Q: What is cellular classification and why is it important?

A: NHL is classified as low, intermediate or high grade on basis of their clinical aggressiveness. Lymphomas in children are usually high grade and are classified into 4 categories.

• Burkitt's and Burkitt's like lymphoma/small non-cleaved B cell lymphoma.
  
  
• Lymphoblastic lymphoma.
  
  
• Diffuse large cell lymphoma.
  
  
• Anaplastic large cell lymphoma.
  
  

Histopathological classification of NHL in children (Table 1)

Subtype	Immunophenotype	Clinical presentation	Percentage of cases
Small non-cleaved cell (Burkitt's)	Mature B Cell.	Intra-abdominal (sporadic) jaw (endemic)	34%
Lymphoblastic Lymphoma	T cell Pre - B cell	Mediastinal or Head & neck	29%
Large cell lymphoma	B cell T cell	Variable	27%
Anaplastic large cell	T cell Null	Variable	10%

By histological classification of NHL, it helps to determine the prognosis and therapy. The prognosis is excellent in children with stage I or II NHL of any histologic subtype who receive therapy. However, for lymphoblastic NHL, longer therapy may be required. In patients with advanced disease, Burkitt's lymphoma can be adequately treated whereas patients with lymphoblastic NHL have to be treated as ALL.

Q: How is NHL treated?

A: Multiagent chemotherapy is the treatment of choice. Surgery is very limited and is usually for diagnostic purpose. Irradiation to primary sites is usually restricted to emergency situations.

Treatment for lymphoblastic lymphoma :

Stage I & II :-

• Vincristine, Doxorubicin, cyclophosphamide, prednisone, mercaptopurine, methotrexate.
  
  
• CHIP plus methotrexate - cyclophosphamide, doxorubicin, vincristine, prednisolone.
  
  
• COMP: cyclophosphamide, vincristine, methotrexate, prednisolone.
  
  

CNS prophylaxis should be given to all patients with primary tumors of the head and neck. Intrathecal methotrexate is highly effective.

Stage III :-

• LSA2L2 regime + 10 courses of methotrexate.
  
  
• CHOP + methotrexate.
  
  
• BFM - NHL 90.
  
  

Stage IV :-

• BFM - NHL 90.
  
  
• LSA2L2 + methotrexate.
  
  

*CNS prophylaxis should be given to all patients with disseminated lymphoblastic lymphoma even if CNS disease is not detectable at presentation. Here, radiation for CNS prophylaxis should be considered.

Treatment of Small Non-cleaved cell lymphoma :

Stage I & II :-

• COMP
  
  
• CHOP
  
  
• CHOP + Methotrexate.
  
  
• NHL - BFM 90.
  
  
• French LMB - 89 - High dose cyclophosphamide,high dose Methotrexate/Leucovorin,cytarabine,Vincristine,Prednisone,Doxorubicin.
  

Stage III :-

• French LMB - 89
  
  
• NHL - BFM - 90
  

Other therapies are under evaluation

Stage IV :-

• French LMB - 89
  
  
• NHL - BFM - 90
  

Other therapies are under evaluation

Treatment of Large cell lymphoma :

Stage I & II :-

• COMP
  
  
• CHOP
  

Treatment consists of a short course of combination chemotherapy with combined CNS prophylaxis for patients with head and neck primaries.

Stage III & IV :-

• APO: Doxorubicin, Prednisolone, Vincristine, Methotrexate
  
  
• ACOP+
  
  
• CHOP
  
  
• NHL - BFM 90