Myelofibrosis, hepatic extramedullary hematopoiesis and ascites associated with vitamin D deficiency in early infancy.

Primary myelofibrosis is rare in children. Many causes have been described for secondary myelofibrosis including vitamin D deficiency. Here, we describe a patient with myelofibrosis secondary to vitamin D deficiency, as diagnosed by laboratory evidence. The patient also developed resultant extramedullary hematopoiesis with secondary development of ascites as a result of myelofibrosis. These are findings rarely reported in association with vitamin D deficiency. Potential mechanisms are also discussed.