Thrombocytosis as a presenting feature of acute lymphoblastic leukemia in childhood

A "SURFin' Leukemia": Acute Lymphoblastic Leukemia Masquerading as a Syndrome of Undifferentiated Recurrent Fever

Periodic fever is not uncommon in childhood and is often ascribed to autoinflammatory conditions; however, it may be present also in children with cancer. We here describe the case of a 3-year-old boy with acute lymphoblastic leukemia who initially presented with a 4-month history of recurrent, stereotyped episodes of fever and localized joint pain, separated by completely symptom-free intervals. These symptoms were initially interpreted as a possible syndrome of undifferentiated recurrent fever until more signs of leukemia became apparent. Our report confirms that acute lymphoblastic leukemia can rarely present with periodic fever, thus possibly leading to diagnostic errors unless a high index of suspicion is maintained.

The spectrum of cavernous sinus and orbital venous thrombosis: a case and a review

Orbital venous pathologies encompass a broad range of entities including tumors, shunts, congenital anomalies, aneurysms, and obstructive lesions. Patients may present with a variety of clinical findings which may include a combination of tumefaction, vascular engorgement, orbital pulsation, and exophthalmos, depending on the relationship between the lesion and the vascular system. Clinical findings may be unreliable in excluding serious underlying disorders, and so an extensive clinical and radiologic evaluation is necessary. This article presents a rare case of spontaneous aseptic cavernous sinus-superior ophthalmic vein thrombosis in a woman on hormone replacement therapy, and illustrates the multidisciplinary approach in diagnosis and management. The literature on issues surrounding this case is reviewed.

Primary and secondary thrombocytosis in childhood

This review summarizes current data on the pathomechanisms and clinical aspects of primary and secondary thrombocytosis in childhood. Primary thrombocytosis is extremely rare in childhood, mostly diagnosed at the beginning of the second decade of life. As in adults, the criteria of the Polycythemia Vera Group are appropriate to diagnose primary thrombocytosis. The pathomechansims of non-familial forms are complex and include spontaneous formation of megakaryopoietic progenitors and increased sensitivity to thrombopoietin (Tpo). Familial forms can be caused by mutations in Tpo or Tpo receptor (c-mpl) genes. These mutations result in overexpression of Tpo, sustained intracellular signalling or disturbed regulation of circulating Tpo. Treatment of primary thrombocytosis is not recommended if platelet counts are <1500/nl and bleeding or thrombosis did not occur in patient's history. In severe cases, decision on treatment should weigh potential risks of treatment options (hydroxyurea, anagrelide) against expected benefits for preventing thrombosis or haemorrhage. Secondary thrombocytosis is frequent in children, in particular in the first decade of life. Hepatic Tpo production is stimulated in acute response reaction to a variety of disorders. Thrombosis prophylaxis is not required, even at platelet counts >1000/nl, except for cases with additional prothrombotic risk factors.

Early cerebral sinovenous thrombosis in a child with acute lymphoblastic leukemia carrying the prothrombin G20210A variant: a case report and review of the literature

This paper describes the case of a male child with acute lymphoblastic leukemia who developed cerebral sinovenous thrombosis on day 6 of induction therapy with intrathecal methotrexate and methylprednisolone. A central venous catheter had been implanted the day before. The heterozygous prothrombin G20210A variant was found together with acquired activated protein C resistance and a reduced activated partial thromboplastin time. Clinical course and magnetic resonance imaging with magnetic resonance venography gradually improved over the following days after starting anticoagulant therapy (heparin and nadroparin). Cerebral sinovenous thrombosis is a serious disease in leukemic children, occurring in up to 6% of these patients. Data from the literature are in favor of anti-coagulant treatment, even though the efficacy and safety of thromboprophylaxis during chemotherapy in leukemic children with inherited thrombophilic conditions remain to be demonstrated.

Systemic onset juvenile rheumatoid arthritis

Systemic onset juvenile rheumatoid arthritis (SoJRA) accounts for 10-20% of all JRA, affecting males and females equally and occurring most frequently under the age of 5 years. It is characterized by arthritis, daily spiking fever, an evanescent rash, serositis and a variety of other extra-articular features. Exclusion of systemic infections, malignancies and connective tissue diseases is most important in establishing the diagnosis. The disease has a wide range of severity from a short monocyclic course to a prolonged chronic course with severe destructive arthritis in approximately one third of patients. Destructive arthritis, secondary amyloidosis and treatment complications including infections, osteoporosis, growth retardation and the macrophage activation syndrome account for the significant morbidity and mortality associated with the disease. Pharmacological management includes non-steroidal anti-inflammatory drugs, corticosteroids, methotrexate and an emerging role for cyclosporine A and cytotoxic drug therapy. Elucidation of the immunopathogenetic mechanisms may lead to new targeted therapy.

Elevated plasma thrombopoietic activity in patients with metastatic cancer-related thrombocytosis

BACKGROUND AND PURPOSE

High platelet counts are occasionally seen in patients suffering from progressive malignant disorders. While granulocyte colony-stimulating factor (G-CSF) has been implicated in paraneoplastic leukemoid reactions, the stimulus for thrombocytosis is unknown. Our purpose in this study was to determine if plasma from cancer patients with thrombocytosis contains a factor or factors with thrombopoietic activity.

METHODS

We tested the effects of plasma obtained from 5 individuals with advanced tumors and high platelet counts and from 4 patients with advanced cancer and normal platelet counts on megakaryocytic differentiation of two megakaryoblastic cell lines (Dami and HEL). Differentiation was evaluated by assessing the expression of the platelet-specific cell-surface antigens CD41 (HUPL-mI) and glycoprotein IIb-IIIa using an immunocytochemical staining score. In addition, plasma samples from 7 of the 9 patients and from 5 additional cancer patients with thrombocytosis were assayed for the levels of interleukin (IL)-3, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), G-CSF, and IL-1 beta protein using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Expression of platelet-specific cell-surface antigen was increased in HEL cells after exposure to plasma from all 5 of the cancer patients with thrombocytosis, and in Dami cells after exposure to plasma from 4 of the 5. Similar, but less significant, results were found when these cells were incubated with control combinations of recombinant GM-CSF plus IL-6 or of IL-3 plus IL-6. Platelet-specific cell-surface-antigen expression was not increased in HEL or Dami cells after exposure to the plasma from the 4 cancer patients with normal platelet counts or to normal control plasma. ELISA revealed elevated levels of IL-6 in the plasma from 4 patients with thrombocytosis (38, 40, 63, and 99 pg/mL). In addition, GM-CSF concentration was high in 3 of these 4 patients (33, 47, and 127 pg/mL), and the G-CSF level was elevated in 1 (543 pg/mL). IL-1 beta and IL-3 levels were undetectable.

CONCLUSIONS

Our data suggest that the thrombocytosis observed in individuals with advanced malignant disease is mediated by a humoral mechanism. Levels of IL-6, GM-CSF, and G-CSF are elevated in some of these patients, but the plasma concentrations are generally lower than those required for in vitro induction of megakaryocytic differentiation. Plasma from patients with paraneoplastic thrombocytosis may therefore contain thrombopoietins that have not yet been identified, and which might have clinical usefulness.

Differentiation of systemic juvenile rheumatoid arthritis from acute leukemia near the onset of disease

Many children with acute leukemia have musculoskeletal complaints and non-specific hematologic abnormalities. A total of 10 children with acute leukemia and 10 with systemic juvenile rheumatoid arthritis were compared to delineate which early features could differentiate these diagnoses. Attention to evolving hematologic abnormalities and musculoskeletal findings may expedite diagnosis of these diseases.