Case Number : Case 2915 - 08 September 2021 Posted By: Uma Sundram

This looks like an old, dried-out slide.  There are lots of fissures in the dermis which I suspect are artefactual, and some tinctural changes in the connective tissue which may also be due to aging of the slide.  The third image shows a cluster of atypical, hyperchromatic cells, possibly endothelial.  Is this angiosarcoma, possibly Kaposi's?

Difficult. The second img shows microthrombosis.  The atypical cells could be pc. ?? IgM-related( Waldenstrom) DIC. 

The last photo shows plasma cells. Features in the background dermis are difficult to tell but I was thinking amyloidosis associated with plasma cell dyscrasia such as multiple myeloma. Vincenzo has a great point this can be Waldenstrom. May we have some stains please (PAS, congo red, kappa and lambda)?

14 hours ago, John Zhang said:

The last photo shows plasma cells. Features in the background dermis are difficult to tell but I was thinking amyloidosis associated with plasma cell dyscrasia such as multiple myeloma. Vincenzo has a great point this can be Waldenstrom. May we have some stains please (PAS, congo red, kappa and lambda)?

Oh yes. What seems to me microthrombs could be amyloid!!!

Nodular amyloidosis. Congo red is positive and the plasma cells are kappa light chain restricted.