Geronimo Junior MD

02/04/2026

🔬 Mapping Ulcerative Colitis: Distribution Patterns 🗺️
While Ulcerative Colitis (UC) classically starts in the re**um and extends proximally in a continuous fashion, its distribution can vary significantly based on patient demographics and clinical history
Here is a quick summary of the main patterns you might encounter:
🔹 The Classics: • Proctitis: Inflammation is limited to the re**um
• Proctocolitis: The classic presentation, extending from the re**um into the left colon
• Pancolitis: Involvement of the entire colon
This can sometimes be accompanied by 'backwash ileitis' (inflammation extending into the terminal ileum)

🔴🔹 Atypical & Specific Scenarios:
• Cecal Patch: A classic left-sided presentation but with an isolated patch of inflammation in the cecum
• PSC-Associated UC: Patients with Primary Sclerosing Cholangitis often show distinct disease distribution patterns
• Pediatric UC: Unlike adults, children with UC frequently present with re**al sparing
• Post-treatment UC: Medical therapy can alter the classic continuous pattern, leading to patchy, discontinuous disease areas

01/04/2026

31/03/2026

Patologia Brasil

31/03/2026

🔬 Practical Tips: Measuring Depth of Invasion 📏 Evaluating tumors with submucosal invasion requires close attention to morphological details. Here are some essential tips based on the image:
• Haggitt levels: The Haggitt level of invasion in pedunculated tumors is composed of the head, neck, stalk, and beyond the stalk • Starting Point: The depth of invasion should be measured from the neck of the polyp (Haggitt level 2) • Disrupted Muscularis Mucosae: In cases with disrupted muscularis mucosae, the depth of submucosa invasion is measured from a continuous line of the residual muscularis mucosae • The Power of IHC: To highlight an indistinct muscularis mucosae, immunohistochemistry for desmin may be performed.

30/03/2026

❎ TIPS ❎

1. Complementary Tests: MMR IHC and MSI testing are both essential and complementary tools for solid tumors.
2. Evolving Definitions:MMR deficiency isn't just "complete loss"; partial or clonal loss is now a recognized abnormality.
3. Mandatory Controls: Always check internal positive controls; without them, absent tumor staining is uninterpretable.
4. PMS2 is Key:MLH1 IHC alone can miss defects, so adding PMS2 increases detection sensitivity.
5. Watch for Clonal Loss: Sharply demarcated regional loss of staining often indicates true gene alterations like Lynch syndrome.
6. Fixation Matters: Poor tissue fixation can reduce staining intensity and falsely mimic MMR protein loss.
7. Mind the Tumor Type: Most MSI panels are calibrated for colore**al cancer, which can lower their sensitivity for other tumors.
8. The MSI Paradox: Some non-colore**al tumors are MMR-deficient by IHC but not MSI-High, warranting further genetic workup.
9. Sequential Strategy: Use MMR IHC as the first-line test, followed by MSI testing if results are doubtful.
10. The NGS Advantage: NGS-based MSI detection allows simultaneous assessment of tumor mutation burden (TMB) and actionable genes.

28/03/2026

25/03/2026

🟡Uma grande honra participar do XI Congresso Internacional Oncologia D'OR e debater a patologia digital.
Sob a coordenação do Dr Fernando, teremos como palestrante dra Isabella e aquele que me introduziu na patologia digital: O grande irmão Rajendra !

🔴 It's a great honor to participate in the XI D'OR International Oncology Congress and discuss digital pathology.

Under the coordination of Dr. Fernando, we will also have Dr. Isabella as a speaker, and the one who introduced me to digital pathology: my great brother Rajendra!

25/03/2026

I’m sharing a very interesting case: a cutaneous granular cell tumor.

The first slide is centered on the lesion, and in this context, the diagnosis is straightforward... Classic morphology that essentially makes immunohistochemistry unnecessary.

However, what I really want to highlight in this case is what happens when we receive a superficial sample.

In the next two images, you can see the marked pseudoepitheliomatous hyperplasia that can be associated with these tumors. In such situations, the granular cells may be very subtle and scattered between the squamous nests.

This can easily lead to a misdiagnosis of squamous cell carcinoma.

STAY TUNED !

23/03/2026

✔️F, 40yo, multiple liver nodules.
💢A beautiful case I’m reviewing this Monday.
- What’s your dx?
- Ask me for a marker.