Granulocytic Sarcoma in bone

Summary
Description

Granulocytic sarcoma (GS) is a solid tumor of immature granulocytes that most commonly occurs in a patient with leukemia or some other myleoproliferative disorder. Osseous lesions are most common in the skull and the orbit.

People and Age
Peak incidence occurs in the third and fourth decades of life.
Symptoms and Presentation
The majority of osseous granulocytic sarcomas present with skeletal pain referable to the location of the lesion.
Brief description of the xray
The usual finding on radiographs is lytic destruction of the cortex and the medulla with adjacent soft tissue mass and periosteal reaction.
Tumor Type
Benign or Malignant
Most Common Bones
Periosteal reaction
Complete Information on this Tumor
Introduction and Definition

Granulocytic sarcoma (GS) is a solid tumor of immature granulocytes that most commonly occurs in a patient with leukemia or some other myleoproliferative disorder, but may occasionally occur in an otherwise healthy individual.

Incidence and Demographics
Peak incidence occurs in the third and fourth decades of life. Skin, soft tissue, and lymph nodes are the most common locations of granulocytic sarcoma. Lesions of the larynx, breast,uterus, bladder, bowels, and peritoneum, and brain have been reported. Bone is a well described location of granulocytic sarcoma. Osseous lesions are most common in the skull and the orbit. Lesions have been described in the vertebrae, sacrum, rib, pelvis, sternum, clavicle, scapula, humerus, femur, and tibia. The preponderance of axial locations may be due to presence of hematogenous marrow in these sites. There is no significant difference in the distribution of location of skeletal sites between clinical presentations except for the five cases well described in patients with known CML which all occurred in the femur and tibia.
Symptoms and Presentation

The majority of osseous granulocytic sarcomas present with skeletal pain referable to the location of the lesion. This tumor has three characteristic clinical presentations: one, in an individual with no known disease where it is a harbinger of acute myelogenous leukemia; two, in an individual with already known myleoproliferative disorder. Subsequent evaluation of peripheral blood and bone marrow biopsy in this case demonstrated this to be granulocytic sarcoma without systemic evidence of acute myelogenous leukemia. The appearance of the tumor in a previously healthy individual presents a significant diagnostic challenge, and 75% of these cases are usually misdiagnosed.

X-Ray Appearance and Advanced Imaging Findings
The usual finding on radiographs is lytic destruction of the cortex and the medulla with adjacent soft tissue mass and periosteal reaction. Sclerotic lesions are unusual. Bone scans show increased radionucleotide uptake. CT usually shows mixed sclerotic and lytic processes, but also provides better imaging of associated soft tissue mass.MRI has been helpful in imaging vertebral and skeletal granulocytic sarcomas.
Histopathology findings
The tumor cells have abundant cytoplasm with variable mitotic rate, and the "starry sky" pattern is often evident. Variable amounts of eosinophilic myleocytes are seen. Myleoperoxidase and napthol cloroacetate esterase stains are specific for cells of the granulocytic series and are necessary for the correct diagnosis. Without these special stains, this tumor may be incorrectly diagnosed as Ewing's Sarcoma, non-Hodgkin's lymphoma, or Langerhans cell histiocytosis.
Treatment Options for this Tumor
Granulocytic sarcomas are treated with local radiation and AML protocol chemotherapy. Most receive aggressive chemotherapy on AML protocols. Radiation can be used to treat symptomatic bone lesions. Bone marrow transplantation has been described as a therapeutic option with good, early results.
Outcomes of Treatment and Prognosis
The prognosis for patients who present with isolated granulocytic sarcoma is improving. Long-term disease free survival of 21,50,64 and 67 months has been shown with therapy directed at AML.
Special and Unusual Features
The tumor was originally named "chloroma" by King in 1853 due to the occasional greenish color of freshly cut tumor tissue.