Thrombocytosis. Etiologic analysis of 663 patients.

Six hundred sixty-three children aged 1 to 16 years with thrombocytosis (defined as a platelet count of more than 500 x 10(9)/L) seen in a university hospital over a 1-year period were studied prospectively for etiology. The causes of thrombocytosis were infection (30.6%), hemolytic anemia (19.

Pancytopenia in children with brucellosis: clinical manifestations and bone marrow findings.

Among 276 paediatric cases of brucellosis seen over a 7-year period, 16 patients (5.8%) with pancytopenia were identified. The most frequent presentations were fever, malaise, anorexia, weight loss, arthralgia, and hepatosplenomegaly.

Pernicious anemia in Saudi Arabs.

Over a five-year period extending from January 1986 to December 1990, seven cases of pernicious anemia in Saudi patients were diagnosed at King Khalid University Hospital in Riyadh. There were five males and two females. The age range was 45 to 73 with a mean age of 61 years.

Thrombocytosis in adults: analysis of 777 patients.

A total of 777 patients with thrombocytosis, defined as a platelet count of greater than 500 x 10(9)l-1, seen in a University hospital over a 1-year period, were studied prospectively for aetiology. The most frequent causes of thrombocytosis were infection (21.9%), rebound thrombocytosis (19.

Identification of the hairy cells of leukaemic reticuloendotheliosis by an esterase method.

A distinctive pattern of alpha-naphthyl butyrate esterase positivity was observed in all of a series of 14 patients with HCL. This pattern was not observed in a range of other haematological malignancies including nine cases of CLL, two cases of Sézary's syndrome, six cases of null cell ALL, two cases of Schilling-type monocytic leukaemia and one case of lymphosarcoma cell leukaemia. The potential diagnostic value of this simple cytochemical test is discussed in relation to existing methods.

Hairy-cell leukemia with T-cell features.

A case of clinically and hematologically typical hairy-cell leukemia has been presented in which, at the various times of testing, 52%-95% of peripheral blood and 73% of splenic mononuclear cells formed spontaneous sheep erythrocyte (E) rosettes. Many of the rosetting cells were shown to be typical morphologic hairy cells by light and electron microscopy. It was found that 70%-75% of peripheral blood mononuclear cells stained with an anti-T antiserum, and this antiserum also abolished E-rosette formation.

Surface marker and other characteristics of Gaucher's cells.

A full surface marker study of the splenic storage cells in a case of Gaucher's disease largely substantiates the monocyte/histiocyte nature of Gaucher's cells. In addition, an apparent T-lymphocyte deficiency is demonstrated in the spleen and peripheral blood, and the possible significance of this finding is discussed.

Discrimination of B, T and null lymphocytes by esterase cytochemistry.

A technique has been devised which optimally demonstrates non-specific esterase activity in human blood lymphocytes. The reaction is carried out on smears fixed with formalin vapour, using alpha-naphthol butyrate as substrate at pH 8 and at a low concentration for a short incubation period. The pattern of esterase activity revealed by this method provides a discriminating marker for mature T-lymphocytes, which show dense, localised, dot-like positivity, and a probable marker for 'null' cells in the form of scattered granular positivity.