Advances in Hematology / 2012 / Article / Tab 2

Review Article

Grey Zone Lymphomas: Lymphomas with Intermediate Features

Table 2

Common and distinguishing features of BL, DLBCL, and B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and BL (BCLu-DLBCL/BL).

BLDLBCLBCLu-DLBCL/BL

Common features
 AgeYoung children and less frequent young adultsLess frequent in children but frequent in adults of all age groupsMainly diagnosed in adults
 GenderMale predominanceNo real predominance
 LocalizationOften extranodal (jaw and iliac region)Nodal and extranodalOften extranodal (no predominant region) often widespread disease leukemic presentation is possible
 MorphologyFrequent mitotic figures and apoptosis often with starry sky patternFrequent mitotic figures and apoptosis may be presentFrequent mitotic figures and apoptosis often with starry sky pattern resembling BL
 ImmunophenotypeCD10, BCL-6 positive, BCL-2 negative“BL immunophenotype” (CD10, BCL-6 positive, BCL-2 negative) may be presentVariable depending on morphologic features (see text)
 Genetic and  molecular featuresTypical IG-MYC fusion, simple karyotypeTypical IG-MYC fusion may be presentOften non-IG-MYC fusion complex karyotype

Distinguishing features
 MorphologyMedium-sized blastic cells with basophilic cytoplasm, no inflammatory background, sometimes cohesive growth pattern
Small nucleoli at the periphery, mitotic rate always very high (Ki67 )
Pleomorphic large blastic tumor cells, often inflammatory infiltrate, mitotic rate variable
 Genetical and  molecular featuresTypical cMYC fusion with IG light or heavy chain locus, simple karyotype
More complex karyotypes possible (sign of progression)
Other types of cMYC fusions can be present (other than IG as a partner), complex karyotype possibleCombination of BCL2 and/or BCL6 breaks possible (so-called “double or triple hit lymphomas”)