region. Our department has developed a complex scheme for treatment of these patients. Surgical treatment in combination with massage, myogymnastics, and regular medical observation have provided good esthetic results. An integrated treatment approach for children with giant nevi of the face allows early medico-social rehabilitation of children with this pathology.


Introduction
Congenital melanocytic nevi are benign melanocytic tumors usually discovered immediately aft er birth or appear during the fi rst weeks of life [1].Th e frequency of children born with giant nevi is approximately 1 in 20,000 newborns [2].
Allen and Spitz classifi ed nevi into the following types: epidermal, complex, intradermal, blue, and juvenile melanoma [3].Depending on the nevus structure, melanocytes are located in the epidermal layer of the skin and/or dermis [4].Baindurashvili et al. (2011) observed that congenital nevi are diff erent acquired nevi-they have larger size and increased cell count [5].Furthermore, according to the size, nevi are classifi ed as small, large, and giant.
The problems that doctors encounter in the treatment of giant nevi of face are considerable; there is no uniform nevi classifi cation and treatment protocols.Errors in the selection of treatment, and complications because of these errors, may result in poor esthetic and functional results.

Materials and methods
In April 2011, patient H., born in 2010, was seen for the fi rst time in the Department of Maxillofacial Surgery of Turner Scientifi c and Research Institute for Children's Orthopedics.The child was born with a giant nevus of the face.
Th e nevus had been increasing in size at the same rate as the growth of the maxillofacial region.Th e defect was spread over the buccal, periorbital, temporal, and left forehead areas, as well as over the glabella, dorsal and side planes of the nose, and left upper and lower eyelids.Th e lesion had a uniform dark brown color (Fig. 1 A, B) and was also covered with thick hair growth.There were no other melanocytic lesions on the child's body.
Aft er examination and consultations with the oncologist, the fi rst step of surgery was performedreconstructive and plastic surgery of congenital anomalies of the maxillofacial region, i.e., excision  of the nevus in the buccal area on the left side and closure of the defect with local tissues (rotation skin fl ap was used) (Fig. 2).
In 2012, the patient had a two-stage treatmentreconstructive and plastic surgeries.A tissue expander was inserted in the forehead, with total volume of fl uid being 120 ml (Fig. 3 A); nevus was excised on the left side of the forehead, and the defect was closed by the graft , harvested from the expanded skin area.Nevus area on the left lower eyelid was excised, and combined eyelid reconstruction was performed (full thickness skin graft from behind the ear was used) (Fig. 3 B-D).
In 2013, the patient had undergone the third stage of the surgery-reconstructive and plastic surgery.A tissue expander was installed in the left temporal region with full liquid volume being 50 ml.Th e frontotemporal area of the nevus was excised; then the area was closed with the fl ap from expanded skin.Nevus was excised from the nose area, and combined skin graft ing was performed (full thickness skin graft from behind the ear was used).
In 2014, the child had the fourth stage of surgery-reconstructive and plastic surgery: excision of the nevus portion on the upper eyelid, and combined skin grafting (full thickness skin graft from behind the ear was used).
Pediatric Traumatology, Orthopaedics and Reconstructive Surgery.Volume 3. Issue 2. 2015 To prevent formation of thick scars, aft er each stage of surgery, the patient received massage of the incision area and facial muscle exercises and was instructed to use scar gels.
He was under our observation for 1 year aft er the last surgery.Treatment results have remained stable.

Morphology
Based on a morphological study of surgical specimens, intradermal nevus was diagnosed given the abundance of small and medium-sized "nevus cells" (melanocytes), with a relatively small amount of weak oxyphilic cytoplasm, moderately basophilic nuclei, and predominantly irregular ovoid shape.
In the upper layers of the dermis (papillary layer), nevus cells that had formed were clearly demarcated, irregularly rounded nested clusters of different sizes (Fig. 6 A).In the reticular layer, cells formed extensive "fields" (Fig. 6 B).
In the deeper layers of the dermis, nevus cells spread to the boundary of the hypodermis and penetrated into this along fibrous septa, which separate the cells of subcutaneous fat tissue (Fig. 7).

Results and discussion
We strongly believe that surgical removal of the giant nevus of the face, confi rmed by histological examination (spread of melanocytes into deep tissues), is the treatment of choice.If one-step removal of nevus is impossible, multiple-step procedures should be used.We used the following methods to correct the defects formed after the removal of nevi: local skin graft s, free skin autograft s, and skin graft s harvested aft er tissue expansion.In the treatment of giant nevi of the face, all these techniques can be used in combination.
The choice of method of plastic surgery is specifi c for each patient, and depends on the size and location of the defect.One of the features of nevi of the maxillofacial region is that it is localized in close proximity to vital organs.If treatment strategy is improperly selected, severe scarring may form, resulting in ectropion, lip eversion, nasal atresia, microstomia, and/or limitation of mouth opening.Another feature is the defi cit of adjacent tissue, which limits the use of local tissue to close the defect.Furthermore, the use of skin for graft s from the surrounding areas (e.g., from behind the ear, submandibular region, or neck) is very limited, for a satisfactory esthetic result of similar color and thickness.Use of free skin graft s from distant parts of the body that are very diff erent from the face skin in texture, thickness and color, oft en leads to re-pigmentation and the need for repeat corrective operations.
While choosing a method of correction of the facial skin defect, it is necessary to take into account the anatomical features of the face.Diffi cult anatomical relief dictates the conditions: the face should be separated into zones and these zones restored consecutively, separating non-moving areas of the face from moving areas.
In our department, the protocol of treatment for children with this pathology is developed taking into account the features of the maxillofacial region.When a nevus is excised in the buccal region, the defect is closed with local tissues.We use large rotation fl aps derived from the lower zone of the face and neck.Th e skin in the area is best suited for esthetic performance.Tissue extension is a method of choice if a nevus is located on the forehead and scalp.In the treatment of giant nevi of the face, this technique gives good esthetic and functional results, which is especially important on exposed skin areas.This method allows for removal of large areas of giant nevi using excess skin harvested in the area adjoined to the nevus.Free skin autograft s are used in areas where it is impossible to use local or expansion tissues.Th is is particularly true for the area of the nose and orbit, where the donor site is behind the ear.Th e skin in this area is similar to facial skin in color and texture so that re-pigmentation was not observed.
Perhaps the most signifi cant role in getting good and lasting esthetic results is that of facial muscle massage and exercises.Long-term outpatient followup visits and active parental supervision is needed until the full formation of the maxillofacial region.Strict adherence to the principles of integrated treatment not only prevents the development of scar deformities but also significantly improves the quality of life of children with this defect.

Conclusion
In cases of giant nevi of the face, severe defi ciency of skin for graft s results in the need for a large number of surgical interventions.When treating children with giant nevi of the face, the best tactic is to use an integrated approach.It is necessary to combine different methods of plastic surgery to eliminate defects, while paying attention to the particular features of the maxillofacial area.Massage and facial muscles exercises play a key role in achieving good, lasting results of surgical treatment.Constant long-term monitoring and active participation of parents are necessary.Abiding by all of the principles of integrated treatment allows early medical and social rehabilitation of children with this defect.

Figure 1 .Figure 2 .Figure 3 .
Figure 1.A giant nevus of the face.A -front view, B -side view

Figure 4 .
Figure 4. Th e results a year aft er the third stage of treatment
Stepanova Yulia Vladimirovna -MD, PhD, chief of the department of maxillofacial surgery.Th e Turner Scientifi c and Research Institute for Children's Orthopedics.