EPOS

European Paediatric Ophthalmological Society

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Unifocal Langerhans' Cell Histiocytosis

Trancoso Vaz Fernando, Cabral Jo, Bernardo Manuela, Rodrigues Jo, Costa e Silva Filomena, Esperancinha F.E.
¹Fernando Fonseca Hospital - Amadora/Sintra - Portugal

Purpose: To report a case of unifocal Langerhans' cell histiocytosis localized to the superolateral wall of the orbit. A brief review of the main clinicopathologic and CT imaging features is made. Methods:Case report. A 4-year-old girl was initially examined with a 4-week history of slowly progressive blepharoptosis and periorbital swelling of the right eye. Results:Computed tomographic scan showed a mass in the right orbit eroding into the right frontal bone; exploratory orbitotomy with biopsy revealed the presence of histiocytic cells with eosinophilic cytoplasm and convoluted nuclei, S100 immunoreactivity, and tennis-racket-shaped Birbeck granules (electronic microscopy)confirming the diagnosis of Langerhans' cell histiocytosis. Systemic evaluation for other possible tumor localization was negative. The patient was treated with oral prednisone. Four months after initial examination the monostotic Langerhans'cell histiocytosis had completly resolved. Conclusion:Langerhans'cell histiocytosis is not a well defined or predictable disease. Instead,it is a spectrum of disorders of unknown etiology that vary widely in presentation and natural history, but have in commom the proliferation of histiocytic cels and infiltration of these cells into normal tissues. Lesions may developed in any tissue, but bone, skin and lymph nodes are the most commonly affected. The orbital bones are an occasional site of involvement, most commonly involving the orbital frontal bone. The disease can be unifocal (eosinophilic granuloma), multifocal (Hand-Shuller-Christian disease) or systemic (Letterer-Siwe disease). Unifocal Langerhans' cell histiocytosis is a rare, benign, proliferative disorder with a median age of diagnosis - 1 to 4 years old. Despite progress in clinical treatment, the aetiology and pathogenesis of this disease remain unknown. Treatment may include surgery, corticosteroids or low-dose radiotherapy. There are also some reports of spontaneous regression. Bibliography: 1. Shields J, Shields C 'Langerhans' cell histiocytosis (eosinophilic granuloma)' in Atlas of orbit tumors ed Lippincott Williams & Wilkins p. 156-9 (1999) 2. Huang F, Arceci R 'The histiocytosis of infancy' Semin Perinatol 23(4): 319-331 (August 1999). 3. Schmitz L, Favara BE 'Nosology and pathology of Langerhans' cell histiocytosis' Hematol Oncol Clin North Am 12(2): 221-246 (1998) 4.McLean I, Burnier M, Zimmerman L, Jakobiec F 'Unifocal and multifocal eosinophilic granuloma (Langerhans' cell histiocytosis)' in Atlas of tumor pathology ed Armed Forces Institute of Pathology p. 284-285 (1994) 5. Hidayat AA et al 'Langerhans' cell histiocytosis and juvenil xanthogranuloma of the orbit - clinicopathologic, CTand MR imaging features' Radiol Clin North Am 36(6): 1229-1240 xii-1998