Histology & Images Flashcards
What type of tissue is this?
What type of secretory cells are principally found in each layer: A, B, & C

Gastric epithelium
A) Chief cells
B) Parietal Cells
C) Surface Mucous Cells
What type of tissue is this?

Gastric Epithelium
(The mucosal surface of the stomach is lined by a simple columnar epithelium consisting uniformly of surface mucous cells.
Secretions of the surface mucous cells protect the stomach from self-digestion. Each cell contains an apical mass of mucus which, unlike the mucus in other mucous cells, is acidophilic.
The mucosal surface is invaginated into numerous gastric pits, each of which opens freely onto the mucosal surface)
What type of tissue is this?
What structures are outlined in white?

Gastric epithelium
Gastric glands are outlined in white.
Every gland opens into a gastric pit (with several glands per pit).
Most of the bulk of the gastric mucosa is occupied by secretory cells of the gastric glands, primarily parietal cells and chief cells, together with lamina propria.
Cells with basally basophilic cytoplasm and basal nuclei are the chief cells.
Cells with conspicuous eosinophilic cytoplasm and centrally located nuclei (sometimes paired) are the parietal cells. (middle)
What type of tissue is this?

Small Intestinal Epithelium
The mucosa of the small intestine is lined by simple columnar epithelium composed primarily of absorptive cells (enterocytes), with scattered goblet cells.
Lamina propria forms the core of each villus.
What are “lacteals” & what is their purpose?
Lacteals are lymphatic channels in each of the villi of the small intestine.
Lacteals provide passage for absorbed fat (the chylomicrons) into the lymphatic drainage of the intestine.
What type of structures are “Peyer’s Patches” & where are they located?
Peyer’s patches are lymphoid structures located in the mucosa of the ileum
What type of tissue is this?
What are the accumulations of lymphoid tissue referred to as?

Ileum (small intestine)
The conspicuous patches of lymphoid tissued are called “Peyer’s patches,” which may protrude into the lumen and also extend into the submucosa
What type of tissue is this?

Small intesteine mucosa (jejunum)
Auerbach’s & Meissner’s plexus –> myelinated or unmyelinated?
Unmyelinated
Where is Auerbach’s plexus located?
What are these structures responsible for?
Auerbach’s plexus is located between the circular and longitudinal smooth muscle layers of the muscularis externa.
Coordinated contraction of these layers is responsible for rhythmic peristalsis.
(image shows intestinal muscularis externa & serosa)

Where is Meissner’s plexus located?
What is it’s purpose?
Meissner’s plexus is located within the submucosa.
Neurons in this plexus influence the smooth muscle of the muscularis mucosae, including the smooth muscle fibers which extend into intestinal villi. These control secretions throughout the GI tract.
Diagnosis?

H. pylori Gastritis
Gastritis is often accompanied by infection with Helicobacter pylori. This small curved to spiral rod-shaped bacterium is found in the surface epithelial mucus of most patients with active gastritis. The rods are seen here with a methylene blue stain.
What is the name of the nerve cell bodies seen in this image of intestinal submucosa?

Meissner’s Plexus
The submucosa consists of loose, fibrous connective tissue which facilitates motility of the GI tract by permitting the mucosa to move flexibly during peristalsis.
Within the submucosa lies Meissner’s plexus (or, the submucosal plexus) of parasympathetic nerve fibers and cell bodies, which influence smooth muscle of the muscularis mucosae.
Diagnosis?
Treatment?

Menetrier Disease (rare)
- excessive TGF-alpha secretion
- diffuse hyperplasia of the foveolar epithelium
- treatment- supportive, TGF blockers, surgery
Diagnosis?

Linitis Plastica
Diagnosis?
(this is in stomach)

Large B-cell Lymphoma
Type of ulcer?

Perforated Ulcer
Type of ulcer?

Bleeding ulcer
(w/ clot – upwards arrow)
Type of ulcer?

Clean-based ulcer
Arrows (top to bottom):
- Relatively normal mucosa
- Erythema/inflammation
- Clean based ulcer crater
Diagnosis?

Gastric Adenocarcinoma
Diagnosis?

Gastrointestinal Stromal Tumor (GIST)
Diagnosis?

Lymphoma of GI tract
(stomach)
Diagnosis?

Iron Pill Gastritis
(Iron supplementation pills may cause erosions, or ulcers. Grossly: grayish or blueish mucosal patches.
Will also see a granular brown pigment attached to the mucosal surface. Stain positive with iron stain.)
Diagnosis?

Atrophic Gastritis
(Autoimmune)
In these histologic images of GIST, which type is each?

Left = Spindle Cell Type
Right = Epithelioid Cell Type
Diagnosis?

Cobblestoning of Colon
Dx = Ulcerative Colitis
- 50% confined to rectum
- only 10-30% extend proximal to splenic flexure)
Diagnosis?

