IS Case 82: Large B Cell Lymphoma
Imaging Sciences URMC 2008
Publication Date: 2009-05-20
History
A 57-year-old female with progressive right thigh pain over the last 3 to 4 months, now presents with significant pain with weight bearing pain. She denied having any trauma or any mechanical symptoms. She has developed significant soft tissue swelling and some induration of the soft tissues of the distal 1/3 of the thigh.
Discussion
Primary bone lymphoma accounts for less than 5% of all primary bone tumors. The radiographic appearances of primary bone lymphoma are variable, and the lesion can appear near normal on plain radiographs. Our patient has a classic clinical and radiological presentation of primary bone lymphoma. She is within the median age range of 36-62 years and presented with classic symptoms of insidious and intermittent bone pain in the femur, which is the most common site of involvement. Plain film and CT show a solitary, permeative, metadiaphyseal lytic lesion with extensive layered periosteal reaction, findings highly suggestive for malignant tumor. Radiographically the differential diagnosis for this age group includes osteosarcoma, metastatic disease and including lymphoma.
MR shows a soft-tissue mass involving the marrow and extending through the cortex into adjacent soft tissues. Bone marrow replacement on MR narrows the differential to small, round, blue cell tumors, such as lymphoma and Ewing sarcoma. Between these two tumors the patient's age determines their relative likelihood, with Ewing sarcoma being more likely in patients younger than 30 years old.
Bone scan and PET imaging are used to evaluate for metastatic or multifocal involvement. In this case, bone scan reveals increased perfusion, blood pool and uptake in the region of the tumor. These features reflect the increased vascular demand of the tumor and increased bone remodeling secondary to bone destruction by the tumor. These findings could also be seen in Paget's disease and osteomyelitis.
Primary bone lymphoma has a better prognosis than many other malignant bone tumors. In general, patients with monostotic primary bone lymphoma do well when treated with a combination of radiation therapy and chemotherapy.
References
- Krishnan A, Shirkhoda A, Tehranzadeh J, et al. Primary bone lymphoma: radiographic-MR imaging correlation. Radiographics. 2003 Nov-Dec;23(6):1371-83; discussion 1384-7. [PMID: 14615550]
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