Primary lymphoma of the bone
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Maria Fernanda Villarreal, M.D. [2]
Synonyms and keywords: PLB
Overview
Primary lymphoma of the bone (also known as "PLB" ) is an uncommon malignancy that accounts for less than 5% of all primary bone tumors. The majority of cases are of the non-Hodgkin type, with Hodgkin disease accounting for only 6% of cases.
Historical Perspective
- Primary lymphoma of the bone was first discovered by Ostrowski in 1986.
Classification
- Primary lymphoma of the bone may be classified according to location into 4 groups:
- PBL 1: solitary bone lymphoma
- PBL 2: multifocal bony lesions
- PBL 3: cases with distant nodal disease
- PBL 4: cases with visceral disease
Pathophysiology
- The pathogenesis of primary lymphoma of the bone is characterized by
- Osteoclast activating factors
- Commonly located in bone marrow, axial skeleton, or femur
- The femur is the most common site and is affected
- The mutation in BCL2 and BCL6, has been associated with the development of primary lymphoma of the bone.
- On gross pathology, characteristic findings of primary lymphoma of the bone, include:
- Fish flesh appearance of lymphoma
- Extraosseous extension and indistinct margins
- On microscopic histopathological analysis, characteristic findings of primary lymphoma of the bone, include:
Causes
- There are no established causes for primary lymphoma of the bone.
Differentiating Primary Lymphoma of the Bone from Other Diseases
- Primary lymphoma of the bone must be differentiated from other diseases that cause bone pain, fever, and limited range of motion, such as:
- Osteosarcoma
- Bone metastasis
- Spindle cell sarcoma
- Myeloid sarcoma
Epidemiology and Demographics
- Primary lymphoma of the bone is rare
- The prevalence of primary lymphoma of the bone is approximately 0.01 per 100,000 individuals worldwide.
Age
- Primary lymphoma of the bone is more commonly observed among patients aged 50 to 70 years old.
- Primary lymphoma of the bone is more commonly observed among middle aged adults and elderly patients.
Gender
- Primary lymphoma of the bone affects men more frequently than women.
Race
- There is no racial predilection for primary lymphoma of the bone.
Risk Factors
- The most common risk factors in the development of primary lymphoma of the bone is previous exposure to radiation.
Natural History, Complications and Prognosis
- The majority of patients with primary lymphoma of the bone are symptomatic at the time of diagnosis.
- Early clinical features include bone pain, or palpable mass.
- If left untreated, patients with primary lymphoma of the bone may progress to develop
- Common complications of primary lymphoma of the bone, include:
- Prognosis is generally good, and the 5-year survival rate of patients with primary lymphoma of the bone is approximately > 80%.
Diagnosis
Symptoms
- Symptoms of primary lymphoma of the bone may include the following:
- Bone pain
- Limited range of motion
- Morning stiffness
- Low grade fever
- Night sweating
Physical Examination
- Patients with primary lymphoma of the bone usually appear pale or malnourished.
- Physical examination may be remarkable for:
- Swelling
- Limited range of motion
- Gait disturbances
- Palpable mass
Laboratory Findings
- There are no specific laboratory findings associated with primary lymphoma of the bone.
- In some cases, findings may include:
- Elevated LDH
- Elevated B2 microglobulin
Imaging Findings
- MRI is the imaging modality of choice for primary lymphoma of the bone.
- On conventional radiograph, findings of primary lymphoma of the bone, include:
- Non-specific features
- Affected bone may be normal or affected by lytic, sclerotic or mixed pattern.
- The most common is a lytic pattern with permeative bone destruction and a wide zone of transition
- On MRI, findings of primary lymphoma of the bone, include:
- Abnormalities in bone marrow
Treatment
Medical Therapy
- The mainstay of therapy for primary lymphoma of the bone is chemotherapy.
- Response to chemotherapy or radiotherapy can be monitored with imaging findings.
Surgery
- Surgery is not recommended among patients with primary lymphoma of the bone.
Prevention
- There are no primary preventive measures available for primary lymphoma of the bone.