Langerhans cell histiocytosis: Current concepts in dentistry and case report

Langerhans cell histiocytosis in a pediatric patient: A typical presentation with oral manifestations

Langerhans cell histiocytosis (LCH) is a rare hematological disorder characterized by abnormal proliferation of Langerhans cells. Head and neck region is commonly involved with oral manifestations appearing first in many instances. A thorough knowledge of the disorder and an interdisciplinary approach warrant for the better outcome of the condition.

Langerhans cell histiocytosis: A diagnostic enigma in the oral cavity

Langerhans cell histiocytosis (LCH) is a rare reactive and proliferative disease of histiocytes. The disease occurs predominantly in children and rarely in adults. This disease of unknown etiology exhibits extreme clinical heterogeneity. Even though LCH manifests initially in the oral cavity in most of the cases, owing to the relative rarity of the condition, it remains a disease in which the diagnosis is often delayed, missed or misdiagnosed. This is a case of LCH in a child which presented with swelling in the mandibular region.

[Eosinophilic granuloma of the parietal bone of an adult patient with BRAF mutation]

The paper describes a case of eosinophilic granuloma of the parietal bone in a 32-year-old man. Histological examination revealed a large number of bean-shaped Langerhans cell histiocytes with lobed nuclei and nuclear grooves. The histiocytes alternated with the foci of obvious eosinophilic infiltration and with eosinophilic microabscesses. There were osteoclast-like multinucleated giant cells, bone resorption, and numerous bone rods covered with osteoblast chains. The histiocytes expressed CD1α, langerin, CD68, S100, and p53 (in 90.0% of the tumor cells). The Ki-67 proliferation index was 18.0%. A molecular genetic study identified BRAFV600E mutation (nucleotide substitution s.1799 T>A (p.V600E) in the heterozygous state). Clinical and morphological data and the results of molecular genetic studies led to the conclusion that there was eosinophilic granuloma of the right parietal bone (the unifocal form of Langerhans cell histiocytosis (LCH), type I, group A1, with the monoossal nature of lesion and with BRAFV600E mutation). In adults, this disease is extremely rare (2-5 cases of LCH per million people, bone loss in the fourth decade of life in 2.5% of the patients).