Radiological and clinical patterns of myeloid sarcoma

Abstract

Background Myeloid sarcoma (MS), also known as granulocytic sarcoma or chloroma, is a solid tumor of extramedullary localization composed of malignant primitive myeloid cells. The purpose of the study was to identify clinical and imaging features in a large patient sample. Patients and methods Overall, 71 cases (34 females (47.9%) and 37 males (52.1%) with a median age of 56 (± 16 years) of histopathologically confirmed myeloid sarcoma were included into this study. The underlying hematological disease, occurrence, localizations and clinical symptoms as well as imaging features on computed tomography and magnetic resonance imaging were investigated. Results In 4 cases (5.63%) the manifestation of MS preceded the systemic hematological disease by a mean value of 3.8 ± 2.1 months. In 13 cases, first presentation of MS occurred simultaneously with the initial diagnosis of leukemia, and 51 patients presented MS after the initial diagnosis of the underlying malignancy with a mean latency of 39.8 ± 44.9 SD months. The visceral soft tissue was affected in 26 cases, followed by the cutis/subcutis was affected in 21 cases. Further localizations were bones (n = 13), central nervous system (n = 9), lymph nodes (n = 4) and visceral organs (n = 9). Conclusions MS is a rare complication of several hematological malignancies, predominantly of acute myeloid leukemia, which can affect any part of the body. In most cases it occurs after the diagnosis of the underlying malignancy, and affects frequently the cutis and subcutis.

Keywords: acute myeloid leukaemia; chloroma; granulocytic sarcoma; myeloid sarcoma.

Figure 1

Computed tomography in a 89-years old patient with chronic myeloid leukemia showing a large abdominal mass (arrow) affecting the small bowel. Histological examination (not shown) after surgical biopsy confirms an extramedullary relapse of the known leukemia.

Figure 2

Magnetic resonance imaging findings in a 32-years old patient with known history of acute myeloid leukemia. Clinical presentation with headache. MRI documenting a large lesion in the left temporal lobe (arrows). On T1 weighted image it is slightly hypointense (A). After intravenous application of contrast medium, the lesion shows an inhomogenous enhancement (B). Histological examination (not shown) after surgical biopsy confirms an extramedullary relapse of the known leukemia.

Figure 3

Axial T2 weighted image of the pelvis documenting multiple slightly hyperintense intramuscular lesions (arrows) in a 59-years old patient with known history of acute myeloid leukemia.

Figure 4

Computed tomography of the thorax (A) and abdomen in portal venous phase (B) in a 54-years old patient with acute myeloid leukemia documenting multiple paravertebral and retroperitoneal enhancing masses (arrows). Additionally, pleural and pericardial effusions are seen.