Schwannoma of the left superior eyelid in a 10-year-old child Schwannoma em pálpebra superior esquerda em criança de 10 anos

1 Resident in Ophthalmology, Recife Eye Institute, Recife/PE, Brazil; 2 Trainee at the Cornea and Refractive Surgery Unit, Santa Casa de Misericórdia, Belo Horizonte/MG, Brazil; 3 Adjunct Professor of Pathology, University of Pernambuco (UPE), Recife/PE, Brazil; 4 Adjunct Professor of Ophthalmology, Federal University of Paraíba (UFPB), João Pessoa/PB, Brazil; Federal University of Campina Grande (UFCG), Campina Grande/PB, Brazil.


CASE REPORT
Ten-year-old female patient complaining of a lump in the lateral corner of the upper left eyelid; the patient was diagnosed with chalazion and underwent surgical excision.During surgery it was noted that the lesion's appearance was not compatible with the medical diagnosis of chalazion, but suggestive of a hard, well-demarcated tumour of the subcutaneous tissue with benign features.The lesion was excised and submitted to histopathology.Macroscopic examination showed an irregular fragment of whitish, compact, elastic tissue measuring 1.1 x 0.7 x 0.2 cm.Microscopic examination showed histological sections consisting of spindle-shaped cells with oval nuclei and elongated oval cytoplasm forming bundles, most of them loose, corresponding to the Antoni A pattern for schwannoma, as well as small areas corresponding to the Antoni B pattern (Figure 1A).The lesion was diagnosed as a schwannoma (neurilemmoma) with a histopathological predominance of the Antoni A pattern.
Immunohistochemical examination of the lesion showed that the tissue was immunopositive for the S-100 protein and immunonegative for the other tested proteins (melan-A, smooth muscle actin, GEAP [glial fibrillary acidic protein], and the Ki-67 antigen), with evidence of low cell proliferation (Figure 1B).These tests confirmed the diagnosis of schwannoma.
The patient recovered well postoperatively with complete wound healing.After six months there were no signs of relapse.The patient is still undergoing follow-up.
Schwannomas can be associated with neurofibromatosis, but when isolated they are not related to this condition (2,5) .
Schwannomas occur in two histological patterns.The Antoni A pattern, found in the patient presented here, presents with spindle-shaped cells arranged in compact stacks, usually in palisades.The Antoni B pattern is characterised by cells dispersed in a myxoid matrix (3,5,6) .
Eyelid schwannomas are extremely rare and usually occur in adults (2)(3)(4)(5)(6)(7)9,10) . Only wo other cases have been reported in children (1,8) .The patient presented here was 10 years old at the time of diagnosis. Amongthe cases reported in the literature, the incidence in males and females seems to be similar (there are reports of schwannoma in 6 males 8 females, including the case presented here) (Table 1).
The diagnosis of eyelid schwannoma can be suggested by clinical examination and imaging studies in conjunction with its macroscopic appearance during surgery; however, because the condition is so rare, it is seldom considered in the differential diagnosis of eyelid masses and the diagnosis is often made by

Figure 1 :
Figure 1: A) Histological sections showing a proliferation of spindleshaped cells with oval nuclei and elongated oval cytoplasm forming bundles, most of them loose, corresponding to the Antoni A pattern for schwannoma, as well as small areas corresponding to the Antoni B pattern.B) The tissue was immunopositive for the S-100 protein.