Thread by @SibaElHussein

The many faces of plasma cell neoplasm, diagnostic challenges of the great imitator in #hemepath ➡️bit.ly/3B3jMC1 with @ljmedeirosMD & @ShiminHuMDPhD #mmsm #lymsm #pathtwitter #leusm

1) The small cell variant (mimicking B-cell lymphoma, particularly mantle cell lymphoma➡️CyclinD1 positive) #hemepath #pathtwitter

2) Cleaved cell variant (mimicking follicular lymphoma) #hemepath #pathtwitter

3) Monocytoid variant (mimicking acute leukemia with monocytic differentiation) #hemepath #pathtwitter

4) Erythroid variant (mimicking pure erythroid leukemia) #hemepath #pathtwitter

5) Megakaryocytoid variant #hemepath #pathtwitter

6) Blastoid variant (mimicking AML) #hemepath #pathtwitter

7) Crystal storing histiocytoisis-like variant #hemepath #pathtwitter

8) Signet ring cell-like variant #hemepath #pathtwitter

9) Oncocytic variant #hemepath #pathtwitter

10) Lobular carcinoma-like variant #hemepath #pathtwitter

11) Pseudoalveolar variant #hemepath #pathtwitter

12) Aberrant cytokeratin expression

And many other unusual morphologic and immunophenotypic presentations here ➡️bit.ly/3B3jMC1

Take home message: If things are not adding up (clinical vs pathology findings), throwing in a CD138 stain will sometimes solve the puzzle