Primary lymphoma of the bone
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: John Fani Srour, M.D.; Maria Fernanda Villarreal, M.D. [2]
Synonyms and keywords: PLB; Reticulum cell lymphoma
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; Hodgkin disease accounting for only 6% of cases. Primary lymphoma of the bone was first discovered by Parker and Jackson in 1939. The pathogenesis of primary lymphoma of the bone is characterized by excessive osteoclast activation. Primary lymphoma of the bone is commonly located in bone marrow, axial skeleton, or femur (most common). Primary lymphoma of the bone may be classified according to location into solitary, multifocal, distant, and visceral subtypes. Mutations in BCL2 and BCL6 have been associated with the development of primary lymphoma of the bone. Primary lymphoma of the bone is rare; the prevalence of primary lymphoma of the bone is approximately 0.01 per 100,000 individuals worldwide. Primary lymphoma of the bone is more commonly observed among middle aged adults and elderly patients. MRI is the imaging modality of choice for primary lymphoma of the bone. The mainstay of therapy for primary lymphoma of the bone is chemotherapy.
Historical Perspective
Primary lymphoma of the bone was first discovered by Parker and Jackson in 1939.[1]
Classification
Primary lymphoma of the bone may be classified according to location into 4 groups:[2]
- PBL 1: solitary bone lymphoma
- PBL 2: multifocal bony lesions
- PBL 3: cases with distant nodal disease
- PBL 4: cases with visceral disease
Pathophysiology
Pathogenesis
The pathogenesis of primary lymphoma of the bone is characterized by excessive osteoclast activation.[3]
Genetics
Mutations in BCL2 and BCL6 have been associated with the development of primary lymphoma of the bone.
Gross Pathology
Common locations of primary lymphoma of the bone are in the bone marrow, axial skeleton, or femur. The metaphysis of the femur is the most commonly affected site. On gross pathology, characteristic findings of primary lymphoma of the bone include:[3]
- Fish flesh appearance of lymphoma
- Extraosseous extension and indistinct margins
Microscopic Pathology
On microscopic histopathological analysis, characteristic findings of primary lymphoma of the bone, include:[3]
- Diffuse growth pattern
- Infiltrating between bone trabeculae
- Large atypical cells
- Abundant cytoplasm
- Large bizarre cells, centroblasts, and immunoblasts
- Positive CD20 and CD79a
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:[2]
- Osteosarcoma
- Bone metastasis
- Spindle cell sarcoma
- Myeloid sarcoma
Epidemiology and Demographics
Primary lymphoma of the bone accounts for less than 5% of all primary bone tumors.
Prevalence
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.
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 factor in the development of primary lymphoma of the bone is previous exposure to radiation.[2]
Natural History, Complications and Prognosis
Natural History
- The majority of patients with primary lymphoma of the bone are symptomatic at the time of diagnosis.[2]
- Early clinical features include bone pain or a palpable mass.
- If left untreated, patients with primary lymphoma of the bone may progress to develop metastasis.
Complications
The most common complication of primary lymphoma of the bone is a pathological fracture.
Prognosis
The prognosis of primary lymphoma of the bone is generally good; the 5-year survival rate of patients with primary lymphoma of the bone is commonly >80%.[1]
Diagnosis
Symptoms
Symptoms of primary lymphoma of the bone may include the following:[2]
- Bone pain
- Limited range of motion
- Morning stiffness
- Low grade fever
- Night sweats
Physical Examination
Patients with primary lymphoma of the bone usually appear pale or malnourished. Physical examination may be remarkable for:
Laboratory Findings
There are no specific laboratory findings associated with primary lymphoma of the bone. In some cases, non-specific findings may include:[2]
- Elevated LDH
- Elevated β2 microglobulin
Imaging Findings
MRI is the imaging modality of choice for the diagnosis of primary lymphoma of the bone.
MRI
On MRI, findings of primary lymphoma of the bone include:
- Abnormalities in bone marrow
- Soft tissue mass
X ray
On conventional radiograph, the following non-specific findings of primary lymphoma of the bone may be found:[2]
- Solitary metadiaphyseal lesion
- Layered periosteal reaction
- Affected bone may be normal or affected by lytic, sclerotic or mixed pattern
- A lytic pattern with permeative bone destruction and a wide zone of transition
Treatment
Medical Therapy
The mainstay of therapy for primary lymphoma of the bone is chemotherapy combined with radiotherapy. Response to chemotherapy or radiotherapy can be monitored with imaging studies.
Surgery
Surgical intervention is not recommended among patients with primary lymphoma of the bone.
Prevention
There are no primary or secondary preventive measures available for primary lymphoma of the bone.
References
- ↑ 1.0 1.1 Choi JY, Hahn JS, Suh CO, Yang WI (2002). "Primary lymphoma of bone--survival and prognosis". Korean J. Intern. Med. 17 (3): 191–7. PMC 4531681. PMID 12298430.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Primary lymphoma of the bone. Radiopedia. http://radiopaedia.org/articles/primary-bone-lymphoma Accessed on May 1st 2016
- ↑ 3.0 3.1 3.2 Sheren Yones, M.D. Primary Lymphoma of the Bone. Pathology Outlines. http://www.pathologyoutlines.com/topic/bonelymphomageneral.html