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Richard Carr

Richard Carr

@racarr51.bsky.social

77 followers 50 following 180 posts

Dermatopathologist, Warwick Hospital UK. Interested in all dermatopathology esp. keratocanthoma (KA) & follicular SCC-KA-like. Personal interests: Golf, cider making, dogs - especially fostering guide dogs. Family = No1.

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Richard Carr @racarr51.bsky.social · Jan 14

www.sciencedirect.com/science/arti...
Link to the paper that should help everyone diagnose keratoacanthoma with greater confidence.

Richard Carr @racarr51.bsky.social · 1d

RAC9300: IHC as requested @rishiagrawal.bsky.social

Richard Carr @racarr51.bsky.social · 1d

Posting p16 & p53

Richard Carr @racarr51.bsky.social · 3d

Yes reactive (mosaic for p16, peripheral graded or wild type matching Ki67 distribution in lesions were basal / germinative cells a dominant). Some benign lesions have >proliferation c/w p53 expression. I believe this is a case in point.

Richard Carr @racarr51.bsky.social · 3d

RAC9306. EVG & Discussion. I thought this was a mitotic sebaceoma / sebaceous adenoma. MSH6 & PMS2 requested. So far been sceptical about clear-cut Seb Ca & MTS. See a lot mitotically active lesions erroneously called carcinoma.

Richard Carr @racarr51.bsky.social · 3d

RAC9306: IHC Montages, EVG & Comment Summary to follow

Richard Carr @racarr51.bsky.social · 3d

4me no overtly worrying features for malignancy. Yes no applique. Sebceomas can by highly mitotic (like pilomatrixoma). Benign adnexal lesions are often patchy weak mosaic (in my studies p16 tends to be much higher in Seb Ca). Additional IHC/EVG/BerEP4/EMA & comments posted.

Richard Carr @racarr51.bsky.social · 3d

RAC9300. Lower powers. @rishiagrawal.bsky.social #dermpath

Richard Carr @racarr51.bsky.social · 3d

RAC9300. F80 ish. Neck. ?SK ?AK

Richard Carr @racarr51.bsky.social · 3d

RAC9306: IHC here p16, p53, Ki67 @rishiagrawal.bsky.social These are representative.

Richard Carr @racarr51.bsky.social · 4d

RAC9306. M80s. Nose. SCC. #dermpath @rishiagrawal.bsky.social

Richard Carr @racarr51.bsky.social · 11d

Great to be in Cape Town. Wayne Grayson introducing the XLIV symposium of the ISDP = International Society of Dermatopathology.

Richard Carr @racarr51.bsky.social · 14d

👍 Broekaert...Kazakov. Squared-Off Nuclei and "Appliqué" Pattern as a Histopathological Clue to Periocular Sebaceous Carcinoma: A Clinicopathological Study of 50 Neoplasms From 46 Patients. Am J Dermatopathol. 2017 Apr;39(4):275-278. PMID: 28323778.
Applique is characteristic but not specific IMO.

Richard Carr @racarr51.bsky.social · 14d

Yes. Read discussions with @rishiagrawal.bsky.social For me a reactive PATTERN rather than a single entity and not a neoplasm. Relatively common and usually overlying bony prominences. I report at least one or two a year.

Richard Carr @racarr51.bsky.social · 14d

I often do EVG in such cases if I think it will affect management. Completely circumscript borders with no entrapment we regard as supporting in situ and more likely to consider "watchful waiting".

Richard Carr @racarr51.bsky.social · 14d

Yes FSCC. mainly in situ. In UK pT1 low risk are not followed up unless margins are close. I think I also favoured focal invasion. Margin was positive but I may have said "watchfull waiting may suffice". I'll check on that.

Richard Carr @racarr51.bsky.social · 21d

This lesion lacks neutrophil microabscesses and more importantly no signs of regression. With IHC highly aberrant null/weak only p53 FSCC-KA-LIKE is favoured.

Richard Carr @racarr51.bsky.social · 21d

Agreed. Mosaic p16 but highly aberrant null +/- weak only p53. Favours FSCC-KA-like.

Richard Carr @racarr51.bsky.social · 22d

RAC9302: What you need to asses such lesions. p16 & p53 - you should be able to work out which is which.

Richard Carr @racarr51.bsky.social · 22d

There is certainly a little mucin in the stroma. The edges of the keratinocytes have a hazy blue appearance but not convincing mucin pools. I'll post IHC now.

Richard Carr @racarr51.bsky.social · 24d

RAC9302 M80s Presternum. ?SCC #Dermpath @rishiagrawal.bsky.social

Richard Carr @racarr51.bsky.social · 26d

This was an SCC arising in actinic keratosis (4 more images here). There was tumour in a small muscular vessel in the deep dermis I interpreted as a vein. It's uncommon but can happen in SCC as well as otherwise typical KA and even in BCC. I find most SCC are de novo or follicular type.

Richard Carr @racarr51.bsky.social · 27d

RAC9299 F70s. Mid Upper Chest. #Dermpath @rishiagrawal.bsky.social

Richard Carr @racarr51.bsky.social · 27d

Still waiting comment #NeverACyst

Richard Carr @racarr51.bsky.social · Aug 22

RAC9222 M90s. Scalp ?BCC but on excision looks like epidermal cyst. #NeverACyst #Dermpath not for @rishiagrawal.bsky.social (he's seen it)

Richard Carr @racarr51.bsky.social · Sep 30

Sounds like granular cell EFH.

Richard Carr @racarr51.bsky.social · Sep 29

Agree null p16 (HIGHLY aberrant) & aberrant strong basal/suprabasal p53 (suggest a mutation ?dominant). Don't think we have option but to call it SCC (well diff, follicular infundibular-cystic). Anatomic location = v uncommon.