Submitting Author: Mason, Natalie Jeanne, MD
Institution: Medical University of South Carolina
Additional authors:Ana Maria Medina MD, Sarah Brooks MD, Nicole Miller DO, Michelle Hudspeth MD, John Lazarchick MD
Session: AML secondary to myeloproliferative neoplasms and other types of disease progression in MPN

A 3 year old female presented to an outside institution with persistent fevers, abdominal pain and petechia. Upon admission she was found to be pancytopenic (white blood cell count 1,100/CUMM, absolute neutrophil count 80/CUMM, hemoglobin 7.9 GM/DL, platelets 8/CUMM). She had splenomegaly and antibiotic therapy failed to resolve her fever. She was referred to our institution for further work up and a bone marrow biopsy was performed. The findings are detailed below. The patient was then admitted for bone marrow transplant. She is now one month post-transplant and doing well.

B + solution followed by 10% formalin fixation of iliac crest bone marrow biopsy

Details of microscopic findings:

A peripheral blood smear demonstrated moderate red cell anisocytosis and poikilocytosis with occasional dacrocytes and helmet cells. White blood cells were overall markedly decreased in numbers; those present were predominantly small mature-appearing lymphocytes. Rare segmented neutrophils and immature myeloid forms showed no morphologic abnormalities. Platelets were markedly decreased.

The bone marrow aspirate was hypocellular and hemodilute; it was inadequate for evaluation.

The bone marrow biopsy was 40-50% cellular with markedly dilated sinusoids and an overall streaming architecture of the cellularity. There were rare myeloid, erythroid and megakaryocytic cells identified. The cellularity was predominantly composed of lymphocytes.

A CD3 immunohistochemical stain highlighted markedly increased numbers of small T-cells. There were only scattered CD20 positive cells including two aggregates. Glycophorin, myeloperoxidase and factor VIII revealed rare erythoid, myeloid and megakaryocytic cells respectively.

Gordon and Sweet Reticulin special stain was significant for grade 3 fibrosis (MF3). Masson’s special stain highlighted thick bands of collagen fibrosis.

Flow cytometric analysis could not be performed due to the hemodilute aspirate.

Culture failure due to hemodilute aspirate.

FISH for BCR-ABL: negative.

PCR for MPL exon 10 analysis: negative.

PCR for JAK2: negative.

This is a rare case of primary myelofibrosis in a pediatric patient; it is a diagnosis generally associated with patients in the sixth to seventh decades of life. A study published in the American Journal of Hematology in May of 2012 describes pediatric patients with primary myelofibrosis collected over 27 years as a distinct molecular entity from adults (1). Of the patients tested for JAK2 and MPL mutations, all were negative, as was the case for our patient.

Source:

1. Delario, MR. “Clinical, Histopathologic, and Genetic Features of Pediatric Primary Myelofibrosis- An Entity Different From Adults.” American Journal of Hematology (2012): 461-4.

Primary myelofibrosis, fibrotic stage

Pediatric primary myelofibrosis

Case 340