Case Number : Case 2886 - 29 July 2021 Posted By: Saleem Taibjee

This needs clinical correlation..Focal interface changes with high up dyskeratotic kcs and hint of neutrophilic dermal infiltrate in a child.. To start the discussion what about Still's disease?

A parakeratotic thin layer fits with an acute but basically parakeratotic disorder.  There is an interface dyskeratotic but also vacuolar lesion pattern. So it’s a Mucha Haberman for me. 

Beautiful case. Saw those vacuolar interface changes with keratinocytes dyskeratosis and focal "lymphocytes satellitosis". dermal pigment incontinence is noted. Clearly need clinical history, but I guess this kid may have had stem cell transplant and now have acute GVHD. waiting for your answer, Saleem.  Always enjoy your cases. 

Just a a few participant responses on this case, but nonetheless very interesting to see these responses which illustrate the wide histological differential diagnosis and challenging nature of such cases, and need for clinicopathological correlation ....

Well done, Henry. Yes this was indeed a recent case of GVHD which developed approximately 3 weeks after stem cell transplantation for leukaemia. Of course, the difficulty in such cases is that the clinical differential diagnosis often lies between GVHD and drug reaction, and the histology often cannot allow for confident distinction, although we might look for eosinophils, etc. But I put this case in because I thought it was indeed a nice example of satellite cell necrosis (as Henry also spotted, illustrated in the final 2 images above) which as we know can be a feature/clue to GVHD.

BW

Saleem