Anatomic pathologist, dermatopathologist | Developer of https://xitter.cf/t.co/mXLTq4Cami, https://xitter.cf/t.co/S3gFkqZKpN
Vancouver, Canada
Joined October 2022
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Couldn't be more excited to announce the launch of pathlibrary.com, the virtual slide site I wish had existed during my pathology residency. You can:
- Order special stains to work up cases
- See annotated histologic features
- Prepare for exams with board-style questions
15M with colonic polyps showing arborizing stalks of smooth muscle. What's the expected germline mutation in this patient?
WSI and answer:
pathlibrary.com/slidebox/?ca…
Mesenchymal chondrosarcoma shows a histologic triad of:
* Mature cartilage
* Atypical small round blue cells
* Thin-walled, branching vessels
See the labelled whole slide at:
pathlibrary.com/slidebox/?ca…
New pathlibrary.com cases dropped: We're past the 1450 cases mark. Try your hand at working up this challenging soft tissue tumor (case #1450).
(Hint: FOSB IHC+)
Acute vacuolar interface change with dyskeratosis: A pattern with a narrow differential:
* Erythema multiforme, TEN/SJS
* Fixed drug eruption (usually has dermal melanin)
* Acute GvHD
* Reactive infectious mucocutaneous eruption (RIME)
WSI & discussion:
pathlibrary.com/slidebox/?ca…
Chronic colitis with pyloric gland metaplasia (top left) and Paneth cell metaplasia (bottom right - their granules look similar to eosinophil cytoplasm). Paneth cells are normal in the right side of the colon but signify colitis in the left side.
WSI: pathlibrary.com/slidebox/?ca…
A case of Ewing sarcoma metastatic to the skin with a classic "light cell/dark cell" appearance.
See the labelled whole slide at: pathlibrary.com/slidebox/?ca…
A case of pityriasis lichenoides showing its classic features: Mounds of parakeratosis, red cell extravasation, lichenoid inflammation, and lymphocytic exocytosis.
Labelled whole slide: pathlibrary.com/slidebox/?ca…
A bizarre parosteal osteochondromatous proliferation (BPOP) with disorganized cartilage, disorganized bone, and bland fibrous tissue.
BPOP is benign but locally destructive and has a propensity for the small bones of the hands & feet.
Labelled WSI: pathlibrary.com/slidebox/?ca…
A case of a Wolffian tumor (previously female adnexal tumor of probable Wolffian origin/FATWO).
These lesions typically show a variety of architectural patterns including tubular, cystic, and solid. Tubules filled with eosinophilic material are common.
WSI: pathlibrary.com/slidebox/?ca…
Atypical endometrial hyperplasia (top) and background benign endometrial glands (bottom). Note the contrast between small, dark benign nuclei and enlarged, pale, vesicular nuclei of atypical hyperplasia.
Labelled whole slide: pathlibrary.com/slidebox/?ca…
A desmoplastic nodular medulloblastoma showing characteristic paler areas among more densely-packed small round blue cells.
Molecularly, this subtype of medulloblastoma tends to be SHH (sonic hedgehod pathway)-activated.
See the whole slide at:
pathlibrary.com/slidebox/?ca…
Hyalinizing trabecular tumor is an aptly-named benign thyroid neoplasm. Ki-67 shows an unusual membranous pattern in these lesions.
What other lesion characteristically shows this Ki-67 staining pattern? Answer at: pathlibrary.com/slidebox/?ca…
A verrucous cyst showing the same papillomatosis, hypergranulosis, and coarse keratohyalin granules of verruca vulgaris.
These lesions may result from low-risk HPV infection of pre-existing epidermoid cysts.
Whole slide:
pathlibrary.com/slidebox/?ca…
Plexiform fibrohistiocytic tumors are rare soft tissue tumors of intermediate malignant potential.
They have a plexiform (woven) architecture with fascicles of histiocytoid cells in a collagenous stroma.
See the whole slide:
pathlibrary.com/slidebox/?ca…
A case of calcifying fibrous tumor, an entity characterized by dense, compact collagen and scattered calcification. These lesions may represent burnt-out IgG4-related disease.
Whole slide:
pathlibrary.com/slidebox/?ca…
A case of hyaline vascular Castleman disease showing atretic (miniaturized) germinal centers with transgressing hyalinzed vessels as well as germinal center "twinning" (two germinal centers surrounded by a single mantle zone).
Labelled WSI: pathlibrary.com/slidebox/?ca…
A case of acantholytic squamous cell carcinoma in situ.
Acantholysis in squamous cell carcinoma was once thought to confer a worse prognosis, but this is no longer thought to be the case.
Whole slide:
pathlibrary.com/slidebox/?ca…
