Controlled and uncontrolled thrombocytosis. Its clinical role in essential thrombocythemia.

Only two of 19 patients with spontaneously evolving essential thrombocythemia remained asymptomatic in a 421 patient-month observation. The rest of the patients showed hemorrhagic diathesis (four patients), nonspecific neurological semiology (two patients), and occlusive vascular illness in cerebral, myocardic, arterial, and often multiple locations (total, 12 patients). Peripheral neuropathy was found in five of 10 patients studied. In this series the incidence of cerebral ischemia in the uncontrolled condition was 180 times higher than the epidemiologic expectancy in a population not affected by the disorder. Of 35 ischemic attacks, 22 occurred when the platelet count was more than than 1000 X 10(9)/l, 13 when the count ranged from 650 to 990 X 10(9)/l, and none occurred at counts of less than 650 X 10(9)/l. In contrast, therapeutic control of the thrombocytosis caused all complications to disappear. These findings point out the danger of the natural course of the illness and justify active therapy. At the same time they call into question some of the most commonly used criteria in the diagnosis of essential thrombocythemia.

Six new cases of prolymphocytic leukemia with heterogeneous prognosis. Clinical and immunologic features, light microscopy, and ultrastructural findings.

The clinical features and diagnostic evaluation of six patients affected by prolymphocytic leukemia (PLL), are described. Some of the cases deviate from a relatively uniform and aggressive clinical course of the disease entity. An actuarial survival analysis of 60 cases gathered from the literature and the authors' experience indicate that the cases showing the most prolongated evolution may reach 30% of the total. The different aggressiveness in the clinical course of these patients does not depend on the efficiency of the therapies applied. The percentage of prolymphocytes (PL) in peripheral blood throughout the clinical course was variable and not depending on the treatments used. This fact, in conjunction with (1) the presence of cellular types deviated from the typical PL and detected both at optical and ultrastructural levels and (2) the existence of cases of PL with minimal splenomegaly and leukocyte counts of less than 50 X 10(9)/liter, could lead to an underdiagnosis of PLL and hinder the actual cognition of the natural medical history of the disease.

Orbital phycomycosis.

3 cases with rhinoorbital phycomycosis and a 4th case, in which it was considered retrospectively, are presented in hematological patients. 2 of the 4 patients survived. In the first 3 cases, which appeared in a period of 2 months in the Hematology Unit, an epidemiological study was made, showing that the cause of the infections was contamination of the air-conditioning systems of this unit by numerous Phycomycetes and Mucor pusillus.