Aphthous Ulcer
Dx = Ulcerative Colitis
- 50% confined to rectum
- 10-30% extend proximal to splenic flexure
Diagnosis?

Ulcerative Colitis
Diagnosis?

Ulcerative Colitis
Diagnosis?

Chronic Ulcerative Colitis
“Lead Pipe” appearance
Diagnosis?

Dx = Crohn’s Disease
Aphthous Ulcer can be seen
Diagnosis?

Ileitis
(Crohn’s Disease)
Diagnosis?

Crohn’s Disease
path = Stricture w/ “string sign”
Separation of normal from involved intestine reflects luminal narrowing, thickening of bowel wall, & mesenteric hypertrophy.
A combo of transmural thickening & irritative spasm produces the classical “string sign” in the terminal ileum.
Diagnosis?

Crohn’s Colitis (Barium enema)
Skip lesions & relative rectal sparing are most distinguishing characteristic of Crohn’s from UC
Diagnosis?

Crohn’s Disease
Path = Mesenteric Sinus (clefts)
Deeply undermining clefts are a histological characteristic of Crohn’s disease & can ultimately develop into sinus tracts that penetrate into the surrounding mesentery
Diagnosis?

Crohn’s Disease
Path = Mesenteric Sinus
Sinus tracts can be demonstrable on x-ray as curvilinear collections of contrast extending from the bowel lumen deeply into the mesentery
Diagnosis?

Crohn’s Disease
Path = Pelvic Abscess
The CT scan shows a large pelvic abscess containing a small amount of air above a large purulent collection.
This is seen contiguous to an inflamed loop of small bowel with markedly thickened walls and surrounding mesenteric inflammatory stranding.
Diagnosis?
Path (arrow)?

Dx = Crohn’s Disease
Arrow = Segmental distribution of small bowel mural thickening
Diagnosis?

Ulcerative Colitis
Left = Pseudopolyps
Right = Rectal narrowing
Diagnosis (for each)?
Each are examples of fecal leukocytes from patients w/ bacterial colitis
a) Salmonella
b) Ulcerative Colitis
Diagnosis?

Celiac Sprue/disease
Path = Mucosal Mosaic Pattern
- Endoscopic view of jejunum after spraying methylene blue dye solution showing mucosal mosaic pattern
Diagnosis?

Celiac Sprue/disease
Path = Scalloping of intestinal folds
Endoscopic view of jejunum showing scalloping of folds
Diagnosis?

Whipple’s Disease
- pill capsule pictures
(this is a picture of what the normal jejunum should look like)

Which area of GI tract is this?

Duodenum
b/c of submucosal, mucinous Brunner’s Glands (area w/ line on left)
Acquired vs. Meckel Diverticulum?
Muscularis propria does not follow Acquired Diverticula (A)
Meckel Diverticula (B)

Diagnosis?
(Left is normal, Right is path)

Celiac Disease or Crohn’s Disease
Path = Intestinal Scalloping (flattening of villi)
Diagnosis?
A. Specific histology for this disease
B. PAS stain positive
C. Acid-Fast negative

Whipple’s Disease
A. Lamina propria expansion by Foamy Histiocytes
*note: this histopathology is also seen in Mycobacterium avii — more common in AIDS patients
Diagnosis?

Giardia lamblia
*crescent-shaped, basophilic, intraluminal protozoa
Describe the pathology seen here

Hemorrhage & surface area destruction of the tips of the plicae
(Seen in early ischemic damage)
Describe pathology seen here

Necrosis/hemorrhaging that has expanded into submucosa
@ bottom, can see underlying vessel w/ thrombus
Describe the pathology seen here

Full thickness necrosis
(seen in later stages of ischemia)
(usually need surgical intervention here, since external mucosal layer is involved, i.e. transmural ischemia)
Describe the pathology seen here.
What conditions that exhibit pathology can cause intestinal ischemia?

Fibrinoid necrosis (of Mesenteric artery in this case)
Arteritis conditions such as Henoch Schonlein purpura can cause intestinal ischemia characterized by fibrinoid necrosis, as is seen here
Describe the pathology seen here.
Dx?

Combined acute & chronic inflammation
Black arrow: Crypt abscess
Black, open arrow: Intense lamina propria chronic inflammation
Dx = Crohn’s Disease
Describe the pathology seen here.
Dx?

Black curved arrow = Neutrophilic microabscess erodes through the surface
Black arrow = Cryptitis is present in the surrounding mucosa
Black, open arrow = Epithelium on either side of the ulcer is regenerative, not to be mistaken for dysplasia
Dx = Crohn’s Disease of the Ileum w/ an aphthous ulcer
Describe the pathology seen here.
Dx?

Deep fissuring ulcer (Black arrow) that extends into the muscularis propria (Black, open arrow).
The fissures contain pus & granulation tissue & are lined by histiocytes & giant cells.
Dx = Crohn’s disease
Describe the pathology seen here
Dx?

