Neoplastic WBC III

• All lymphomas are clonal and involve lymphadenopathy and/or mass formation
• Lymphomas may or may not have a "leukemic" phase that can be detected in the peripheral blood
• Cell surface markers are necessary for diagnosis of lymphomas
• Any disease/process/drugs that disrupts the immune system predisposes the patient to lymphoma
• Normally there is a diverse mixture of B cells
• B cells of clonal neoplasms are identical due to light chain restriction
• Many B-cell lymphomas express antigens that normal B-cells do not
• Characteristic features of chronic lymphocytic leukemia are small lymphocytes, clumped chromatin and smudge cells (fragile)
• Characteristic features of small lymphocytic lymphoma include diffuse effacement of normal lymph node architecture with interspersed proliferation centers
• CLL and SLL are both negative for CD10, cyclin-D1 and FMC7 immunophenotypes
• The overall prognosis for CLL and SLL is good and only 5-10% transform to more aggressive lymphoma
• Mantle cell lymphoma is a mature B cell lymphoma composed of small lymphocytes
• t(11;14) is the diagnostic translocation for mantle cell lymphoma
• A unique feature of mantle cell lymphoma is GI mucosal involvement
• CD5, cyclin-D1 and FMC7 are pertinent positive immunophenotypes for mantle cell lymphoma
• Mantle cell lymphoma is more aggressive than CLL/SLL and does not transform
• The diagnostic test for mantle cell lymphoma is FISH: t(11;14)
• Follicular lymphoma is comprised of germinal center derived B-cells
• Follicular lymphoma is associated with a t(14;18) translocation
• Follicular lymphoma is associated with the BCL2 gene on chromosome 18 and the IGH gene on chromosome 14
• Follicular lymphoma is associated with a nodular lymph node pattern and a paratrabecular distribution in the bone marrow (30%)
• The immunophenotype for follicular lymphoma is positive for CD10, Bcl-6, and Bcl-2 which is anti-apoptotic and helps them survive longer
• Burkitt lymphoma commonly presents with diffuse lymphadenopathy
• Endemic Burkitt lymphoma follows malaria distribution and presents most often in children with a jaw mass
• Sporadic Burkitt lymphoma presents in the ileocecal valve and gonads of children and young adults (avg age 30)
• Burkitt lymphoma often presents with a loss of normal lymph node architecture and cytoplasmic vacuoles on smears
• Burkitt lymphoma is positive for CD10 and negative for Bcl-2
• The genetics associated with Burkitt lymphoma is t(8;14)
• Burkitt lymphoma grows aggressively and rapidly but is very chemosensitive with a 80-90% survival
• MALT lymphoma is an extranodal lymphoma comprised of morphologically heterogenous small B cells
• MALT lymphoma can develop de novo or with chronic inflammatory conditions
• Eradication of H. pylori can lead to resolution of MALT lymphoma
• MALT lymphoma involves infiltration by small, heterogenous lymphocytes
• Bone marrow involvement is uncommon in MALT
• The immunophenotype for MALT is nonspecific
• MALT overall has a good prognosis
• Lymphoplasmacytic lymphoma involves the proliferation of clonal B lymphocytes showing plasmocytic differentiation
• Lymphoplasmocytic lymphoma is marked by monoclonal gammopathy in serum or "Waldenstrom macroglobulinemia"
• Lymphoplasmacytic lymphoma is associated with a MYD88 mutation and has an indolent prognosis with a median survival of 5-10 years
• Hairy cell leukemia is uncommon and typically presents with massic splenomegaly and cytopenia/pancytopenia