Woo Cheal Cho, MD

Subcutaneous Panniculitis-Like T-Cell Lymphoma With Increased γδ T Cells: A Potential Diagnostic Pitfall - PubMed Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare primary cutaneous T-cell lymphoma with adipotropism characterized by infiltration of CD8 + T cells exhibiting a cytotoxic and αβ phenotype. Although SPTCL is typically indolent, distinguishing it from more aggressive cutaneous lymphoma …

A striking increase in gamma/delta T-cells in subcutaneous panniculitis-like T-cell lymphoma (SPTCL) can be a major diagnostic pitfall. Recognizing this pitfall is crucial to avoid misclassification. A must-read for fellow #dermpath and #hemepath enthusiasts! 😆🔬

pubmed.ncbi.nlm.nih.gov/40532089/

#USCAP2026 in TX is just around the corner! 😆🔬🤠

Excited to connect with incredible pathologists and #pathology trainees and to see the latest studies in #dermpath.

As a bonus, here’s a special stain that turned into a bit of pareidolia. 👀
What do you see in it? #MDACCPath

Atypical Spitz Tumor/Spitz Melanocytoma Revealing a VIM::NTRK3 Gene Fusion: Clinicopathological Correlation of a Unique Molecular Finding - PubMed Spitz tumors are a heterogeneous group of melanocytic neoplasms ranging from benign Spitz nevi to malignant Spitz melanomas, with atypical Spitz tumors/Spitz melanocytoma occupying an intermediate position within this biological spectrum. A hallmark of all these lesions is the presence of specific g …

Bit late in sharing this, but excited nonetheless! Here’s a report featuring another novel fusion, VIM::NTRK3, in a Spitz neoplasm.

An educational case for anyone into #dermpath & #molepath combos! 😄🔬🧬

pubmed.ncbi.nlm.nih.gov/40591913/

⏳ Only 17 days until #USCAP2026! What are you most excited for this year?

🔬 New research
🤝 Connecting with colleagues
📚 Learning from experts
🌎 Being part of the global pathology community

#pathology #PathSky #MedSky

NSD3::FGFR1 : A Novel Gene Fusion First to Be Described in Merkel Cell Carcinoma - PubMed Merkel cell carcinomas (MCCs) exhibit diverse molecular profiles, often categorized by their association with Merkel cell polyoma virus (MCPyV). MCPyV-associated MCCs typically display a low tumor mutational burden (TMB), lacking both somatic mutations and ultraviolet signature. By contrast, MCPyV-n …

When was the last time you encountered a gene fusion in Merkel cell carcinoma?

Here is the first documented case of MCPyV-positive MCC harboring a novel NSD3::FGFR1 gene fusion. Check it out if you love #dermpath and #molepath! 😆🔬🧬

#MDACCPath

pubmed.ncbi.nlm.nih.gov/40036479/

<em>JEADV Clinical Practice</em> | Clinical Dermatology and Venereology Journal | Wiley Online Library Click on the article title to read more.

Endocrine mucin-producing sweat gland carcinomas presenting as blue-gray papules, as reported by Likki et al. 😆🔬

#dermpath #dermatology #pathology #MDACCPath

onlinelibrary.wiley.com/doi/10.1002/...

Diffuse cutaneous ALK-immunoreactive histiocytosis with MEF2C::FLT3 fusion Anaplastic lymphoma kinase (ALK)-positive histiocytosis was described in 2008 as a rare histiocytic proliferation in early infancy, accompanied by hepatosplenomegaly and hematological abnormalities.1 ...

www.jaadcasereports.org/article/S235...

Diffuse cutaneous ALK-immunoreactive histiocytosis with MEF2C::FLT3 fusion - PubMed Diffuse cutaneous ALK-immunoreactive histiocytosis with MEF2C::FLT3 fusion

We share our experience with an unusual, diffuse cutaneous ALK-immunoreactive histiocytosis with a MEF2C::FLT3 fusion. Check it out if you love the #dermpath and #molepath combination. 😆🔬🧬

#MDACCPath

pubmed.ncbi.nlm.nih.gov/41211348/

🚨 Hot off the press! The most comprehensive open-access review of TRPS1 and its applications in #dermpath is now available. Everything you need to know, based on our 4+ years of experience, is in one place. Check it out! 😆🔬

www.jpatholtm.org/journal/view...

#MDACCPath #IHCPath #TRPS1

The evolving role of TRPS1 in dermatopathology: insights from the past 4 years - PubMed Over the past 4 years, trichorhinophalangeal syndrome type 1 (TRPS1) has rapidly gained attention among practicing pathologists, with numerous studies emerging that both support and question its diagnostic utility. Initially regarded as a highly specific marker for tumors of mammary origin, TRPS1 is …

Lastly, when in doubt, read this most comprehensive review on TRPS1 #IHCPath, which incorporates our extensive experience with this marker over the past 4–5 years in #dermpath. Free access! 😆🔬

#MDACCPath

pubmed.ncbi.nlm.nih.gov/41605620/

TRPS1 expression in primary and secondary extramammary Paget diseases: An immunohistochemical analysis of 93 cases - PubMed Extramammary Paget disease (EMPD) predominantly manifests de novo as primary EMPD, with less than 30 % of cases associated with underlying internal malignancy (secondary EMPD). Differentiating primary from secondary EMPDs based solely on histopathology poses challenges, often necessitating supplemen …

And this was by far the largest study on this topic, including more than 90 cases of EMPD, and it was the first to demonstrate that primary perianal EMPDs lack TRPS1 expression, an important diagnostic pitfall. 😆🔬

#MDACCPath #dermpath

pubmed.ncbi.nlm.nih.gov/38000676/

Immunohistochemical expression of TRPS1 in mammary Paget disease, extramammary Paget disease, and their close histopathologic mimics - PubMed TRPS1 may be useful to distinguish MPDs/EMPDs from MISs, but its utility is limited in distinguishing them from other pagetoid intraepidermal neoplasms such as SCCISs.

