Variola Equina (Horse-Pox)

Abstract

The new onset of pancytopenia often creates a diagnostic dilemma to the treating physician and leads to bone marrow biopsy and aspiration. To determine the distribution of bone marrow findings in such cases of new-onset pancytopenia in a tertiary academic medical center, we evaluated 250 recent bone marrow aspirates and biopsies performed in the setting of new-onset pancytopenia in patients without previously diagnosed hematologic neoplastic disease. Of the 250 bone marrow studies, 193 were performed in adults and 57 were performed in children. In children, the most prevalent bone marrow finding was B-lymphoblastic leukemia, followed by nonspecific changes attributed clinically to a variety of factors including multifactorial, autoimmune, inflammatory, and infectious etiologies. In adults, hematologic neoplastic causes of pancytopenia were the most prevalent diagnoses, with the cases divided mostly between acute myeloid leukemia and myelodysplastic syndrome, with fewer numbers of cases of acute lymphoblastic leukemia, myeloproliferative neoplasms, and lymphomas. Many bone marrow findings demonstrated nonspecific changes that were attributed clinically to a variety of etiologies such as myelodysplastic syndrome, multifactorial causes, hypersplenism, drugs, and systemic disease. Overall, in both the pediatric and the adult population, new-onset pancytopenia was most commonly associated with neoplasia, although the neoplasm differed by age group. Although in most cases, a definitive diagnosis could be made based solely on bone marrow aspirate and biopsy interpretation, a significant fraction of cases in both children and adults demonstrated nonspecific marrow findings that required clinical follow-up and/or repeat biopsy for definitive diagnosis.