Case Number : Case 2521 - 05 March 2020 Posted By: Saleem Taibjee

Last two pictures make me thjnk of Blastic Plasmocytoid Dendritic Cell Lymphoma. CD56? CD4? CD 123?

ulcers, proptosis and dense infiltrate of atypical blast  like cells, some what a grenz zone

peripheral smear is needed urgently and IHC on the skin nodules to rule out leukemia/lymphoma/ BPDCN

1 hour ago, Krishnakumar subramanian said:

ulcers, proptosis and dense infiltrate of atypical blast  like cells, some what a grenz zone

peripheral smear is needed urgently and IHC on the skin nodules to rule out leukemia/lymphoma/ BPDCN

Agree!

Yes, complete IHC work up to verify leukemic/lymphoproliferative disorders

On 05/03/2020 at 14:41, Krishnakumar subramanian said:

ulcers, proptosis and dense infiltrate of atypical blast  like cells, some what a grenz zone

peripheral smear is needed urgently and IHC on the skin nodules to rule out leukemia/lymphoma/ BPDCN

Agree.

sir what is the final diagnosis

Lymphoproliferative disorder. IHC is needed

This was a recent case of extranodal NK/T cell lymphoma, nasal type. I think this is a truly rare skin presentation, only the second case I have personally encountered. There are a few learning points:

1. Proptosis is a recognised presentation (extra-nasal site of predilection) which I discovered after reviewing the literature.

2. In the images I tried to highlight the pseudoepitheliomatous hyperplasia. I was interested to discover that in the excellent review of pseudoepitheliomatous hyperplasia by Zayour and Lazova in Am J Dermpathol 2011;33:112-126, which includes a comprehensive table of possible causes, this particular lymphoma is listed as the first under lymphoproliferative causes (even above anaplastic large cell lymphoma). I had seemed to have previously missed this feature as a good diagnostic clue to this particular lymphoma when presenting in the skin.

3. Angiocentricity/angioinvasion is not present in all cases, and was not a conspicuous feature in this case.

4. The case also highlights the need for a good/efficient (cost-effective) screening immunohistochemistry panel for patients presenting with ulcerative nodules and a short history, when of course mycosis fungoides becomes less likely. An excellent review article is Gru AA, et al. A systematic approach to the cutaneous lymphoid infiltrates. Archives of Pathology & Laboratory Medicine 2019; 143:958-979 in which the authors present a nice algorithm. I might suggest the following: CD56 (which really assisted me in this case), cytotoxic markers (e.g. TIA-1, Granzyme or Perforin), CD2, EBER, CD30, CD123, beta-F1 as a good starting point. This will avoid breaking the bank, but provide a good starting point for working through the differential diagnosis.

In this case CD56 and EBER are shown below, also positive was granzyme, TIA-1. CD3 was also positive (membranous), reflecting that some cases also express T-cell markers, although PCR was not performed in our case.

BW

Saleem

Great case! Thanks!