Types of Non Hodgkin,s lymphoma

Non Hodgkin's lymphoma are the cancer of lymphocytes and more commonly seen in children, most of the cases are of B cell origin but few may be of T cell origin. Viral etiology has been seen in some of its type. Immunosuppression is the most common risk factor involved. Details regarding causes and risk factors may be seen at Non Hodgkin's lymphoma : A cancer of immune system

There are many variants or types of Non Hodgkin's lymphoma, out of which Burkitt's lymphoma is the most common one and constitutes about 40% of all childhood lymphoma. The common type of Non Hodgkin's lymphoma are -

Lymphoblastic lymphoma

It is the second most commonest lype of childhood lymphoma and constitute 30% of all childhood lymphoma. In this type the bone marrow is involved at very earlier stage. It presents as a mediastinal mass in most of the cases.

The most common presenting features are rapidly enlaging neck and mediastinal lymph adenopathy. This lymphoma is though of B cell origin but has a tendency to progress into T cell acute lymphatic leukemia. Tdt is a tumor marker and may be present in all cases when investigated.

The prognosis of this type of Non Hodgkin,s lymphoma is very poor.

Burkitt's lymphoma

Burkitt's lymphoma is the fastest growing human cancer and constitute 40% of all Non Hodgkin's lymphoma. It is caused by Epstein Barr virus and the most common presentation of its endemic form also called African type is in the form of jaw tumor which involves maxilla and mandible.

In non endemic form or sporadic type it presents as abdominal tumor most commonly and then tumor of head and neck.

Lymph node invlovement in this type of lymphoma is rare. There may be a chromosomal translocation of 8 ; 14 and can be detected in chromosomal analysis.

Large cell lymphoma

It is also one of the common type of childhood lymphoma, the most common sub type being anaplastic one. The most common primary sites involved in this lymph node cancer are nasopharynx, Waldeyer ring of oropharynx ring made by lymph nodes, cervical nodes and skin.

The the involvement of bone marrow is relatively uncommon in this lymphoma but there is greater frequency of extranodal and visceral involvement and the most common organ involved is stomach.

Small lymphocytic lymphoma

This type of lymphoma cherish for its long survival and better prognosis though bone marrow involvement is almost in all cases. It occurs primarily in older age group and it is a low grade lymphoma that does hve any follicular architecture.

This type of lymphoma is often misdiagnosed by chronic lymphocytic leukemia and Waldenstorms macroglobulinemia and should be differetiated from that.

This type of lymphoma has an indolent course and a better survival rate.

Follicular lymphoma

This is the most common type of Non Hodgkin's lymphoma seen in adults and it presents as a generalised painless lymphadenopathy. At the time of diagnosis bone marrow involvement is seen in most of the cases. Involvement of extranodal site is uncommon.

It has a characteristic t 14 ; 18 translocation of chromosome and may be detected by chrosomal analysis. This lymphoma though have an indolent course but is stubborn in nature and difficult to cure.

Adult T cell lymphoma

Adult T cell lymphoma is caused by retrovirus HLTV 1. It may presents with features like skin lesion which may resemble lesions like in mycosis fungoides, there may be enlarged spleen and liver. Generalised lymphadenopathy may be seen. There may be lytic bone lesions and increased calcium level in blood.

This type of lymphoma may be diagnosed by seeing increased serum LDH level, increased serum level of CD25 which is the tumor marker of this cancer.

The patient suffering from adult T cell lymphoma are more susceptible to oppotunistic infections with Pneumocystis carnii and other fungi as the virus belongs to same group as of HIV AIDS virus.

Cutaneous T cell lymphoma

Cutaneous T cell lymphoma consists of two variants called mycosis fungoides and sezary syndrome and is characterised by cutaneous or skin lesions and lymphadenopathy. It is considered as a tumor of peripheral CD4 and T cells.

Sezary syndrome is infilteration of bone marrow and peripheral blood with circulating leukemia cells called sezary cells in presence of generalised exfoliative erythroderma.

Secondary infection is most frequent in this type of lymphoma and may be the most common reason of death. Treatment is required locally for skin lesions as well as systemic.

AIDS related lymphoma

These are high graded lymphoma and is present in AIDS as diffuse histiocytic or immunoblastic type. Non Hodgkin's lymphoma occurs in 10 to 30% cases of AIDS. Here again extranodal involvement is very common and central nervous system is most commonly involved followed by gastrointestinal tract.

Opportunistic infections are common as there is already immunosuppression and this is the major reason of death in patients suffering from AIDS related lymphoma.

Though there are many classification according to grade of histology, but the major types and a brief about them has been described here.