Case Number : Case 1907 - 19 Sept - Dr Richard Carr Posted By: Guest

Beautiful :-)

43 minutes ago, Dr. Mona Abdel Halim said:

Beautiful :-)

 

Agree, pictures are of extremely high quality

Lovely example indeed!

Keratoacanthoma! Very nice photos

Thanks all for the kind comments. This is actually a "textbook" case of keratoacanthoma (KA) and a type you rarely see in practice!  In fact the rather pushing borders, lacking elastic entrapment, lacking striking cellular pleomorphism is actually more in favour of KA-like reaction in SEBK, inverted follicular keratosis and follicular squamous cell carcinoma (infundibular-tricholemmal type). Also KA are usually much larger at diagnosis and rarely fall short of the sweat gland coils as in this case. In my routine practice early to well developed proliferative KA are highly infiltrative and show much more florid cellular proliferation and cellular atypia. Features here that are typical of KA are the nice symmetry, abrupt transition/maturation in the centre of all islands, lack spontaneous acantholysis and lack of follicular mucin. I suspect this is the sort of KA that even those who rarely make the diagnosis will probably accept the diagnosis but one I don't see very often (so much so that it's taken me a while to find this one). More commonly a small lesion with pushing borders resembling KA is another diagnosis including KA-like reaction in inflamed SEBK, inverted follicular keratosis and well differentiated follicular (infundibular-tricholemmal type) squamous cell carcinoma.