Dermatology Online Journal

Segmental neurofibromatosis of face
Anuja Agarwal¹, Devinder M Thappa², S Jayanthi², and KN Shivaswamy¹
Dermatology Online Journal 11 (3): 33

¹Department of Dermatology and STD, JIPMER, Pondicherry, India. dmthappa@jipmer.edu²Department of Pathology, JIPMER, Pondicherry - 605 006, India

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Abstract

A 38-year-old man presented with asymptomatic skin lesions over the left side of the face of 5-years duration. He had multiple discrete soft-to-firm papules and nodules on the left side of the face along the distribution of the mandibular division of the trigeminal nerve. Histopathology examination of one of the nodules (face) showed a non-encapsulated tumor of the dermis with normal overlying epidermis. The tumor consisted of loosely spaced spindle cells and wavy collagenous strands in a clear matrix. These features were consistent with our clinical diagnosis of segmental neurofibromatosis. This case is reported for its rarity and typical manifestations.

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Introduction

Segmental neurofibromatosis (SN) is a rare disorder, characterized by neurofibromas or café-au-lait macules limited to one region of the body [1]. Its occurrence on the face is even rarer; only few cases of SN over face have been described so far [2, 3, 4, 5, 6, 7, 8]. We report a case of SN on the left side of the face in the distribution of mandibular division of trigeminal nerve.

Clinical synopsis

Figure 1
Papules and nodules localized to the left side of the face along the distribution of the mandibular division of the trigeminal nerve

A 38-year-old man presented to our dermatology outpatient department with asymptomatic skin lesions over left side of the face of 5-years duration. These lesions began as pinhead sized and gradually grew in size to the present state. There was no history of seizures or other neurological disorders. None of the family members had similar disorder or neurological problem.

On cutaneous examination, multiple discrete soft to firm papules and nodules were localized to the left side of the face along the distribution of the mandibular division of the trigeminal nerve (Fig. 1). A few of the lesions were pedunculated and the buttonhole sign was positive. No other cutaneous abnormalities were detected. Hair, nails and mucous membranes were normal. Ophthalmological examination (including slit lamp for Lisch nodules and fundus examination) and central nervous system examination were normal. No signs of systemic neurofibromatosis or neurologic deficit were observed in this patient.

Histopathology examination of one of the nodules (face) showed a non-encapsulated tumor of the dermis with normal overlying epidermis (Fig. 2). The tumor consisted of loosely spaced spindle cells and wavy collagenous strands in a clear matrix (Fig. 3). These features were consistent with our clinical diagnosis of segmental neurofibromatosis.

Figure 2	Figure 3
Figure 2. Photomicrograph showing a non encapsulated tumor of the dermis with normal overlying epidermis (Hematoxylin & Eosin X 100)
Figure 3. Higher magnification photomicrograph showing a tumor mass made up of loosely spaced spindle cells and wavy collagenous strands in a clear matrix (Hematoxylin & Eosin X 400)

For aesthetic reasons, two nodules over the face were excised. Periodical medical surveillance was suggested to the patient.

Discussion

Segmental neurofibromatosis is a rare disorder, characterized by neurofibromas or café-au-lait macules limited to one region of the body. SN was first described by Gammel in 1931 [1]. Crowe et al. [2] proposed the term sectorial neurofibromatosis in patients with neurofibromas and café-au-lait macules in dermatomal distribution. Miller and Sparkes modified the nomenclature to segmental neurofibromatosis, the current term for neurofibromas of segmental distribution [3]. SN is included in type 5 of Riccardi's classification of neurofibromatosis [4]. SN was further subdivided in to in to four types by Roth et al. as true segmental, localized with deep involvement, hereditary segmental, and bilateral segmental. Our case belonged to the true segmental type [5].

To date approximately 150 cases of SN and only 5 cases of SN on the face have been reported [6, 7, 8, 9]. Commonly affected sites for SN are thorax and abdomen (55 %), upper extremities (20 %), and lower limb and face (10% each) [10]. Our patient is the sixth reported case of SN affecting the face.

SN is thought to arise from post-zygotic somatic mutation in the primitive neural crest cells. In this type of mutation, there is no systemic compromise and usually no family background. Early somatic mutations cause a generalized disease while late mutations cause a more localized disease [6, 7].

Segmental neurofibromatosis needs to be differentiated from epidermal nevus, nevus lipomatosus cutaneous superficialis, trichoepitheliomas, and syringocystadenoma papilliferum [7].

In contrast to NF-1 and NF-2, the systemic involvement in SN is uncommon. Nevertheless, a few cases have been reported with extracutaneous manifestations including visceral neurofibromas, soft tissue hypertrophy, skeletal abnormalities, unilateral renal agenesis, and adenocarcinoma of colon [8]. Association of SN with other manifestations necessitates a thorough examination of the affected individual.

To conclude, this case of SN is reported for its rarity and typical manifestations.

References

1. Gammel JA. Localized neurofibromatosis. Arch Dermatol Syphilol 1931; 24:712

2. Crowe FW, Schull WJ, Neel JV. A clinical, pathological and genetic study of multiple neurofibromatosis. Springfield IL.:Charles C Thomas, 1956:3-181.

3. Miller RM, Sparkes RS. Segmental neurofibromatosis. Arch Dermatol 1977; 113:837-8.

4. Riccardi VM. Neurofibromatosis: clinical heterogeneity. Curr Prob Cancer 1982; 7:1-34.

5. Roth RR, Martines R, James WD. Segmental neurofibromatosis. Arch Dermatol 1987:123:917-920.

6. Kumar S, Kumar RP. Multisegmental neurofibromatosis. Indian J Dermatol Venereol Leprol 2004; 70:361-363.

7. Dogra S, Kmaran MS, Radotra BD, Kanwar AJ. Segmental neurofibromatosis on the face. Clin Exp Dermatol 2004; 29:556-558.

8. Hager MC, Cohen PR, Tschen JA. Segmental neurofibromatosis: Case reports and review. J Am Acad Dermatol 1997; 37:864-869.

9. Dorina LC, Antonieta DG. Josefa NS, Arturo GC. Segmental neurofibromatosis of facial localization. Int J Dermatol 2005; 44; 583-586.

10. Koedijk FHJ. Segmental neurofibromatosis. Br J Dermatol 1987; 117:790-791.

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