Pathology

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This is the mander.xyz pathology community! All topics relating to pathology are welcome. Please respect mander.xyz rules, particularly involving the focus on science and avoidance of political discussion. Intersection with politics may be tolerated as long as the discussion is constructive and science remains the focus; as a general rule, political content posted directly to the instance’s local communities is discouraged and may be removed.

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mander.xyz Pathology Community Overview and Post Templates (mander.xyz)

submitted 2 days ago* (last edited 2 days ago) by TP53@mander.xyz to c/pathology@mander.xyz

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Welcome! This is the mander.xyz pathology community. The goal of this community is to provide a space for the discussion of pathology as a field as well as share interesting (non-identified) cases and approaches to diagnosis.

Interesting cases should follow this format as closely as possible (please copy/paste):

**Clinical**: [insert brief clinical information here; omit age and sex/gender unless relevant to the case, and if it is relevant, provide decade age ranges such as 0-1 years, 1-10, 11-20... 81-90. Do not give an age greater than 90.]

**Histology**: [insert either a link to a de-identified whole slide image or take de-identified histology still images and upload them as images; please use captions as appropriate.

**Special/ancillary testing**:

[Enter any special or ancillary testing here. These can sometimes spoil the diagnosis, so wrap them in spoiler text to help users self-test using the already provided information first]

**Diagnosis**:

[Enter diagnosis and explanation here]

Endocarditis (sh.itjust.works)

submitted 6 hours ago by Apytele@sh.itjust.works to c/pathology@mander.xyz

1 comments fedilink

(I’m sorting communities by new and adding to any I have decent content for)

Soft tissue pathology case (mander.xyz)

submitted 2 days ago* (last edited 2 days ago) by TP53@mander.xyz to c/pathology@mander.xyz

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Clinical: Pharyngeal mass

Histology:

Approximately 20% of the tumor looks like this.

Approximately 80% of the tumor looks like this. The mitotic rate is less than 10/10 high-power fields (at most 5 figures/1mm^2^). Necrosis was not seen.

Special/ancillary testing:

Testing performed on a region like image #2 above:

Smooth muscle actin: scattered positive
Desmin: scattered positive
CD34: positive (non-specific)
S100: negative
SOX10: negative
AE1/AE3: negative
STAT6: negative
ALK1: negative
beta-catenin: negative
MUC4: negative
MDM2: strongly positive in most tumor cells
CDK4: strongly positive in most tumor cells

Diagnosis:

Following immunohistochemical testing, we had a differential diagnosis of cellular well-differentiated liposarcoma (WDLPS) and a low-grade dedifferentiated liposarcoma (DDLPS). In the 5th edition of the WHO classification of soft tissue and bone tumors, they note that "low-grade DDLPS is virtually indistinguishable from cellular WDLPS". Which is fun to read when you're trying to sign out a case like this.

We identified a helpful publication (Graham et al., 2023) that stratified tumors like this into 1) classic WDLPS without the non-lipocytic components like we see in this case, 2) tumors with non-lipocytic areas and < 5 mitotic figures/10 HPF, and 3) tumors with non-lipocytic areas and 5 or more mitotic figures/10 HPF. They found that groups 1 and 2 performed similarly while group 3 tended to have a worse disease-specific survival compared to groups 1 and 2. Since we had at least 5 mitotic figures/10 HPF, after consultation with multiple pathologists, we felt that this was most in keeping with an FNCLCC intermediate-grade dedifferentiated liposarcoma (DDLPS).