1995 Volume 34 Issue 4 Pages 675-679
We report a case of malignant lymphoma occurring in the thymus, accompanied by emperipolesis in a hydrothorax. The patient was a 13-year-old female who complained of cough, nausea and loss of appetite. A chest X-ray and chest computed tomographic (CT) scan revealed hydrothorax and a mass in the anterior mediastinum. Needle biopsy of the mass lesion led to a histological diagnosis of malignan lymphoma which had. developed in the thymus and was characterized by the proliferation of small or medium size lymphoma cells showing slight atypia and by a remnant of Hussel's body. Cytologically, specimens from the hydrothorax were composed of lymphoma cells, macrophages, mesothelial cells and large cells containing lymphoma cells in their cytoplasms. The majority of intracytoplasmic cells appeared to be viable, because pyknotic nuclear materials and cell debris were rare and mitotic figures were observed. Therefore, this phenomenon was thought to be so-called “emperipolesis”, rather than phagocytosis. Immunocytochemically, host cells possessed macrophage markers including CD 68, lysozyme and so on. Lymphoma cells showed double positivity to CD 4 and CD 8, suggestive of T-lymphoblastic type. To our knowledge, no report describing emperipolesis in specimens from a hydrothorax has been published to date.
