Thanks Jonathan, that means a lot to me.

🙏 (Finally, the perfect use of that emoji)

Indeed. Biology is merciless to our strengths and weaknesses.

Dx: PD chordoma w/ SMARCB1 loss. I felt so bad I offered to see the patient to apologize but my ortho onc wouldn’t let me lol. Did CK on bx and sure enough, little histiocytoid fragments w/ TINs +. I was humbled, big time. It still haunts me yrs later as I put chordoma in the ddx when I shouldn’t

Knee replacement done. Low power. had melting wax look peripherally, w/sheets and large islands of histiocytoid cells with tt necrosis & TINs. CK, EMA +, S100 -, INI1 loss. I called ES. Sent to you guys. Judith emails me it’s brachyury + and my head is spinning.

Thanks for bringing up. One of my cases was in that paper. I failed twice. Pt was 60s F. Initially, was clinically portrayed as knee TGCT w/ bone erosion. Bx showed synovitis w/ heme, mixed inflam, foam cells and small bits of what looked like histiocytes a/w neuts. I called TGCT.

TTF1

#PathSky 84M with lung nodule, signed out as “adenocarcinoma, favor pulmonary origin”. There is supposed to be a bit of TTF1 expression, but it is subtle to say the least.

I was excited to add ‘modulated’ to my descriptors repertoire 😅

But what if you miss a cool looking neutrophil on slide 133? Can’t let that happen 😂

What a saga, I love it!

Very good to know, thank you.

Tricky one!

Okay then, let’s look closer. That material is odd. Spherical ones remind me of tyrosine crystals a bit. The intervening cells are giant cells closely apposed to material, and non descript fibro/myofibro type cells. I’m thinking about pseudogout. Not sure if crystal morph matches though.

I’m with you, my mistakes are vivid. Some will never be forgotten.

Calcifying aponeurotic fibroma, schwannoma, pmt? Any stains?

Excellent case! Never seen one with that pattern

3rd image made me want STAT6. Then I got instant gratification! Great case, thank you.

Kal-sp, favor KA. P53, p16, ki67?

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