We would like also to thank all the residents who hosted the large number of candidates interested in @UPMCPath and had a major effect on the success of this year’s match @UPMCPathology

Proud to highlight the strong presence of @UPMC faculty, trainees and #cytologists at #ASC2025 in Saint Louis! 🎉 Thanks to the dedicated team advancing #cytopathology through research, education & innovation. @SamKhader @PathPro @ohorimd @cudajm @PancPathologist

Proud to highlight the strong presence of @UPMC faculty, trainees and #cytologists at #ASC2025 in Saint Louis! 🎉 Thanks to the dedicated team advancing #cytopathology through research, education & innovation. @SamKhader @PathPro @ohorimd @cudajm @PancPathologist

Answer: Myeloid Sarcoma with concurrent low level bone marrow involvement. Pathology reports from the orchiectomy specimens revealed testicular involvement by myeloid sarcoma. Thank you, @ShikhaPath and Dr. Aggarwal, for sharing such an interesting case! @dwu101

Additionally, peripheral blood (PB) and bone marrow (BM) evaluation was normal on CBC and PB flow. BM was histologically normal with negative cytogenetic studies, microarray analysis, FISH, and myeloid NGS. However, IHC studies identified rare cells (<1%) with NPM1 positivity.

Flow cytometry revealed an expanded myelomonocytic population positive for CD123, CD33, HLA-DR, CD56, CD64, CD36, CD13 and negative for CD34, CD117, CD16, CD11b, CD14 and TdT. NGS revealed NPM1 p.W288fs, FLT3 p.I836del and PTPN11 p.E76A mutations.

The cells showed irregular nuclear contours and frequent apoptotic bodies. IHC stains revealed the lesional cells to be positive for IRF8, CD68, CD33 and NPM1, and negative for CD34, CD117, MPO, glycophorin, E-cadherin, CD61, CD19, CD20, PAX5, CD3, and pankeratin.

Biopsy of one of the right chest/shoulder nodules was performed. On gross examination, the mass was rubbery to firm and measured 2.7 x 1.8 x 1.0 cm with the attached adipose tissue. Cut surface was fleshy, tan with small hemorrhagic areas.

CP Case of the Month: 61-year-old male with history of T2 DM, HTN, HLD, nephrolithiasis, basal cell carcinoma (s/p excision), and bilateral testicular masses (s/p recent bilateral orchiectomy at an outside hospital 2-3 months ago) presented with multiple chest wall masses.

🧫 Path pearls: – Marrow often hypercellular w/ myelomonocytic/monocytic differentiation – Multilineage dysplasia possible – “Cup-like” nuclei in blasts ☕ – Immunophenotype: usually CD34−, CD33+, CD117+, CD123+ – May mimic APML (CD34− / HLA-DR−)

NGS confirmed mutations in NPM1, FLT3, IDH2, NRAS, SRSF2 🧬 → final dx: AML with mutated NPM1. This is the most common molecular subtype of AML (~30% of adult cases).

The CD34− / HLA-DR− pattern suggested acute promyelocytic leukemia (APML). ⚠️ But PML::RARA FISH was negative. A positive NPM1 IHC stain raised suspicion for NPM1 mutation.

CP case of the month: A man in his 80s with unexplained anemia 📉. Presents w/ SOB + chest pressure. Labs: leukocytosis, anemia, thrombocytopenia + 30% circulating blasts 🩸 Bone marrow: 70–80% blasts by flow → +CD33, CD117, CD123; −CD34, HLA-DR Differential?

@UPMCPath invites all interested applicants to our last open house for the year! Learn why our residency is ranked among the top training program. Third UPMC Pathology Residency Program Virtual Open House Tuesday, September 16, 7-8:30PM EDT (Sign Up Link: https://t.co/800nEN3r1x

Answer: C) STAT6 ✅ Nuclear STAT6 staining reflects the NAB2::STAT6 fusion, highly sensitive & specific for SFT. CD34 is often lost in dedifferentiated areas, but STAT6 usually persists, making it the most reliable marker. 🧪 @HaleyCorbin7

SFTs are rare fibroblastic neoplasms, usually indolent, but can dedifferentiate → aggressive behavior. Which marker is most specific for SFT? A) CD34 B) BCL2 C) STAT6 D) Desmin

Molecular: NAB2::STAT6 fusion (pathognomonic for SFT) 🧬, +TERT & TP53 mutations, complex copy number changes. 👉 Final Dx: Dedifferentiated solitary fibrous tumor, high-grade

🔬spindle cell areas w/ patternless pattern & staghorn vessels 🌿(A) abrupt transition → round cell dedifferentiated component (B) (60 mitoses/10 HPF, 10% necrosis). IHC: +CD34 (C) (lost in round cell areas, D), +STAT6 (E,F), focal SMA/synaptophysin/SMMHC. Ki-67 ~30%. Diagnosis?

Elderly woman with a tender paraspinal mass. CT: enlarging, partially calcified nodule (2.4 cm in 2022 → 5.2 cm). Chest CT: lung mets 🫁

Honored to be named one of the 2025 #ASCP40UnderForty honorees! Proud to represent the power of digital pathology, AI, and innovation in patient care. 🗳 Vote to help me become a Top 5 honoree! 👉 https://t.co/izFNDcqPZy #PathTwitter #ASCP40Under40 @UPMCPathology

@UPMCPath invites all interested applicants to join our open houses! Learn why our residency is ranked among the top training programs in the country. Our Second Virtual Open House: Thursday, September 11, noon - 1:30PM EDT (Sign Up Link: https://t.co/wh9SUbNlrH