International Soc of Bone & Soft Tissue Pathology

The ISBSTP is a non-profit organization founded in 2001 by a group of pathologists interested in collaboration, education, and sharing resources in #BSTpath

[Elizabeth Montgomery, MD @LizMontgomeryMD]

Extra-uterine endometrial stromal sarcoma has a knack for mimicking synovial sarcoma. The staghorn vessels and overlapping nuclei always send me down the wrong path at first but the collagen saves the day! Yay - Phew.

[USCAP @TheUSCAP]

VGLL3-rearranged Spindle Cell Rhabdomyoblastic Tumor: A Clinicopathologic and Molecular Genetic Study of 18 Cases with Consistently Indolent Behavior

✅ Just Accepted
📗 @ModernPathology

https://t.co/iCXSckrnEj

[Sanjay Mukhopadhyay @smlungpathguy]

@MaiElzieny @parthisandy 20.
Two fungal hyphae you might see in the lung are Aspergillus (green circle, more common) and Mucor (red circle, less conmon). Aspergillus has septa and branches at acute angles, Mucor has few or no septa and has more irregular shapes.

Not always easy to tell them apart!

[Janira Navarro @Janiranavarro]

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

[Jerad Gardner, MD @JMGardnerMD]

Soft tissue tumor pathology BASICS video: https://t.co/gsKiu0yyUE. My resident Iman Sarami, MD @ ImanSarami & I discuss 10 classic cases for you in this video. #BSTpath #pathologists #pathology #pathTwitter #dermpath #dermatology #dermatologia #dermtwitter #sarcoma

[Int Soc Dermpath @IntSocDermpath]

#Pathology #Histology #MedicalEducation #DermPath #Pathology #Dermatology #Intsocdermpath #MedEd

[Jerad Gardner, MD @JMGardnerMD]

Deep thigh mass. Can you make diagnosis from one pic, or #TooCloseToDiagnose?
Answer ✅ https://t.co/IfEvVaUEsD
If you could only get ONE immunostain, what would it be?👉https://t.co/io7WsRFKdA
#pathology #pathologists #pathTwitter #dermpath #dermatology #dermtwitter #BSTpath

[Felipe Templo Jr. ,MD, MBA 🕊 @thejourneymate]

Algorithm of Immunohistochemistry in Soft Tissue Sarcomas 🔬

(c): Dr Rakesh Kumar

[Janira Navarro @Janiranavarro]

*Dogma-defying soft tissue tumors*

Not all EWSR1-WT1 fusion tumors are desmoplastic small round cell tumors (DSRCT)

There are unusual EWSR1-WT1 fusion-positive tumors with glomoid/myoid morphology, lacking desmoplasia, showing desmin/SMA positivity on IHC, and a favorable clinical prognosis.

Dr. Warmke #USCAP2026 #pathology #PathX #PathTwitter

[Charlie Herndon @DrCycloPath]

#PathQuiz 🔬🥩 #SoftTissuePath

A) Atypical Lipomatous Tumor
B) Myxoid Liposarcoma
C) Nodular Fasciitis
D) Pleomorphic Lipoma

#Pathology #SoftTissuePath #DermPath

[Meredith Herman, DO @MeredithKHerman]

This was a tricky diagnosis:

Intravenous leiomyomatosis is a benign yet odd intravascularly proliferative lesion characterized by worm-like growth through pelvic veins in the setting of a uterine leiomyoma.
#gynpath #PathX

[Charlie Herndon @DrCycloPath]

#PathQuiz 🔬🩸 #SoftTissuePath

A) Pseudomyogenic hemangioendothelioma
B) Epithelioid sarcoma
C) Epithelioid hemangioendothelioma
D) Angiomatoid fibrous histiocytoma

#Pathology #SoftTissuePath #DermPath

[Dr. Arkadip MD @pathognosis22]

Benign bone disease #NEETPG #NEETSS #INISS #INICET #BST #Bone_pathology #pathology #pathognosis

[Jerad Gardner, MD @JMGardnerMD]

30 yo woman with 6 cm soft tissue mass on upper arm.
Answer ✅ https://t.co/IJvbLbbSaX
Digital slide (best EVER!): https://t.co/dSECc8b35w
#BSTpath #pathology #pathologists #pathTwitter #dermpath #dermatology #dermatologia #dermtwitter

[Sanjay Mukhopadhyay @smlungpathguy]

Oxalate crystals

#pathology #pulmpath

[Charlie Herndon @DrCycloPath]

#PathQuiz 🔬🔬 #GUPath

A) Rhabdomyosarcoma
B) Diffuse Large B-cell Lymphoma
C) Clear Cell Sarcoma of the Kidney
D) Desmoplastic Small Round Cell Tumor

#Pathology #GUPath

[JClinPath_BMJ @JClinPath_BMJ]

Superficial CD34 positive fibroblastic tumour - An novel soft tissue tumour with indolent behaviour but alarming histology.

Learn more about morphologic subtypes, defining translocations (any guesses?), differential diagnoses and more from this systematic review of 190 cases out now in the JCP https://t.co/ELuSYv8mFS

@SumantaDas_7

[Italian Sarcoma Group @ItaSarcomaGroup]

Great insights from Prof. Dei Tos on the upcoming updates in the World Health Organization 2026 #sarcoma classification. Emerging entities are reshaping our understanding of soft tissue tumors, highlighting the growing impact of molecular pathology in diagnosis and treatment.

[Jerad Gardner, MD @JMGardnerMD]

Deep mass in NF1 patient. Diagnosis?
More pics https://t.co/Wi6GKxdv9S
Answer ✅ https://t.co/2xkUXXxxHA
Another example: https://t.co/hhWikyV6hl
#BSTpath #pathologists #pathology #pathTwitter

[Isidro Machado MDPhD @MachadoIsidrin]

We are pleased to share the upcoming May SEAP/IMPERAS/GEIS Sarcoma session. We hope to see you there.😊😉