SEER Inquiry System - Question 20210053 Details

2021 Bone marrow biopsy showed erythroid hyperplasia, increased histiocytes with hemophagocytosis and Factor XIIIa positive histocytic cells. Moderate cytoplasmic staining for ALK 1, consistent with bone marrow involvement of ALK-positive histiocytosis. A subsequent kidney lesion biopsy was also found to have ALK-positive histiocytosis. The patient was then treated with clofarabine.

Patient is 3 years old.

07/2020-Chart indicates patient presented in June with fevers and refusing to walk with pancytopenia, bone marrow biopsy showed no leukemia buthistiocytes. Impression: ALK positive histiocytosis involving BM and kidney.

10/2020 Bone marrow final diagnosis states right and left bone marrow aspirates and biopsies: No morphologic or immunohistochemical evidence of involvement by the patient's previously diagnosed ALK+ histiocytosis (see Comments) - Multiple histiocytic collections with prominent hemosiderin; favor reactive - background normocellular bone marrow with maturing trilineage hematopoiesis.

The patient's prior bone marrow samples are reviewed (9/2020 and 7/2020). Similar to the September bone marrow sample, the current marrow shows numerous histiocyte collections with abundant associated hemosiderin deposition. These histiocytes have a stellate/dendritic appearance and lack the atypical features noted in the patient's marrow at diagnosis, favoring a reactive process. This impression is further supported by the lack of immunoreactivity for either Factor XIIIa or ALK1 among these cells. There is no convincing morphologic or immunohistochemical evidence of marrow involvement by the patient's previously diagnosed ALK+ histiocytosis within the sampled material. Of note, the marrow otherwise appears normocellular for the patient's age, indicative of ongoing marrow recovery post therapy.

It is not clear whether this would be equivalent to Langerhans cell histiocytosis, disseminated (9751/3) as there is not a statement of Langerhans cell or whether this is just histiocytosis, NOS and not reportable.