New entities in soft tissue pathology
***FET-CREB fusion sarcomas***
Variable histology with epithelioid/round cells showing an odd combination of multiple aberrant markers (CK, EMA, MUC4, ALK, CD30, synapto , etc.) is valuable for screening FET-CREB sarcomas
Half of cases are intra-abdominal
Wide age range
Highly aggressive
Will be included in the upcoming BST WHO book
FET-CREB is an umbrella term for fusions between FET genes (mainly EWSR1, sometimes FUS) and CREB family transcription factors (CREB1, ATF1, or CREM)
Pitfall: Angiomatoid fibrohistiocytoma (AFH) and FET-CREB sarcomas have a similar genotype, but morphology differs and, most importantly, AFH mortality is >1% versus >50% in FET-CREB sarcomas
Dr. Agaimy #USCAP2026 #pathology #PathX #PathTwitter
A 40-year-old male presents with a painless, slow-growing subcutaneous nodule on his leg
A) Myofibroblastoma
B) Glomus Tumor
C) Angioleiomyoma
D) Myopericytoma
#PathQuiz 🔬🧬 #SoftTissuePath
A 30-year-old female presents with a slowly enlarging, painless mass in the deep soft tissue of her abdominal wall.
A) Nodular Fasciitis
B) Solitary Fibrous Tumor
C) Low-grade Myofibroblastic Sarcoma
D) Desmoid Fibromatosis
#PathQuiz 🔬🧬 #SoftTissuePath
Happy to see our @Pathoutlines article on PATZ1-rearranged sarcoma published 👇🏼
https://t.co/uziryeRBEN
3 things to remember about PATZ1-rearranged sarcoma:
💎Pseudoalveolar/(micro)cystic change->Swiss 🧀-like appearance
💎Hyalinized blood vessels
💎Rhabdomyoblastic differentiation often seen -- skeletal muscle marker expression tends to be accentuated around the pseudoalveolar spaces
Check out our article online (link above) 😊
#PathTwitter #BSTPath
An 80-year-old female presents with a slow-growing, asymptomatic mass in the subscapular region
A) Desmoid Fibromatosis
B) Nodular Fasciitis
C) Low-grade Fibromyxoid Sarcoma
D) Elastofibroma
#PathQuiz 🔬🧬 #SoftTissuePath
Rosai-Dorfman disease in skin -somebody please call the police - the emperipolice! An S100 protein stain highlights the nuclei (arrow) and cytoplasm of abnormal histiocytes but not the engulfed inflammatory cells in the cytoplasm (emperipolesis - engulfment without destruction).
#PathQuiz 🔬
A 30-year-old presents with abdominal pain and a 5 cm multinodular mass centered in the gastric muscularis propria.
A) GIST
B) Plexiform fibromyxoma
C) Gastroblastoma
D) Synovial sarcoma
#Pathology#GIPath@IARCWHO
Clue in caption 🧐
Posterior fossa 4th ventricular brain mass in a young patient, what molecular alterations are likely detected in this lesion? 🤔
#pedipath#neuropath#pathology
What's the diagnosis of this spinal tumor? If you need to consult your Multidisciplinary Precision Evaluation team, go right ahead.😉 #pathology#neuropath#PathTwitter
Lichen nitidus. #dermatology: many tiny flat topped papules. #pathology: each papule is a small collection of histiocytes, lymphocytes, +/- giant cells falling dermal papillae being clutched by rete ridges (“ball in claw” pattern). #dermpath
Another frightful feature 🧛♂️ haunting pathologists 😱 this spooky season 🎃
Case of Microglandular Adenosis 👻🔬
Small round glands with bright eosinophilic secretions🩸infiltrating fat without myoepithelial cells that mimics invasion. 🧟♂️
#PathX#PathTwitter#breastpath