Myeloid sarcoma and pathological fracture: a case report and review of literature

Abstract

Myeloid sarcoma is a rare clinical entity that presents as an isolated proliferation of leukemic cells, concurrently with or at relapse of acute myeloid leukemia (AML), myelodysplastic syndromes/neoplasms (MDS), chronic myeloid leukemia (CML), and myeloproliferative neoplasm (MPN). Myeloid sarcoma disrupts the normal architecture of its surrounding tissues. When it forms in long bones, it can cause their pathological fracture. We recently experienced a rare case of MDS presenting with myeloid sarcoma in the femur that eventually resulted in its pathological fracture. Detailed chromosomal analysis of the bone marrow cells suggested emergence of myeloid sarcoma during the fast-paced progression of MDS just after acquiring trisomy 22. A comprehensive review of previous cases of myeloid sarcoma-associated pathological fracture indicated possible involvement of structural rearrangements of chromosomes 9 and 22. Management of myeloid sarcoma should continue to improve, and clinicians should note that myeloid sarcoma with specific chromosomal alterations needs extra medical attention to prevent pathological fracture.

Keywords: Myelodysplastic syndromes/neoplasms; Myeloid sarcoma; Pathological fracture.

Fig. 1

Myeloid sarcoma-associated pathological fracture. A Clonal evolution of MDS/AML cells with trisomy 22 in the bone marrow. Chromosomal analysis of the bone marrow cells showed additional chromosomal alterations including + 22 that had been observed just before the development of myeloid sarcoma in the right femur. (A-1) 45, XY, − 3, add (5)(q11.2), − 7, − 9, add(12)(p11.2), − 17, add(19)(p13.3), -20, + 22, + r, + 2mar, 2dmin. (A-2) 46, XY, add(5)(q11.2), − 7, + add(8)(q24.1), − 9, + 11, add(15)(p11.2), − 17, − 19, der(20)t(7;20), (q11.2;q13.1), + 22, + r, 2dmin. (A-3) 45, XY, − 1, add(1)(q21), − 3, add(5)(q11.2), − 7, − 9, − 12, − 17, add(19)(p13.3), − 20, + 22, + r, + 4mar, 3dmin. B Post-contrast fat-suppressed T1-weighted magnetic resonance image (MRI) of the myeloid sarcoma in the right femur presenting as an osteolytic lesion. C–E Histopathological analysis of the sample obtained from the fine needle biopsy of the myeloid sarcoma in the right femur. The Hematoxylin and Eosin (H & E)-staining revealed dense proliferation of immature myeloid cells with nuclear enlargement and high nuclear to cytoplasmic (N/C) ratio (D). The immature myeloid cells were stained positive for c-kit (E) and partially positive for CD34 (F). F Plain X-ray image of the myeloid sarcoma in the right femur presenting as a pathological fracture