Black open arrow = Chronic mucosal changes
Black arrow = Transmural lymphoid aggregates
Dx = Crohn’s Disease (lower power view in SI)
Describe the pathology seen here.
Dx?

Distortion of mucosal architecture
- Bizarre shaped branching crypts
- Crypt shortfall – basal plasmacytosis
- Crypt dropout
Dx: Crohn’s Disease (chronic features)
**Crypt dropout, shortfall, & bizarre shape/branching also seen in Ulcerative Colitis
Describe the pathology seen here.
Dx?

Epithelial Metaplasia
- Pseudopyloric metaplasia
- Paneth cell metaplasia in left colon
Dx = Crohn’s Disease (chronic changes)
**this epithelial metaplasia w/ paneth cell hyperplasia is also seen in Ulcerative colitis
Describe the pathology seen here.
Dx?

Chronic inactive colitis
- Architectural & metaplastic changes persist after active inflammation has resolved
Dx = Crohn’s Disease (chronic changes)
Describe the pathology seen here.
Dx?

Non-caseating Granulomas
- Hallmark of Crohn’s Disease (35%)
- Active or uninvolved
- Intestinal wall or mesenteric lymph nodes
- Cutaneous (“metastatic Crohn Disease”)
Dx = Crohn’s Disease (chronic changes)
Diagnosis?

Pseudomembranous Colitis
(initial gross appearance)
Diagnosis

Pseudomembranous Colitis
(later stages)
(proteinaceous necrotic, debris on colon surface)
Describe the pathology seen here.
Dx?

Psuedomembrane pouring into lumen (proteinaceous material)
Dx could be Psuedomembranous Colitis, ischemia, or a necrotizing infection
Diagnosis?

Pseudomembranous Colitis
Exudate forms an eruption, reminiscent of a volcano
Patient presents w/ watery, non-bloody diarrhea & cramping abdominal pain.
Endoscopy is normal. The following histology is seen.
What is the Dx?

Microscopic Colitis - Collagenous
Patient presents w/ watery, non-bloody diarrhea & cramping abdominal pain.
Endoscopy is normal. The following histology is seen.
What is the Dx?

Microscopic Colitis - Lymphocytic
Describe the pathology seen here.
Dx?

A.Low-power view of ulcerative colitis. Note the restriction of inflammation to the mucosa (white arrow), with the submucosa (black open) and muscularis propria (black curved) left intact.
B.The lamina propria shows an intense infiltrate of lymphocytes and plasma cells. There is evidence of glandular distortion. A prominent crypt abscess is seen.
Dx = Ulcerative Colitis
Describe the pathology seen here.
Dx?

Epithelial metaplasia (mostly Paneth cell)
Dx = Ulcerative colitis
**note this is also seen in Crohn’s Disease
Describe the pathology seen here.
Dx?

Architectural distortion of the mucosa, indicative of chronic injury. Several abnormally shaped (black open) and branched (black arrow) crypts are visible.
Dx = Ulcerative Colitis
Describe the pathology seen here.
Dx?

Hematoxylin & eosin shows an inflammatory pseudopolyp. Note the reactive epithelial atypia (black arrow) (not to be overinterpreted as dysplasia) and surface erosion (black open).
Dx = Ulcerative Colitis
Describe the pathology seen here.
Dx?

Note the lack of acute inflammation & sparse chronic inflammation. Crypt distortion (white arrow) & areas devoid of crypt (white open) are apparent.
- Fibrosis, mucosal atrophy, distorted mucosal architecture
Dx = Chronic Colitis (quiescent)
Describe the pathology seen here.
Dx?

FIliform Polyposis
Dx = Ulcerative Colitis
Describe the pathology seen here.
Dx?

Epithelioid histiocytes may be present, but there is no formation of granulomas.
Dx = Ulcerative Colitis
These 3 complications are seen ass’d w/ what disease?

Ulcerative Colitis
Describe the pathology seen here.
Dx?

Hyperchromatic epithelium (black arrow).
This polyp is in an area affected by chronic colitis – note mucosal distortion (black open) – & is best regarded as dysplasia-associated lesion/mass
Dx = Polypoid low-grade dysplasia in Ulcerative Colitis
Describe the pathology seen here.
Dx?

High-power view of dysplasia-associated polyp. The crypts are lined by epithelium w/ pseudostratified, hyperchromatic nuclei (white arrow) & the changes extend to the mucosal surface (black arrow).
Dx = Ulcerative colitis w/ polypoid low-grade dysplasia
Describe the pathology seen here.
Dx?

This is an area of high-grade dysplasia arising in UC. Note architectural complexity (white arrow) & markedly atypical epithelium w/ enlarged nuclei that have lost polarity (white open)
Dx = Ulcerative Colitis w/ high-grade dysplasia
Describe the pathology seen here.
Dx?