The malignancies of the lymphoid system are called the lymphomas. They are a fairly common variety of cancers whose incidence has rapidly grown during the past few decades, principally due to the increase in the number of immunocompromised hosts. Non-Hodgkin’s lymphoma is one type of lymphomas whose pathogenesis is triggered by various etiological factors. Hodgkin’s lymphoma is the other type. Therefore, the difference between lymphoma and Non Hodgkin’s lymphoma arises from the fact that lymphoma includes both Hodgkin’s and Non-Hodgkin’s lymphoma and Non-Hodgkin’s lymphoma just is one type. Hence, here, we have mainly discussed the difference between Hodgkin’s and Non-Hodgkin’s lymphoma.
CONTENTS
1. Overview and Key Difference
2. What is Lymphoma (Hodgkin’s and Non-Hodgkin’s Lymphoma)
3. What is Non Hodgkin’s Lymphoma
4. Similarities Between Lymphoma and Non Hodgkin’s Lymphoma
5. Side by Side Comparison – Hodgkin’s vs Non Hodgkin’s Lymphoma in Tabular Form
6. Summary
What is Lymphoma?
Malignancies of the lymphoid system are called lymphomas. They can arise at any site where lymphoid tissues are present. It is the 5th most common malignancy in the Western world. The overall incidence of lymphoma is 15-20 per 100000. Peripheral lymphadenopathy is the commonest symptom. However, in about 20% of the cases, lymphadenopathy of the primary extranodal sites is observed. In a minority of patients, lymphoma associated B symptoms such as weight loss, fever, and sweats may appear. According to the WHO classification, lymphomas can be divided into two categories as Hodgkin’s lymphoma and Non-Hodgkin’s lymphoma.
What is Hodgkin’s Lymphoma?
The incidence of Hodgkin’s lymphomas is 3 per 100000 in the Western world. This broad category can be subclassified into smaller groups as Classical HL and Nodular Lymphocyte-predominant HL. In the Classical HL, which accounts for 90-95% of cases, the hallmark feature is the Reed-Sternberg cell. In Nodular Lymphocyte Predominant HL, “popcorn cell”, a variant of the Reed-Sternberg can be observed under the microscope.
Etiology
Epstein-Barr Virus (EBV) DNA has been found in tissues from patients with Hodgkin’s lymphoma.
Figure 01: Vital Lymph Nodes of the Body
Clinical Features
Painless cervical lymphadenopathy is the commonest presentation of HL. These tumors are rubbery on examination. A small proportion of patients may present with a cough due to the mediastinal lymphadenopathy. Some may develop pruritus and alcohol-related pain at the site of lymphadenopathy.
Investigations
- Chest X-ray for mediastinal widening
- CT scan of chest, abdomen, pelvis, neck
- PET scan
- Bone marrow biopsy
- Blood counts
Management
The recent advances in the medical sciences have improved the prognosis of this condition. Treatment in the early stage of the disease includes 2-4 cycles of doxorubicin, bleomycin, vinblastine and dacarbazine, non-sterilizing, followed by irradiation, which has shown more than 90% cure rate.
Advanced disease can be treated with 6-8 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine along with chemotherapy.
What is Non Hodgkin’s Lymphoma?
As mentioned at the beginning, Non- Hodgkin Lymphomas are one variety of lymphomas. According to the WHO classification, 80% of Non-Hodgkin’s lymphomas are of B-cell origin and the others are of T-cell origin.
Etiology
- Family history
- Human T-cell Leukemia Virus type-1
- Helicobacter pylori
- Chlamydia psittaci
- EBV
- Immunosuppressant drugs and infections
Pathogenesis
During different stages of lymphocyte development, malignant clonal expansion of lymphocytes can happen giving rise to different forms of lymphomas. Errors in the class switching or gene recombination for immunoglobulin and T cell receptors are the precursor lesions that later progress into malignant transformations.
Types of NHL
- Follicular
- Lymphoplasmacytic
- Mantle cell
- Diffuse large B cell
- Burkitt’s
- Anaplastic
Figure 02: Intermediate Magnification Micrograph of Mantle Cell Lymphoma of the Terminal Ileum
Clinical Features
The commonest clinical presentation is painless lymphadenopathy or symptoms that occur due to the mechanical disturbances by the lymph node mass.
What is the Similarity Between Lymphoma and Non Hodgkin’s Lymphoma?
- In both conditions, the malignancies arise in the lymphoid tissues.
What is the Difference Between Lymphoma and Non Hodgkin’s Lymphoma?
Lymphomas can be divided into two categories as Hodgkin’s and Non-Hodgkin’s lymphomas. As non Hodgkin’s lymphomas are only a variety of lymphomas, there is no significant difference to discuss; hence, we have compared here the difference between Hodgkin’s and Non-Hodgkin’s lymphomas.
What is the Difference Between Hodgkin’s Lymphoma and Non-Hodgkin’s Lymphoma?
Hodgkin’s Lymphoma vs Non-Hodgkin’s Lymphoma |
|
| Most of the time, these are localized to a single axial group of nodes such as cervical and mediastinal nodes. | Peripheral nodes are more likely to be affected by Non-Hodgkin lymphomas. |
| Spread | |
| There is an orderly spread by contiguity. | There is noncontiguous spread. |
| Extranodal Presentation | |
| Extranodal presentation is rare. | Extranodal presentation is common. |
| Causes | |
| The Epstein Barr Virus is the most common etiological agent. | The most frequent causes are,
|
| Clinical Presentation | |
| Painless cervical lymphadenopathy is the commonest presentation of HL.
These tumors are rubbery on examination. A small proportion of patients may present with a cough due to the mediastinal lymphadenopathy. Some may develop pruritus and alcohol-related pain at the site of lymphadenopathy. |
The commonest clinical presentation is painless lymphadenopathy or symptoms that occur due to the mechanical disturbances by the lymph node mass. |
Summary – Lymphoma vs Non Hodgkin’s Lymphoma
Lymphomas are the malignancies of the lymphoid tissues. There are two main categories of lymphomas; they are Hodgkin lymphomas and Non-Hodgkin lymphomas. The prognosis of these malignancies depends on the stage of disease progression and the cells of origin.
References:
1. Kumar, Parveen J., and Michael L. Clark. Kumar & Clark clinical medicine. Edinburgh: W.B. Saunders, 2009.
Image Courtesy:
1. “Diagram showing the lymph nodes lymphoma most commonly develops in CRUK 311” By Cancer Research UK – Original email from CRUK (CC BY-SA 4.0) via Commons Wikimedia
2. “Mantle cell lymphoma – intermed mag” By Nephron – Own work (CC BY-SA 3.0) via Commons Wikimedia