Diagnostic Criteria of Hemophagocytic Lymphohistiocytosis (HLH)

Hemophagocytic lymphohistiocytosis (HLH) is a frequently fatal and likely underdiagnosed disease involving a final common pathway of hypercytokinemia, which can result in end-organ damage and death.
Although an early diagnosis is crucial to decrease mortality, the definitive diagnosis is often challenging because of the lack of specificity of currently accepted diagnostic criteria and the absence of confirmatory gold standards. Continue reading

Diagnostic Criteria of Langerhans Cell Histiocytosis (LCH)

The diagnosis of Langerhans Cell Histiocytosis (LCH) is based on histological and immunophenotypic examination of lesional tissue. The main feature is the morphologic identification of the characteristic LCH cells. Additionally, positive staining of the lesional cells with CD1a and/or Langerin (CD207) is required for definitive diagnosis. Continue reading

Criteria for the Diagnosis of POEMS Syndrome

POEMS syndrome is a rare paraneoplastic syndrome due to an underlying plasma cell disorder (PCD). The acronym, which was coined by Bardwick in 1980, refers to several, but not all, of the features of the syndrome: polyradiculoneuropathy, organomegaly, endocrinopathy, monoclonal PCD, and skin changes. Continue reading

Revised IMWG Diagnostic Criteria for Multiple Myeloma

The International Myeloma Working Group (IMWG) consensus updates the disease definition of multiple myeloma to include validated biomarkers in addition to existing requirements of attributable CRAB features (hypercalcaemia, renal failure, anaemia, and bone lesions). Continue reading

Diagnosis of Porphyria

The porphyrias are disorders of heme synthesis, which has eight steps. Each type of porphyria involves a defect, either inherited or acquired, in a pathway enzyme. When the defect is physiologically significant, it results in overproduction of pathway precursors preceding the defective step which enter the circulation and are excreted into urine or bile. The diseases have been grouped as acute hepatic porphyrias and photocutaneous porphyrias. The acute porphyrias are due to hepatic overproduction of the porphyrin precursors, delta aminolevulinic acid and porphobilinogen, and the symptoms are caused by injury primarily to the nervous system. Cutaneous porphyria is due to overproduction of photosensitizing porphyrins by the liver or bone marrow, depending on the type of porphyria.

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WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues

The World Health Organization classification of lymphoid neoplasms updated in 2008 represents a worldwide consensus on the diagnosis of these tumors and is based on the recognition of distinct diseases, using a multidisciplinary approach.

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Features of the Thalassemias

The thalassemias are a group of inherited hematologic disorders caused by defects in the synthesis of one or more of the hemoglobin chains. Alpha thalassemia is caused by reduced or absent synthesis of alpha globin chains, and beta thalassemia is caused by reduced or absent synthesis of beta globin chains. Imbalances of globin chains cause hemolysis and impair erythropoiesis.

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