Sarcoma histiocítico en intestino delgado: estudio y discusión de un caso con reordenamiento clonal linfoide B

Histiocytic sarcoma is a rare malignant tumour of unknown pathogenesis characterized by proliferation of neoplastic cells morphologically and immunophenotypically similar to mature tissue histiocytes. There are only a few reported cases, but they have been described in both males and females of all ages and with nodal and extranodal involvement. A close relationship has often been observed with other haematolymphoid neoplasms which might provide clues to its etiology and pathogenesis. To date, diagnosis is by exclusion of other entities. The clinical course usually progresses rapidly and an effective therapeutic regime has not yet been established. We report a case in an 82 year old male who had suffered a perforation of the jejunal loop and was found to have a malignant tumour infiltrating the wall of the small bowel. The tumour was positive only for CD68, CD45RO, CD163, lysozyme and vimentin and showed a B lymphoid clonal rearrangement with little amplification.