This was the very first study on this topic by #MDACCPath #dermpath published in 2023. 😆🔬

pubmed.ncbi.nlm.nih.gov/36808637/

Here is another study supporting the role of TRPS1 #IHCPath in MPDs/EMPDs, which my initial studies proposed 2–3 years ago. Despite the major pushback and rejection from the #dermpath community at the time, I am glad to see more and more studies confirming our initial impression. 😆🔬

🚨 Hot off the press! The most comprehensive open-access review of TRPS1 and its applications in #dermpath is now available. Everything you need to know, based on our 4+ years of experience, is in one place. Check it out! 😆🔬

www.jpatholtm.org/journal/view...

#MDACCPath #IHCPath #TRPS1

Did you know “Pautrier microabscess” was mistakenly named after Pautrier? It was actually Darier who initially described it in MF, but repeated citation of incorrect information by US #dermpath led to this misconception. Don’t trust everything you see in the literature until you verify the facts! 😆🔬

Looking for a unique #pathology fellowship experience? 😆🔬

#MDACCPath has spots open! You’ll see once-in-a-lifetime cases (quite often) and learn from some of the best in the field.

If you’re even a little interested, apply! You won’t regret it.

It’s been a while since I shared a case.

Did you know this immunoprofile, especially the diffuse TRPS1 immunoreactivity, strongly favors primary EMPD over secondary EMPD? Give it a try if you haven’t used it in your practice. 😆🔬

#dermpath #IHCPath #MDACCPath

🚨Spoiler alert: Here’s a key pitfall almost no #dermpath textbook covers—SPTCLs can often show marked gamma/delta T-cell populations, mimicking pcGDTCL. A diagnostic trap you’ll want to know about. Our paper is coming soon—stay tuned! 😆🔬

#dermpath #hemepath #MDACCPath

🚨Spoiler alert: Primary cutaneous NUT adnexal carcinoma can metastasize—but long-term outcomes remain unclear. We're about to report an almost 20-year follow-up on this new entity. Stay tuned! 😆🔬🧬

#dermpath #pathology #molpath #IHCPath #MDACCPath

Exciting news! The May issue of The American Journal of Dermatopathology is out, and our paper is featured on the cover! What a great way to kick off the month. That gene fusion schematic? Pretty much our signature move at this point! 😆🔬🧬🎉

#dermpath #pathology #molepath #MDACCPath

Shoutout to our amazing #MDACCPath #IHCPath team for making work fun! 😆🔬🎨🎉

We had an Easter egg hunt in the lab, and I got to decorate my microscope with the treasures I found. Wishing everyone a joyful Easter weekend! 🐣🪺

#pathology

Happy Friday #dermpath! 😆🔬

Two of our articles were selected as Editor’s Choices in this month’s AJDP — and one even landed the front cover, featuring this photogenic gene schematic! 🧬🎨🎉

#MDACCPath #molepath #pathology

Weekend non-#dermpath special. 😆🔬

Here are photogenic intracytoplasmic inclusions or morulae ("mulberry-like" microcolonies of bacteria) in human granulocytotropic anaplasmosis (formerly known as human granulocytic ehrlichiosis). 🐛🧫🦠

#pathology #hemepath #MDACCPath

#PathSky 12F with an intra-articular middle finger mass.

Do you see what I see? 😆🔬

Pseudoepitheliomatous hyperplasia and dermal granulomatous inflammation with multinucleated giant cells. That’s it? Nope, keep looking and you will find the cause of these histopathologic changes—Medlar bodies of chromoblastomycosis!

#dermpath #IDpath #MDACCpath

#slidearchiveseries metastatic prostatic adenocarcinoma involving adrenal gland #gupath #pathsky

IU Pathology and IUHMG are recruiting anatomic pathologists in:

🔬 Pediatric Pathology
🔬 Head & Neck Pathology
🔬 Thoracic-Pulmonary Pathology
🔬 Dermatopathology
🔬 Gastrointestinal Pathology

Additional subspecialty training is welcome!
🔗 indiana.peopleadmin.com/postings/28097

Teen M with obesity, long term skin roughness, hyperpigmentation, confluent lesion and affecting skin fold and back.
#pedipath #dermpath #Pathsky

Beautiful example of reticular perineurioma with IHC obeying textbooks

(60s, male, finger mass)

#pathsky #bst #dermsky

New Year #dermpath special! 😆🔬

What about a case of Merkel cell carcinoma showing diffuse DLL3 (delta-like protein 3) expression?

DLL3 is under investigation as a potential biomarker for DLL3-targeting antibody-drug conjugates.

#IHCPath #MDACCPath #pathology