WBC 7300 Hb 12 4 Mcv 68 6

WBC: 7300 Hb: 12. 4 Mcv: 68. 6 Mch : 20 PLT : 330000 ESR : 23 CRP : ++ ESR: 22 uric Acid : 9. 2 Cr : 0. 4 Ca : 8. 3 P : 5. 4 AST: 73 ALT: 29 LDH: 984 ALP: 325 WBC: 69000 Hb: 12. 2 MCV : 64 MCH : 24 PLT : 355000 CRP : +++

A large tissue mass(7*6 cm)in the proximal left arm with bone marrow edema in the proximal metaphisial of humerous is seen

Abnormal increase uptake is seem in upper portion of left humerus-upper portion of left femur. reminder of skeleton is visualized with normal uptake Imperison: 1 -Active lesion inmention region 2 - bone scan finding high suggestive with bone metastase or systemic bone disease

Pathology : Malignant lymphoma, diffuse large cell type left arm IHC CD 20 + CD 3 + Positive In Some Background Lymphocyte CD 45 + CD 99 +

Differential Diagnosis Osteosarcoma is the most common primary malignant tumor arising in bone (myeloma excluded). Osteosarcoma, which is most common in the second and third decades of life, is usually a high-grade malignancy, . There is usually a mixture of radiodense and radiolucent areas, with periosteal new bone formation, and sometimes formation of Codman's triangl

Ewing sarcoma The characteristic periosteal reaction produces layers of reactive bone, deposited in an "onion peel" appearance.

Other tumors – Other malignant tumors that should be considered in the differential diagnosis of a primary lytic lesion include: fibrosarcoma (spindle cell sarcoma), which tends to resemble osteosarcoma but without ossification, primary lymphoma of bone metastasis from a non-bone tumor

. • "Benign" bone tumors that can present as lytic lesions include: • hemangioma, • various types of cysts, • lipomas, • eosinophilic granuloma • giant cell tumor of bone. • Destructive eosinophilic granulomas usually occur at a younger age and are not associated with a sizable soft tissue mass

Primary bone lymphoma (PBL) is an uncommon tumor accounting for approximately 4 -5% of extra nodal lymphoma and less than 1% of all non. Hodgkin's lymphoma. Disease may be complicated at presentation by pathological fracture or spinal cord compression. Diffuse large-B-cell lymphoma (DLBCL) accounts for the majority of cases of PBL.

To be defined as primary bone lymphoma (also known as Coley's criteria), there should be [4] (i) a primary focus in a single bone (ii) positive histological diagnosis (iii) no evidence of distant soft tissue or distant lymph node involvement. it is recognized that primary bone lymphoma may involve multiple bones, as long as the other two criteria are met

PBL occurs commonly between 20 and 50 years of age and shows male preponderance with male to female ratio of 3: 2. The femur (29%) is the most common site followed by (in descending order of frequency): pelvis (19%), humerus (13%), skull (11%) and tibia (10%).

Clinical presentation • Clinical presentation includes local pain and swelling. Radiologically bony lesions may be extensive, destructive or infiltrative. • Extensive lesions involve 25 -50% of affected bone, sometimes entire bone. • Destructive lesions are radiolucent, mottled, patchy, moth eaten and sometimes the outline of the bone is completely lost

Nearly all variants destroy cortical bone and 25% thicken the cortex. Often large, obvious soft-tissue extension may be present along with bony lesion. Diagnosis is established by biopsy.

• Other investigations include skeletal survey, bone scan, bone marrow biopsy, CT scan of whole abdomen and chest to assess lymph node involvement and serum LDH estimation are done as part of the staging procedure. MRI is helpful in demonstrating bone marrow and soft tissue involvement. Lymphoma has an increased uptake on bone scan.

treatment Over the last two decades, chemotherapy (CHOP based) has become the standard treatment with or without consolidative irradiation. The introduction of rituximab since March 2001 has been accompanied by a remarkable improvement in the PFS for patients with PBL compared with those treated earlier without rituximab (3 -year PFS 88% versus 52%). Role of radiation in advanced stage PBL is controversial. Surgery is only indicated for pathologic fractures

Thus, primary lymphoma of bone should be considered in the differential diagnosis of bony tumors in young patients in second to fourth decade. Chemotherapy followed by radiotherapy is the treatment of choice and is associated with good outcome