Langerhans cell histiocytosis of the stomach with atypical morphological features

We report the unique case of a 52-year-old patient with atypical morphologi cal features of gastric Langerhans cell histiocytosis. The man was admitted because of increasing upper abdominal pain and weight loss. The upper gast rointestinal endoscopy showed a submucous, hemispherical tumor of the stoma ch wall along the lesser curvature, The tumor was completely removed and th e patient was discharged 11 days later. Two months later, he died at home. The cause of death is unknown, because the autopsy was denied by the relati ves. Macroscopically, the stomach showed a 4.5 x 2.5 cm large, spherical tu mor of the lesser curvature of the corpus, which infiltrated the perigastri c omenta and lymph nodes, the distal pancreas and the glissonian liver caps ule. The vast majority of neoplastic cells were intensely positive for S-10 0 and CD1a. Typical Birbeck granules could be identified in almost all cell s. Cell nuclei analyzed by flow cytometry showed an aneuploid peak, a featu re typically associated with malignant disease.