Unique Eosinophil Granules in a Case of T‐Cell Lymphoma

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Abstract
A 41 yr old man developed intense itching without visible cutaneous changes, epigastric pressure pain and a slight intolerance to alcohol. He had persistent blood eosinophilia. The eosinophil granulocytes were of abnormal appearance in the light microscope: larger than normal, the nuclei were multilobulated (4-6 lobes), the cytoplasm contained atypical, large granules, ample glycogen and up to 12 vacuoles. In EM the eosinophil granules were atypical, having an electron-dense matrix, often with a light central inclusion body which was inhomogeneous, having longitudinally oriented structures with a periodicity of about 10 nm. These findings are contrary to normal eosinophil granules. Studies of cytoplasmic enzymes from the granulocytes revealed a greatly reduced content of eosinophil cationic proteins, whereas 5 other enzymes were present in a normal or slightly reduced quantity. The phagocytic capacity of the eosinophils against latex particles was normal. The patient developed generalized lymphomas, histologically malignant, of the convoluted, acid phosphatase positive cell type (T[thymus-derived]-cell lymphoma). Subpopulation studies of lymphocytes from a lymph node revealed 58% T cells, while the remainder were B [bone marrow-derived] cells. At death, 3 1/2 yr after the onset of symptoms, severe endomyocardial fibrosis was found. The thymus could not be identified. Lymphomas should be described on the basis of clinical, histological and histochemical criteria as well as studies of lymphocyte subpopulation and the highly unusual eosinophil granulocytes still deserve particular attention. Endocardial fibrosis is assumed to have been due to substances liberated from the eosinophil cells.