Expert guidance on the assessment of lymph nodes for Castleman Disease
We recommend following a three step process when assessing excisional lymph node biopsies for Castleman Disease-like changes. These steps are described below and additional guidance on each step can be accessed by clicking the begin button.
THREE STEP PROCESS
STEP 1:
Grading
There are five histopathological features which should be graded when assessing the presence of Castleman Disease-like changes:
- Regressed germinal centres
- Plasmacytosis
- FDC prominence
- Vascularity
- Hyperplastic germinal centres
Grade 2-3 regressed GCs OR grade 2-3 plasmacytosis must be present for a diagnosis of iMCD. The additional features are supportive of diagnosis and influence the process of histopathological subtyping.
STEP 2:
Exclusionary requirements
Once the presence of histopathological features has been confirmed, a diagnosis of iMCD requires the exclusion of diseases which can have similar presentations.
Some diseases can be excluded by pathology services and others must be excluded by clinical colleagues.
This section provides guidance on which conditions you can support the exclusion of and expert guidance on how to do this.
STEP 3:
Histopathological subtyping
The final step in the process is to assess which histopathological subtype applies.
There are three established histopathological subtypes of iMCD.
The clinical relevance of these subtypes remains somewhat unknown, but in certain scenarios the confirmation of subtype may help drive treatment decisions.
References
- Fajgenbaum DC, et al. Blood. 2017; 129(12): 1646-57.
Abbreviations
FDC, follicular dendritic cell; GC, germinal center; iMCD, idiopathic Multicentric Castleman Disease.
