Abstract
Divided nevus, which is also known as “kissing nevus,” “split ocular nevus” and “panda nevus” is a rare congenital dermatological abnormality that occurs on opposing margins of upper and lower eyelids. There is a paucity of literature on this rare anomaly, with most knowledge from this disease process derived from isolated case reports and series. The purpose of this study is to report a new case of divided nevus of the eyelid and to discuss the unique embryology, pathology, and potential treatment options for this rare entity. A systematic review of literature was performed of the English literature on PubMed and Medline with just under 150 cases reported in the literature. The vast majority of the divided nevi seen in this review were medium sized and of the melanocytic intradermal type. There were no described cases of malignant transformation in any of the documented cases. Numerous methods for reconstruction were described including the entire reconstructive ladder with both one and two staged approaches. In this review, we present basic guidelines to the reconstruction of these complicated defects, although ultimate treatment should be individualized and dependent on surgeon comfort.
1
Case discussion
An eight year old male presented to our clinic with a congenital pigmented lesion that had been growing commensurate with the patient’s age. The patient’s mother sought advice regarding the management of this from the dermatologist whose clinical diagnosis was that of congenital nevocellular nevus ( Fig. 1 ). The patient had begun to be teased at school and it was felt that excision was the best treatment for the patient considering both the potential for malignant transformation and the psychological well-being of the child. A treatment plan was developed that included excision and a local advancement flap with a V to Y closure of the defect lateral to the lateral canthus and a full thickness skin graft for the eyelid reconstruction. We elected to leave a very small rim of nevus at the lash line so as not to permanently remove the eyelashes, as we felt the risk of recurrence would be quite low. The patient had no complications and follow up was one year. The final pathology was a congenital nevocellular nevus.
2
Introduction
Divided nevus, which is also known as “kissing nevus, ” “split ocular nevus” and “panda nevus” is a rare congenital dermatological abnormality that occurs on opposing margins of upper and lower eyelids. It was first described in 1919 in the German literature by Fuchs and is a rare and interesting embryological phenomenon . Most knowledge of this unique disease process has been centered on random case reports and series. Although there is a relative paucity of literature on this anomaly, it probably occurs much more frequently than currently recognized.
A similar interesting process of congenital divided nevus has also been described elsewhere in the body including the penis and between fingers, however this is much less common than the eyelid . Treatment, if at all, has included non-surgical and surgical management and still remains quite controversial with numerous methods reported in the literature.
The purpose of this study is to retrospectively review the current English literature and (1) review the anatomy and embryologic development of congenital divided nevus, (2) review the basic pathology with such lesions and their potential for malignant transformation, and (3) propose a preliminary treatment algorithm with a focus on reconstructive management.
2
Introduction
Divided nevus, which is also known as “kissing nevus, ” “split ocular nevus” and “panda nevus” is a rare congenital dermatological abnormality that occurs on opposing margins of upper and lower eyelids. It was first described in 1919 in the German literature by Fuchs and is a rare and interesting embryological phenomenon . Most knowledge of this unique disease process has been centered on random case reports and series. Although there is a relative paucity of literature on this anomaly, it probably occurs much more frequently than currently recognized.
A similar interesting process of congenital divided nevus has also been described elsewhere in the body including the penis and between fingers, however this is much less common than the eyelid . Treatment, if at all, has included non-surgical and surgical management and still remains quite controversial with numerous methods reported in the literature.
The purpose of this study is to retrospectively review the current English literature and (1) review the anatomy and embryologic development of congenital divided nevus, (2) review the basic pathology with such lesions and their potential for malignant transformation, and (3) propose a preliminary treatment algorithm with a focus on reconstructive management.
3
Literature review
We performed a Medline and PubMed search of the entire English literature for all cases of divided nevus of the eyelid and found 149 cases reported in 23 papers ( Table 1 ). Search terms included, “divided nevus, spitting nevus, panda nevus.” Non-English literature was excluded from this review.
