International Soc of Bone & Soft Tissue Pathology

#PathQuiz 🔬🥩 #SoftTissuePath A) Atypical Lipomatous Tumor B) Myxoid Liposarcoma C) Nodular Fasciitis D) Pleomorphic Lipoma #Pathology #SoftTissuePath #DermPath

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

#PathQuiz 🔬🩸 #SoftTissuePath A) Pseudomyogenic hemangioendothelioma B) Epithelioid sarcoma C) Epithelioid hemangioendothelioma D) Angiomatoid fibrous histiocytoma #Pathology #SoftTissuePath #DermPath

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

30 yo woman with 6 cm soft tissue mass on upper arm. Answer ✅ youtu.be/yWWCZ-NLwOM Digital slide (best EVER!): kikoxp.com/posts/8192 #BSTpath #pathology #pathologists #pathTwitter #dermpath #dermatology #dermatologia #dermtwitter

Oxalate crystals #pathology #pulmpath

#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

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 bit.ly/4eu6WCD @SumantaDas_7

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.

Deep mass in NF1 patient. Diagnosis? More pics kikoxp.com/posts/17897 Answer ✅ youtube.com/watch?v=LBgsIa… Another example: kikoxp.com/posts/16855 #BSTpath #pathologists #pathology #pathTwitter

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

We had a fantastic ISBSTP session at USCAP last week, inc. dinner at Boudro's. A huge thanks to our officers, Julie Fanburg-Smith and Shi Wei, and the great lectures by Drs. Jessica Davis, Michael Michal, @JMcMahonG , and Rita Alaggio. @ISBSTP @CLEClinicLabs @TheUSCAP

Gene Siegal, M.D., Ph.D., a professor emeritus in the Division of Anatomic Pathology, was recently named an American Association for the Advancement of Science @aaas Fellow for 2025. Read more about this lifetime honor here: bit.ly/40UdkuO

60 M with 2 cm breast mass Answer ✅ youtu.be/eLmPGdjjAFg Digital slide: kikoxp.com/posts/4600 Immunostains: kikoxp.com/posts/4740 #pathology #pathologists #pathTwitter #dermpath #dermatology #dermatologia #dermtwitter #breastpath

#PathQuiz 🔬🦴 _______ rearrangement A) USP6 B) FN1 C) COL12A1 D) GRM1 #Pathology #SoftTissuePath #BonePath #MolecularPath Clue in caption 🧐 @IARCWHO

Face of elderly sun damaged patient. Diagnosis from one pic? Answer ✅ youtu.be/2lQbrjpFtDk?si… Digital slide & info: kikoxp.com/posts/18999 #BSTpath #pathology #pathologists #pathTwitter #dermpath #dermatology #dermatologia #dermtwitter

#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 🧐

Deep (Aggressive) Angiomyxoma 🔑•Young women, pelvis/perineum •Large, deep-seated mass (often >10 cm) •Locally infiltrative (despite “benign” cytology) •High recurrence rate, rare metastasis   🔬 Morphology •Hypocellular spindle–stellate cells and abundant myxoid stroma •Haphazard vessels: Thin-walled capillaries and thick-walled vessels (key clue) •Entrapment of fat, nerves, adnexa → very important •No atypia / mitosis / necrosis   🧪 IHC profile •Positive: Desmin, SMA, ER / PR ⭐ (very helpful clue), CD34 variable/focal •Negative: S100 , DOG1 , CD117   🧬 Molecular: Often HMGA2 rearrangement (12q15)   🔍 Differential diagnosis 1️⃣ Angiomyofibroblastoma •Superficial, small, well-circumscribed. Alternating hypercellular & hypocellular areas. •Plump stromal cells clustering around vessels. No infiltration/entrapment •Desmin+, ER+, but location + circumscription key   2️⃣ Cellular angiofibroma ✔️ Cellular + hyalinized vessels + CD34 strong ❌ Lacks diffuse myxoid stroma & infiltration   3️⃣ Myxoid neurofibroma ✔️ S100+ + wavy nuclei ❌ No desmin/ER pattern, no vessel spectrum   💎 Diagnostic pearls:   •Deep pelvic/perineal mass •Hypocellular myxoid lesion •Thick + thin vessels •Entrapment of fat/nerves •Desmin + ER/PR +   #Pathology #SoftTissueTumor #Dermpath #GynPath #MedTwitter #PathTwitter #Histopathology #TumorBoard #MedicalEducation

@KonstantinosLin #IDSP2026Denver Not every tumor with melanocytic differentiation is a nevus, melanocytoma, or melanoma. Clear cell sarcoma remains the prototype of a fusion-driven mesenchymal tumor with melanocytic differentiation

Our field advances because experienced pathologists take the time to guide those coming up behind them. Apply to serve as a mentor in the USCAP Mentoring Academy and invest in the future of our profession. uscap.org/mentoring-acad…