Isolated Langerhans Cell Histiocytosis of the T12 Vertebra in an Adolescent

Abstract not available. Introduction provided instead.

Langerhans cell histiocytosis (LCH) represents a group of rare, benign, histologically similar disorders of relatively unknown etiology and pathogenesis.¹ Research suggests that the etiology is multifactorial, possibly involving the patient’s environment, infection (human herpes virus 6), immune response, and/or genetics.² While some controversy exists over which disease subtypes should be classified within this grouping, disorders such as solitary eosinophilic granuloma, Hand-Schüller-Christian disease, and Letterer-Siwe disease are typically included,³ representing unifocal, multifocal, and disseminated variants, respectively.² Although it was once believed that these 3 diseases were separate entities, it is now recognized that they are different manifestations of the same disease process, involving a clonal proliferation of Langerhans cells.⁴

LCH is a disease of childhood, with a peak incidence between 5 and 10 years of age,⁵ although recent studies have shown a shift in the trend toward even younger children, predominantly aged 1 to 4 years.2 Nearly 85% to 90% of cases of LCH primarily affect bone, although other organ involvement has been reported.5 Despite LCH’s high percentage of bone involvement, the incidence of vertebral involvement ranges from only 7.8% to 25%.⁶ As the incidence of LCH is approximately 5.4 million children per year,² or 1:2,000,000 per year,⁶ the number of cases involving the vertebra is likely less than 1 million per year.

We report the case and follow-up of a 15-year-old boy with isolated LCH of the T12 vertebrae.