π§΅ 1/9
Elderly male. Metastatic colorectal cancer with liver mets. RAS wild-type β looks straightforward.
Then the molecular profile comes back: HER2 IHC 3 .
This changes the entire treatment plan. Here's why π
ALT colorectal adenocarcinoma with HER2 expression
ALT colorectal adenocarcinoma with HER2 expression
ALT colorectal adenocarcinoma with HER2 expression
8/9
Key detail on testing π¬
IHC 3 responds well. IHC 2 without amplification β almost no benefit.
Use HERACLES criteria, not breast cancer scoring. And when possible, test the metastatic tissue β not just the primary.
9/9
The takeaway:
π΅ HER2 3 rules out anti-EGFR therapy
π΅ Opens access to two approved targeted regimens
π΅ Age is not a reason to treat blind
Test it, it really matters.
#gipath#pathtwitter#pathology
π§΅ 1/6
A nodule on the face. Sent as a skin biopsy. No clinical history provided. Spoiler: this is NOT a primary skin tumor. π
#pathtwitter#dermpath#uropath#pathology
ALT H&E staining. Skin biopsy: intact epidermis and a dermal tumor composed of clear cells, separated by a prominent network of thin-walled vessels.
ALT H&E staining. Skin biopsy: intact epidermis and a dermal tumor composed of clear cells, separated by a prominent network of thin-walled vessels.
ALT H&E stain. High-power view showing tumor cells with abundant clear cytoplasm and small, round, uniform nuclei. Thin-walled vessels are visible between tumor cell nests.
ALT H&E stain. High-power view showing tumor cells with abundant clear cytoplasm and small, round, uniform nuclei. Thin-walled vessels are visible between tumor cell nests.
5/6
π Take-home points:
β Clear cells in skin = always rule out metastasis
β RCC loves to metastasize late and to unusual sites
β PAX8 CD10 CAIX = your best IHC friends here
6/6
Bottom line: clinical history is not just background noise β it is part of the diagnosis. Never forget that π
Have you ever seen a case like this? π
1/3 #GIpath#CritterOnTwitter Look what I found in this inflamed antral hyperplastic gastric polyp π€. At first glance, I thought that it is hallucinations or illusions due to end of the week fatigue π then I started to take images of every single one. So all are represented π
ADH in Radial Scar π«π¬
Occasionally, atypia can be spotted within sclerosing lesionsβhere, a monotonous epithelial proliferation partially filling ducts within a fibroelastotic, architecturally distorted background.
#PathX#PathTwitter#breastpath
π§΅ Not all breast carcinomas are created equal π§¬
Here's how p63 expression shifts as tumors progress toward a basal/stem-cell phenotypeπ
#pathtwitter#breastpath#pathology
ALT Illustrated diagram showing p63 expression across three breast tumor types. Tumor 1 (G1/G2 NST): uniformly blue cells, p63-negative. Tumor 2 (G3 NST): predominantly blue cells with scattered brown cells, p63-positive, triggered by TP53 mutation. Tumor 3 (Metaplastic carcinoma): predominantly brown cells, p63-strongly positive. An arrow along the bottom indicates increasing basal program activation, aggressiveness, and stem-cell phenotype from left to right.
π΅ G1/G2 NST β p63β
π€ G3 NST β p63 (e.g. TP53 mutation as a trigger)
π€π€ π€ Metaplastic carcinoma β p63
The more basal the program β the more aggressive the tumor. Metaplastic carcinoma is the extreme end of this spectrum.