Interactive lab

Five activities

Every activity uses real chapter content and keeps your progress in both study modes. Each also appears inside the topic where it helps most.

Centerpiece

Four specimens: look, decide about invasion, choose a stain, sort grade from stage, then take one more clue.

In context: 7.2 Dysplasia and invasion →

Centerpiece · Tumor Pathology Case Lab

Tumor Pathology Case Lab

Four specimens, each worked the way a pathologist works: look first, decide whether the basement membrane has been crossed, choose the stain that answers the question, sort the findings into grade and stage, then take one more clue and say what it changes.
Bronchial biopsy: irregular nests of atypical squamous cells in stroma; one nest surrounds a bright pink, concentric whorl of keratin.
Bronchial biopsy, H&ECh. VII cases p.5

Clinical history

A 60-year-old man has 4 months of weight loss, wheezing and breathlessness. He has smoked two packs a day for 40 years. A chest radiograph shows a 10-cm mass in the left lung, and bronchoscopy shows the left main bronchus obstructed. A biopsy is taken.

Before you answer, look for

  • Are the cells arranged in nests, glands or sheets?
  • Is anything being made by the cells: keratin, mucin, matrix?
  • Are the nests confined to an epithelial layer, or sitting in stroma?
  1. 1. Look first
  2. 2. Has it invaded?
  3. 3. Choose a stain
  4. 4. Grade or stage
  5. 5. One more clue

Step 1 · Look first

What do you call this, and what is the lineage clue?

Decide benign or malignant first, then name what the cells are making.

Morphology

Three schematics of one epithelium with basement membrane, atypia and stroma overlays; decide which is invasive and what proves it.

In context: 7.2 Dysplasia and invasion →

Morphology comparison · Layers

Where are the cells?

Three schematics of the same squamous epithelium at one scale: epithelium above, stroma with a lymphatic and a vein below. Switch the overlays on and off, then decide which specimen is invasive and what the evidence is.
  1. Specimen A: squamous epithelium over stroma (teaching schematic)

    Specimen A

  2. Specimen B: squamous epithelium over stroma (teaching schematic)

    Specimen B

  3. Specimen C: squamous epithelium over stroma (teaching schematic)

    Specimen C

Teaching schematics, not micrographs. Orange outline: lymphatic. Red outline: small vein.

1 of 3

Which specimen shows invasion?

2 of 3 · answer the previous question first

Specimen A has severe atypia through its full thickness. Why is it not invasive?

3 of 3 · answer the previous question first

In specimen C, which finding establishes invasion?

0 of 3 answered correctly. Source: Lesson 7 Neoplasia, pp. 8 and 22; the same distinction is tested in Ch. VII Q2 and Midterm sim. Q5–Q6.

Causal chains

HPV oncoproteins, the invasion cascade and the two-hit hypothesis; events versus mechanisms.

In context: 7.3, 7.4, 7.5 →

Core activity · The Missing Arrow

The Missing Arrow

Complete the causal chain. Place the missing step by dragging a card onto a gap, or tap a card and then tap the gap. Some gaps need an event; others need the mechanism that links one event to the next.

A cervical squamous cell at the transformation zone is infected by HPV 16, and the viral genome integrates into host DNA. Complete the chain to a dividing, mutating clone.

Two gaps ask for a mechanism, the link that explains how one event causes the next. Don't put an event there.

  1. High-risk HPV 16 integrates into the host genome
  2. integration disrupts viral E2, which normally restrains E6 and E7
  5. p53 protein is degraded
  6. no p53 means no p21, no DNA-repair induction and no apoptosis signal
  9. Continuous proliferation of cells carrying unrepaired DNA damage
  10. each division adds mutations the cell can no longer check
  11. Dysplasia → carcinoma in situ → invasive squamous cell carcinoma

Cards

Tap or drag a card. Placing a used card moves it.

Look-alikes

Dysplasia vs in situ, in situ vs invasive, hamartoma vs choristoma, grade vs stage.

In context: 7.1, 7.2, 7.6 →

Core activity · Almost Twins

Almost Twins

Two look-alikes side by side. Decide what they share, then pick the clue that separates them and say why it works.

Look-alike A

Dysplasia (low grade)

basement membrane (intact)
Cervical epithelium, HPV positive (schematic).
  • Atypical nuclei: enlarged, hyperchromatic, high N:C ratio
  • Atypia confined to the lower layers; cells still mature toward the surface
  • Basement membrane intact
  • Often regresses, especially after HPV clearance

Step 1 · What they share

What do these two epithelia share?

Select every feature that both show.

Case reasoning

Change one laboratory value or one biopsy finding and decide whether the answer moves.

In context: 7.7 Paraneoplastic syndromes →

Core activity · One Fact Changes

One Fact Changes

Answer a case and name the decisive clue. Then exactly one fact changes. Decide whether the answer moves, and why.

1 · The original case

A 64-year-old man who has smoked for 40 years has a central lung mass and weight loss. Serum calcium is 3.4 mmol/L (13.6 mg/dL), phosphate is low and intact PTH is undetectable; a bone scan shows no metastases. Biopsy of the mass is pending.

Which tumor and mediator best explain the laboratory findings?

Which fact decided it?