Eugenia Ortega Pinto

Pathology lover 🔬

[Janira Navarro @Janiranavarro]

MUC4 is not specific

The list of neoplasms with MUC4 expression is continuously expanding and includes low-grade fibromyxoid sarcoma, synovial sarcoma, myoepithelioma, MUC4-positive fibroblastoma, alveolar rhabdomyosarcoma, FET::CREB rearranged mesenchymal tumors, and ossifying fibromyxoid tumor

Case below: Ossifying fibromyxoid tumor (pic 1) with MUC4 expression (pic 2)

Dr. Fritchie Comprehensive and Immersive Soft Tissue Pathology Course 2026 #pathology #PathX #PathTwitter

[Eugenia Ortega Pinto @Euortegap]

@pokepatologo Un martes normal

[Janira Navarro @Janiranavarro]

Interesting variants of mucoepidermoid carcinoma. Part 2

- They can be entirely negative for squamous markers (p40/p63)

This appears to happen in lung mucoepidermoid carcinomas in young patients with classic morphology and IHC completely negative for p40/p63

Dr. Bishop #USCAP2026 #pathology #PathX #PathTwitter

[Janira Navarro @Janiranavarro]

What if you have a lesion that looks like an NIFTP but is at the surgical margin?

If the positive margin is focal, call it:
- NIFTP, focally present at margin
and add a comment (pic 2)

If the positive margin is extensive, it is recommended to call it:
- Follicular neoplasm, present at margin
and add a comment (pic 3)

Dr. Nishino - 2025 Diagnostic Pathology Update #USCAP #pathology #PathX

[Elizabeth Montgomery, MD @LizMontgomeryMD]

Another spectacular EBV-associated gastric carcinoma (gastric carcinoma with lymphoid stroma). This example has overt gland formation and more sheet-like areas.

[Rajal B Shah @rajalbshah]

Attention Pathologists: Proud to present unified practice recommendations on Intraductal Carcinoma of the Prostate! No more confusion or contradictory recommendations between 2 leading societies! Download your free copy https://t.co/1ayogQ3VQy

[Hisham Alshuaibi @Hashimoto__0]

Ectomesenchymal Chondromyxoid Tumor

Synonyms: Oral myoepithelioma of soft tissue origin; reticulated myxoid tumor of the 👅; myoepithelioma of the 👅

Benign mesenchymal neoplasm of unknown histogenesis characterized by spindle-polygonal cells within myxoid-collagenous stroma & usually harboring RREB1-MRTFB gene fusion.
• Initially presumed to originate from uncommitted ectomesenchymal cell derived from the neural crest or myoepithelial cell tumor of either minor salivary gland/soft tissue origin.
• Recently, based on IHC & molecular genetics, including recurrent RRFB1-MRTFB fusion, smooth muscle & skeletal muscle differentiation, in addition to neuronal development suggested, although the exact origin remains uncertain

Clinical
• Uncommon
• No sex predilection; wide age range; median: 32y
• Asymptomatic, slow-growing, painless, submucosal nodular lesion of anterior dorsal 👅
• Pathogenesis:
○ ~90% of tumors: RREB1 to MRTFB (formerly MKL2):
‐ Fusion product is not disease specific & has been reported in other tumors: Biphenotypic sinonasal sarcoma, mediastinal mesenchymal neoplasms & “biphenotypic” oropharyngeal sarcoma.
‐ A minority of cases may have alternate molecular drivers, including EWSR1

• Histochemistry:
○ Tumor cells:
‐ Mucicarmine, PAS with & without diastase (-)
○ Extracellular matrix:
‐ Alcian blue (pH 0.4 & 2.5) (+)
‐ Mucicarmine faintly (+)
• IHC:
○ Consistently GFAP(+)
○ Weak &/or focal (+)ity for S100, pancytokeratin, EMA, p63, SOX10, desmin & SMA:
‐ Rarely myogenin(+)

#brucewenig

[Janira Navarro @Janiranavarro]

Practical approach to signing out GU pathology cases-Dr.Hirsch

Low grade, low volume carcinoma: Active surveillance
Intermediate grade, increased volume: Radical prostatectomy (RP), radiation + androgen deprivation therapy (ADT)
High grade, variable volume: RP, Radiation +ADT, NA therapy + RP
Any Gleason pattern 5: Prolonged hormonal therapy

#USCAP25 #PathX #pathology

[Everyday_Pathology @Pathology_Xever]

Cytopathology mini-courses free: study online here https://t.co/I4YOXCtuDz

[Varsha Manucha, MD @VarshaManuchaMD]

Pulmonary Histoplasmosis

BAL showing macrophages with intracytoplasmic yeast like forms.
PAP stain, ThinPrep.

#Cytology #Bugs

[Mateen Hussain @MateenH79781868]

So I start my morning today with these guys....

[Modern Pathology @ModernPathology]

Once in a while gastrointestinal stromal tumors (GISTs) spread to bone! Learn about GISTs in less common primary sites:
Gastrointestinal stromal tumors (GISTs) arising in uncommon locations: clinicopathologic features and risk assessment of esophageal, colonic, and appendiceal GISTs. Mod Pathol. 2022 Apr;35(4):554-563. PMID: 34702994.

[Human Pathology @Human_Pathology]

New in #HumPathol: Atypical Intraductal Proliferation (AIP) of the Prostate: Findings in Repeat Biopsy or Radical Prostatectomy in Patients who Met Pathologic Criteria for Active Surveillance. https://t.co/V6F1Vg5IWJ #pathology #PathTwitter #PathX #GUpath

[Ting Zhao, MD @TingZhaoPathdoc]

@MGBpathology @MGHPathology 💡🚨Check out our new publication:
Diagnostic Challenges in Identifying Concurrent Myeloid Sarcoma and High-Grade Prostatic Adenocarcinoma Within the Prostate
#GUpath #Hemepath
https://t.co/XsxnrHGBaR
@IJSPjournal @judith_ferry @KMCornejoMD @MGBpathology @MGHPathology

[Quique Revilla @Quique_rs]

Anterior mediastinal mass. Touch print of the core needle biopsy (CNB).

Diagnosis: Primary mediastinal large B-cell lymphoma (PMBCL).

#hemepath #cytopath

[Megan Smith @megothelioma]

Continuing the placental microorganism theme from last week, here's a case of placental listeriosis. The inset shows the gram positive rods that cause this patchy necrosis and exudative inflammation.

#pathtwitter #pathx #pathology #placentapath

[Raza Hoda, MD @RazaHoda]

Case of CIC-Rearranged Sarcoma of Breast 🔬

DUX4 immunohistochemistry can be used to identify CIC::DUX4 fusion in CIC-rearranged sarcomas, distinguishing this lesion from other round cell sarcomas and malignant mimics in the breast.

#PathX #PathTwitter #breastpath

[Rui Caetano Oliveira @Caetano_Pathol]

meeting an "old friend" - classic myoepithelioma!

[Ziad El-Zaatari @ziad_zaatari]

🔬 Tubules Galore! ⭕️⏺️ 🍩 ~ Tubular Adenoma of the Breast ~ #BreastPath #Pathology #PathArt

[Charlie Herndon @DrCycloPath]

Baby with a dome-shaped papule, diagnosis?
A) Langerhans cell histiocytosis
B) Solitary reticulohistiocytoma
C) Dermatofibroma
D) Juvenile xanthogranuloma
#DermPath #PathTwitter #Pathology #PediPath