Lucas Massoth

#PathSky Laryngeal mass, older adult male. Primitive, highly vascular round cell neoplasm for the most part.

This is a duodenal mass is a patient with inflammatory bowel disease presenting with 1 week of nausea and vomiting. What IHC do you want to order?
#pathsky #pathology #histology

PRKAR1A

#PathSky 34M with a jet-black mass next to the seminal vesicle. Melanoma? A very occasional psammoma body was present, and expression of PRKAR1A was completely lost. Malignant melanotic nerve sheath tumor (previously “melanotic schwannoma”) in an unusual location.

Desmin

#PathSky I’m afraid I need 6 images for this one…Older adult with a large retroperitoneal mass. Most of it looks like this. Desmin (shown), SMA, and caldesmon are strongly positive.

Multiple nodules (slightly polypoid) protruding from nasal mucosa of a dog. The nodules are only slightly darker pink than the more normal mucosa.

Large, perhaps 200-micrometer-diameter, spherical organisns with a trilaminar wall and multiple smaller structures inside. It lies in the submucosa of the nose and is surrounded by macrophages, lymphocytes and plasma cells.

Spherical organisms of variable diameter but typically very large, with a thick capsule and grainy contents. These structures have thick walls, but only the largest has a trilaminar wall. The organisms are in the submucosa of the nose and are surrounded by macrophages, lymphocytes and plasma cells. Some macrophages contain hemosiderin.

Large spherical organisms of variable diameter with a thick capsule and granular contents. Some have a nucleus visible in the center. The largest is partially collapsed and has a trilaminar wall. The walls of smaller (developing) organisms only have one layer.

Here is a bipartisan #pathology case. It's relevent to DVMs and MDs. Lots of red (at least pink) and blue, too.

Rhinoscopy and nasal biopsy from a dog. What’s your diagnosis? It's a classic.

#vetpath #pathsky #Mesomycetozoea #pathology #respiratorypathology #endoscopy #rhinoscopy

SS18::SSX fusion protein IHC

#PathSky. Mass next to knee, 27F. A hypocellular tumor with striking vascular changes, like we see in pleomorphic hyalinizing angiectatic tumor or schwannoma. But also some small fascicles of monomorphic spindled cells and a calcification. SS18::SSX fusion antibody +. Sneaky synovial sarcoma.

Small intestine from a dog with a predominately histiocytic infiltrate. Macrophages contain numerous, very small organisms.

Small intestine from a dog with chronic inflammation.

Now that I have a few followers, most of whom are pathologists, I thought I'd give you an unknown. This is small intestine from a dog. What's your diagnosis? Any rule-outs? Our Biopsy Conference participants had one principal rule-out with two alternates.

This was an image of a bone marrow biopsy (the biopsy was collected while the patient was conscious) and this patient has likely been cured of this highly treatable leukemia

S100

OCT2

#PathSky
Scalp mass, 33M. Just a nice example of soft tissue Rosai-Dorfman disease. I think this low power “pale->pink->blue” look is a good low power clue. In addition to S100 protein, Karen Rech’s group here at Mayo have shown OCT2 to be valuable in this dx. pubmed.ncbi.nlm.nih.gov/33177341/

This, as featured in my avi, was a cute little finding. Enterobius in a tubular adenoma #pathology #GIPath #histology #histopathology

A nasty testis in a teenager. Any guesses? #pathsky #gupath

Nodular lymphocyte predominant Hodgkin lymphoma exhibiting characteristic PD1+ T-cell rosettes around tumor cells

#Pathsky #Pathology #Hemepath

The cells with blue nuclei and granular cytoplasm are the promyelocytic leukemia cells. The fewer red cells are red blood cells in marrow sinusoids

I called this a tonsillar fibroma since I didn't know what else to call it, but it's a great section! Almost like the tonsil has its own uvula. #pathsky #pathology

Tonsillar Lymphangiomatous Polyps: A Clinicopathologic Series of 26 Cases - Modern Pathology Modern Pathology - Tonsillar Lymphangiomatous Polyps: A Clinicopathologic Series of 26 Cases

www.nature.com/articles/388...

KIT

CD31

#PathSky

I try not to talk about it, but sometimes I look at bone cases. Lytic sacral lesion, 69M. Among the many IHC it was sent with, CD31 and KIT were diffusely positive, but other endothelial and GIST markers were negative. Dx? Anything else you’d like?

Agree, plus maybe a PD1 and OCT2. Sort of moth-eaten at low power

Acute promyelocytic leukemia, Giemsa stain

#pathsky #medsky #pathology #oncology #hemepath

Nice pics!

Hybrid tumor: Oncocytoma and Chromophobe Renal cell Carcinoma! #GUpathsky #pathsky #pathology #surgicalpathology #pathart #Nephsky

Nice case. Tell Petur Nielsen to make an account!

GMS!

Ok, my third attempt at a first post. I like surgical pathology and sharing cases.

New genetic promiscuity. Superficial neurocristic EWSR1::FLI1 fusion tumor. Same fusion as Ewing sarcoma but benign. There is life in this whole morphology thing yet.

pubmed.ncbi.nlm.nih.gov/38866368/

#PathSky

Nice case. I suspect it was a welcome surprise for the oncologist and the patient!

Patient with #CLL and geographic necrosis. What is dx? #pathsky #hemepathsky #hemesky #medsky

HSV lymphadenitis?

🔬Quiz yourself with a past #EmoryCoTW

A bone marrow aspirate shows cytoplasmic vacuoles in myeloid and erythroid precursors (see images).

Which nutrient deficiency should be considered?

#PathSky #Pathology #PathResidents #MedSky #Path2Path #PathMatch25 #PathMatch2025

CD68 immunohistochemical stain

S100 immunohistochemical stain

Granular cell tumor (GCT), tongue, H&Es, 10x and 40x & CD68 and S100, 20x: Large round to oval tumor cells with indistinct eosinophilic, granular cytoplasm - CD68, S100, and SOX10 positive!
#pathology #pathsky #surgicalpathology #granularcelltumor #gct #headandneckpathology #pathart

Touch preparation of high-grade mullerian serous carcinoma presenting as a large abdominal mass, performed at the time of frozen section. Although not always additive, touch preparations can be a useful adjunct to evaluate tumor morphology intraoperatively

#pathsky #medsky #pathology #gynpath

So glad you asked! To start, you can’t just train a set on randomly submitted diagnostic information. You need good curated information about the patients’ history. You need appropriate numbers of both positive and negative examples of all target conditions. 1/4 #pathsky #medsky