Spectrum of Hematological Disorders in Pediatrics

Pancytopenia is a condition in which there is a decrease of all the three cellular elements of blood, namely erythrocytes, leukocytes, and platelets . It is quite a common finding among children. According to regional studies, it makes up around 2.90% to 3.57% of the burden of presentations in the pediatric population. Some of the presenting symptoms include, but are not limited to, pallor, fever, weight loss, dyspnea, bleeding, bruising, visceromegaly, and increased risk of infections .

Pancytopenia is not a disease in itself but a laboratory finding of the constitution of diseases. It can occur due to a variety of disorders which can be as simple as nutritional deficiencies to serious malignant disorders . Megaloblastic anemia and acute lymphoblastic leukemia are among the most common presentations of pancytopenia.

Pancytopenia results in a hypoplastic bone marrow. It is diagnosed on the basis of the complete blood count test. Pancytopenia is labeled when the hemoglobin (hb) is less than 10 gm%, absolute neutrophil count (anc) is less than 1.5*109/l, and platelet count is less than 100*109/l [9].

But, in order to find out the etiological factor causing pancytopenia, bone marrowexamination is done. Being an interventional procedure, it is relatively safe with little or no risk of bleeding.

Etiology of pancytopenia The etiology of pancytopenia can be broadly categorized as a central type that involves disorders of production or a peripheral type that involves disorders of increased destruction.These causes could contribute to the pancytopenia independently or as a combination.

Decreased production (central type): Pancytopenia due to decreased production is mostly secondary to nutritional deficiencies. Pancytopenia caused by bone marrow failure is known as aplastic anemia. Aplastic anemia could be idiopathic/autoimmune, secondary to infections (such as parvovirus B19, hepatitis, human immunodeficiency virus (HIV), cytomegalovirus, or Epstein-Barr virus), after drug toxicity, or chemotherapeutic agents (methotrexate, dapsone, carbimazole, carbamazepine, chloramphenicol). Pancytopenia can also be related to inadequate intake (as seen in eating disorders and alcoholics) or malabsorption.The production of cell lines is also impaired when the bone marrow is infiltrated by malignancies (lymphoma, leukemia, multiple myeloma) or granulomatous disorders. Metastatic tumors can also cause bone marrow replacement late in the disease, thus producing pancytopenia.

Increased destruction (peripheral type): Peripheral destruction of cells can be associated with many autoimmune conditions (such as systemic lupus erythematosus, rheumatoid arthritis) and splenic sequestration (alcoholic liver cirrhosis, HIV, tuberculosis, malaria). Hypersplenism affects more frequently the platelets and erythrocytes than leukocytes.

Differential diagnosis Multiple conditions can present with pancytopenia; hence, when someone shows with pancytopenia, a complete evaluation is performed to detect the cause of pancytopenia. Bone marrow disorders such as aplastic anemia, myelodysplastic syndrome, acute leukemia, myelofibrosis, megaloblastic anemia, paroxysmal nocturnal hemoglobinuria, and Fanconi's anemia can present with pancytopenia. Fanconi anemia is the most common congenital cause of bone marrow failure with an autosomal recessive inheritance pattern. In myelofibrosis, there is a replacement of the bone marrow cells with fibrotic tissue. Malignancies such as lymphoma, multiple myeloma, and hairy cell leukemia can also present with pancytopenia. Non-bone marrow conditions present with pancytopenia include systemic lupus erythematosus, infections (such as parvovirus B19, Epstein Barr virus, HIV, hepatitis, leishmaniasis, tuberculosis, malaria, and histoplasmosis).