| Author | Journal, year | Number patients | Treatment and/or reconstruction technique | Histologic type | Follow-up period, complications |
|---|---|---|---|---|---|
| Jia et al. . | Ann Plast Surg, 2012 | 73 | 1-stage or 2-stage advanced skin flap (18), musculocutaneous flap, skin graft, tarsoconjunctival flap (1), conjunctiva flap or oral mucosal graft (5), primary silicone tube implantation (13) | Intradermal (40), junctional (15), compound (18) | 4–121 months (mean 2.5 years); asymmetry of palpebral fissure (6), partial cilia loss (7), redundancy of skin graft (2) |
| Ghosh et al. . | Orbit, 2010 | 1 | Primary closure, secondary intention, skin graft (1) | Intradermal melanocytic (1) | 3 months, partial cilia loss |
| Zhu et al. . | Ophthal Plast Reconstr Surg, 2009 | 10 | Orbicularis oculi musculocutaneous flap (10), postauricular SMAS-pedicled flaps (3), reversal STA-flaps (3) | Melanocytic (9), melanocytic w/ cellular element (1) | 6 to 36 months; one SMAS-pedicle flap showed partial epidermal necrosis and excess bulk |
| Ashfaq et al. . | J Plast, Reconstruct & Aesth Surg, 2009 | 1 | Primary closure, secondary intention, skin graft (1) | Melanocytic (1) | 7 months |
| Alfano et al. . | In vivo, 2007 | 3 | Tarso-conjunctival flaps w/ skin grafts (1), autologous cultivated conjunctival epithelium (1) | Dermal nevocellular nevus w/ junctional residuals (1) | 6 years |
| Yildirim et al. . | Int Opthalmol, 2007 | 1 | Musculocutaneous flap w/ tarsoconjunctival flap (1) | NR | 6 months; no complications |
| Cologlu et al. . | PRS, 2007 | 1 | Axial bilobed tulip flap (STA island) | NR | 10 months, excess bulk upper eyelid |
| Papadopoulos et al. . | J Plast Reconstr & Aesth Surg, 2005 | 7 | Musculocutaneous flap, FTSG | Cellular (3), melanocytic (1) | No follow-up; Partial or complete cilia loss (2) |
| Wu-Chen et al. . | Br J Opthal, 2004 | 1 | 2- stage incomplete excision w/ STSG followed re-excision w/ FTSG | Intradermal (1) | 29 years |
| Yap et al. . | Br J Plastic Surg, 2001 | 4 | FTSG (4) | Compound (3), Intradermal (1) | Epiphora (1), ectropion (1) |
| Ribuffo et al. . | Ophthal Plast Reconstr Surg, 1996 | 1 | Lateral canthotomy and tarsoconjunctival flap w/ FTSG | Intradermal nevocellular nevus with junctional residuals | 7 months, no complications |
| Westfall et al. . | Opthal Surg, 1991 | 1 | Observation | Compound | NR |
| Papadopoulos et al. . | PRS, 1991 | 1 | 2-stage, FTSG (1), musculocutaneous flap (1) | Compound (1) | No follow-up, Cila loss |
| Kasai et al. . | Ophthal Plast Reconstr Surg, 1990 | 1 | Modified Kuhnt–Szymanowski procedure | NR | 11 months, no complications |
| McDonnell et al. . | Br J Opthal, 1988 | 1 | Failed dermabrasion, FTSG (1) | Melanocytic w/ junctional activity | Recurrence after dermabrasion (1) |
| Betharia et al. . | Indian J Opthal, 1988 | 2 | Canthotomy and cantholysis with primary closure (1); Tenzel’s semicircular flap (1) | NR | NR |
| De Pietro et al. . | Cutis, 1981 | 2 | Observation | Nevocellular and nevoid depigmented lesion | NR |
| Ehlers et al. . | Acta Ophthalmol, 1969 | 10 | Cryotherapy (2), FTSG (2), simple excision with primary closure(2), observation (4) | Intradermal nevus (3), nevus with junctional activity(2) | NR follow-up, Ectropion after serial excision with FTSG |
| Ehlers et al. . | Arch Opthamol, 1965 | 1 | NR | Intradermal (1) | NR |
| Hung-Yin et al. . | Acta Chir Plast, 1960 | 14 | Tarsoconjunctival flap (14), STSG (14) (2 or 3- stage) | Intradermal (5), Junctional (1) | 7 years |
| Harrison et al. . | Arch Dermatol, 1960 | 1 | Observation | Compound (1) | 3 months |
| Lo et al. . | Chin Med J, 1951 | 3 | Observation | NR | NR |
| Fuchs et al. . | Urol Cutaneous Rev, 1950 | 9 | Observation, excision w/ reconstruction (1 — details NR) | NR | NR |
3.1
Anatomy and embryology
The upper and lower eyelids are composed of four main layers including a very thin cutaneous layer, a muscular layer, tarsal layer, and palpebral conjunctiva. The skin layer is extremely thin (< 1 mm) and composed of a keratinized, stratified squamous epithelium with underlying dermis composed of multiple elastic fibers. The muscle layer is mainly composed of the palpebral portion of the orbicularis oculi, with levator palpebrae superioris attaching to the lower one-third of the tarsus and skin in the upper eyelid. Muller muscle arises from levator and inserts on the superior portion of the tarsus, however it is also only present on the upper lids. The capsulopalpebral fascia is analogous to Muller muscle, however it is much less developed and presents only in the lower lid. The tarsal layer is mainly composed of dense connective tissue containing Meibomian or sebaceous glands. The remaining layer is the palpebral conjunctiva, which lines the inner surface of the lids and continuous with the bulbar conjunctiva.
Embryologic studies of the human eye have shown that the palpebral buds (preliminary eyelids) develop during the 7th week of gestation (21 mm crown-rump length) above and below the cornea. By the 9th to 10th gestational week (38–40 mm) the two eyelids meet and the epidermal layer fuses, without any connecting mesenchymal layer. During the 20th week, the eyelids begin to separate, after lipids start to appear at the junctional zone, with complete separation occurring at 28 to 30 weeks (180 to 200 mm) .
It is believed that somewhere between the critical period of the 12th and 14th week of gestation normal and abnormal melanocyte migration from melanoblasts originating from the neural crest migrates to the undersurface of the embryonic epidermis of the scalp and face . Because of their neural crest origin, melanoblasts can show localized proliferations in the junctional, intradermal, and compound nevi .
3.2
Pathology and staging
Congenital nevi roughly occur in 1% of newborns, and yet surprisingly less than 150 cases of divided congenital nevi have been reported in the literature . Historically, two classification systems have been used to describe congenital nevi based either on total size of nevus or on histology ( Table 2 ). In the former, the classification is based on the diameter (in cm) of the nevus: a) small (< 1.5 cm), b) medium (1.5–19.9 cm), c) large (> 20 cm). The vast majority of congenital nevi are of the small type. The majority of the divided nevi reported in this literature search found the lesions to fit into the medium type.
