Case Number : Case 1785 - 31 March - Dr Richard A Carr Posted By: Guest

Round your week off with a nice case from Dr Richard A Carr - for newbies and trainees first please.

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I thought of melanoacanthoma in this case

forgot to ask if the patient is an adultal although I would still think of melanoacanthoma

I have another impression, but waiting for newbies/trainees comments first...

I see hyperplasia of  keratinocytes without atypia and abundance of dendritic melanocytes. I think it is a melanoacanthoma, I am just not sure if it occurs in this location often. Am just waiting for Vincenzo's opinion!

Another thing: Will any of you attend melanoma course in Paris next month?

Epidermis shows psoriasiform hyperplasia due to proliferation of dendritic melanocytes interspersed among keratinocytes with pale-staining cytoplasm, except those keratinocytes of the basal layer and the adnexal epithelium. Pigmented clear cell acanthoma is my opinion.

Glad to see that Robledo has posted my exact opinion!!! I also thought of it as a pigmented clear cell acanthoma .. 

A bit late. I favour  pigmented clear cell acanthoma too...

yeah you guys are right

I was thinking of Pigmented Clear Cell Acanthoma, too. Typical alternating pattern of involved rete pegs and acanthotic uninvolved adnexal epidermis in fig 1. 

Good week to you all!

2 hours ago, msofopoulos said:

I see hyperplasia of  keratinocytes without atypia and abundance of dendritic melanocytes. I think it is a melanoacanthoma, I am just not sure if it occurs in this location often. Am just waiting for Vincenzo's opinion!

Another thing: Will any of you attend melanoma course in Paris next month?

 

I am a bit away from pathology until september due to a master so cannot go to Paris. However I will be attending ISDP meeting in september as we mentioned before It would be nice to meet you and the rest of colleagues

I will be (probably) attending the Glasgow meeting! It would be nice to meet you and the colleagues too!

Ok, we have a lesson today! I thougth melanoacanthoma, but now... pigment clear cell acanthoma. Congratulation, Robledo.

Would go for a pigmented clear cell acanthoma.

7 hours ago, msofopoulos said:

I see hyperplasia of  keratinocytes without atypia and abundance of dendritic melanocytes. I think it is a melanoacanthoma, I am just not sure if it occurs in this location often. Am just waiting for Vincenzo's opinion!

Another thing: Will any of you attend melanoma course in Paris next month?

 

You should get them to get me to record it  :-)

Thanks, Vincenzo (for delaying but contributing), Robledo et al for correcting my original diagnosis of melanoacanthoma. I just pulled the slides and agree pigmented clear cell acanthoma fits best. There are neutrophils in the epithelium as well, too much to just be explained  by the anatomic location / surface irritation I think. Surprised I did not appreciate this features at the time (photography often makes one scrutinise sections in greater detail than normal).

Well an even better case than I expected! 

Some regard clear cell acanthosis as a reaction pattern that can  be seen in other lesions and conditions with clear cell acanthoma being a recognisably distinct clinicopathological entity.