Granulocytic sarcoma is a localized extramedullary solid
tumor composed of immature
myeloid cell and is usually associated with
acute myeloid leukemia or
myelodysplastic syndrome. Although it can involve any site, commonly in
lymph nodes,
skin,
bone and soft
tissue, the involvement of
breast is unusual. Especially, the involvement of the
breast as a pattern of
relapse after
bone marrow transplantation is extremely rare. We have experienced 2 cases of
granulocytic sarcoma after
bone marrow transplantation. One case was a 39-year-old
woman with right
breast mass diagnosed with
granulocytic sarcoma. She had received an unrelated
bone marrow transplantation due to biphenotype acute
leukemia 3 years before our presentation. Another case was a 48-year-old
woman with
acute myeloid leukemia,
who was diagnosed with
granulocytic sarcoma on both
breasts 8 months after allogenic
bone marrow transplantation. We also discuss the clinicopathologic features of
granulocytic sarcoma in
breast after
bone marrow transplantation.