Non Hodgkin's lymphoma

Non hodgkins lymphomas(NHL) revision.
1. Most common form of indolent NHL in United states - Follicular lymphoma.
2. Most common form of NHL - diffuse large B cell lymphoma.
3. Most common extra nodal site of NHL - stomach.
4. Most lymphoid neoplasms are of B cell origin (85-90%)
5. t (14:18) which juxtaposes IgH locus on ch.14 with bcl2 on ch.18 is seen in follicular lymphoma.
6. Two types of cells seen in follicular lymphoma are centrocytes and centroblasts.
7. Marker used for diagnosis of FL is bcl2 positive and CD 5 negative. 8. Most common site of endemic Burkitt s lymphoma - jaw or mandible.
8. Most common site of sporadic burkitt lymphoma is ileocaecum or peritoneum.
9. t (8:14) or c - myc seen in burkitt lymphoma.
10. All endemic burkitt s lymphoma are latently infected with EBV which is also present in 15 to 20% of sporadic cases.
11. Starry sky appearance due to interspersed phagocytes amongst the lymphoid cells seen in burkitt lymphoma.
12. Cells of burkitt are bcl6 positive and bcl2 negative.
13. t(11:14) seen in mantle cell lymphoma.
14. Mantle cell lymphoma shows small cleaved cells but no centroblasts.
15. Markers for mantle cell lymphoma are cyclin D1. Cells are CD5 positive and CD 23 negative. This helps to differentiate mantle cell lymphoma from CLL which shows CD5 positive and CD5 positive profile.