Ibrahim, Muntaser E.Alfarouk, Khalid OmerYousif, Sabahetal.Molecular Biology2015-11-182015-11-182015-11-182015http://khartoumspace.uofk.edu/123456789/17226A 66 year o ld male with a long standing uncontrolled gastric H pylori infection and Crohn’s disease presented with nodular lesions in the back. These were removed surgically. Pathologically the lesion consisted of lymphocytes, giant cells with vacuolated cytoplasm and histiocytes. By immunohistochemistry there were stem cells, B cells and CD1a Langerhans cells. The diagnosis of Langerhans histiocytosis was made. The giant cells were positive for both CD 20 B cell marker and the macrophage marker CD 68 indicating that they were derived from B cells. They were strongly positive for H pylori antigen. A year later the patient reported with non-itching nodular lesions in the right flank. There was no lymphadenopathy or Splenomegaly. A biopsy of the lesion showed a follicular center B cell lymphoma. The tumor cells were positive for H pylori antigen. He was treated for H pylori infection. He completely recovered and was in good health a year later.enLangerhans Histiocytosis, H. pylori infection, Cutaneous Follicular B cell lymphomaPublication