Prostatic carcinoma - Rules!!

Rule 1: Prostatic carcinoma is suspected always on low power examination.

Rule of "Toos" (at low magnification):

1. Too small glands

2. Too crowded glands (with back to back arrangement)

3. Too clear glands

Three criteria for confirmation of malignancy (at high magnification):

1. Enlarged nuclei

2. Prominence of nucleoli

3. Loss of basal cells 


Additional features that indicate a malignancy:
1. Crystalloids
2. Glomerulations
3. Circumferential perineural invasion


Figure below - Shows benign prostatic acini with basal cells and luminal cells

Figures below - Prostatic adenocarcinoma

Hamartoma versus Choristoma

Hamartoma:

Disorganised but benign mass composed of cells indigenous to the involved site.

Choristoma:
Heterotopic rest of normal cells.

Biphasic Soft tissue tumours with epithelial component

1. Chondroid syringoma / mixed tumour of soft tissue
2. Malignant Peripheral Nerve Sheath Tumour
3. Synovial Sarcoma

Reboot Your Brain and leave a comment - Hemat Quiz 1

Quiz created by Kiruthiga Gnanasekaran with GoConqr

Quiz 1

Quiz created by Kiruthiga Gnanasekaran with GoConqr

Identify this artefact

Jones silver methanamine stain

Jones silver methanamine stain

Used to highlight basement membranes.

Used as a routine stain in renal biopsies.

Do you remember the principle of PAS stain? This one is similar to that.

JONES STAIN:

C-C bonds in carbohydrates (Eg:Glycogen) ----> Oxidised by periodic acid ----> Aldehyde ---> Reduces silver solution ----> Metalllic silver (Black)

PAS STAIN:
C-C bonds in carbohydrates (Eg:Glycogen) ----> Oxidised by periodic acid ----> Aldehyde ------> Schiff's reagent (Fuschin-sulphurous acid) ------> Alkyl sulphonate (magenta coloured compound).

• Structures that are stained magenta on a PAS stain will be black in Jones' stain.

Fig: Black lines (arrows) represent the glomerular and tubular basement membranes.
Arrow heads - Capillary walls.


Note: It is not specific for basement membranes, demonstrates any carbohydrate which can be oxidised to aldehyde. 

What is haematoxylin?

HAEMATOXYLIN:

• Derived from the wood Haematoxylum campechianum.
• It means bloodwood  - refers to the dark red colour (Haemato -  blood, xylon- wood)

• Campechianum  refers to the coastal city of Campeche on the Yucatan Peninsula, the locality of the heart wood.

Pic: Google

If Haematoxylum is red, how is haematoxylin blue?

• Haematoxylin has little or no staining capacity.
• Haematoxylin is oxidised to haematein which gives the blue colour.
• Oxidation - two methods - 1. Natural 2. Chemical

Haematoxylin versus Haematein:

If hematein is the dye and haematoxylin needs to be oxidised before it can stain, why not use hematein in the first place?

• If we start with hematein, oxidation will start to diminish the staining capacity right from the start, shortening the working life of the solution ☺☺

Mucormycosis - How to identify?

Mucormycosis 

Predisposing factors:

• Transplant recipients
• Uncontrolled diabetes mellitus
• Patients with hematological malignancies
• Immunosuppressed patients
• People living with HIV (PLHIV)

HOW TO IDENTIFY MUCORMYCOSIS:

Broad, aseptate fungal hyphae, branching at 90 degree.
Angioinvasion is frequently seen, leading to thrombosis of vessels and tissue infarction & necrosis.
Mucor is always seen as a basophilic "glassy" structure on H&E staining.

Pic shows fungal hyphae with right angled branching.

PAS and Silver Methanamine stain highlight the fungal hyphae.

Pic: PAS stain

Silver methanamine: Arrow points to the blood vessel, fungal hyphae are seen infiltrating the wall. 

DIFFERENTIAL DIAGNOSIS:
ASPERGILLUS:
Slender, septate hyphae with acute angle branching.


Note: Candida species is often seen with Mucor and Aspergillus.

Helicobacter pylori - More than half of world's population is affected, including you and me probably!!!

Helicobacter pylori

Helicobacter pylori causes the following:

1. Gastritis

2. Gastric ulcers

3. MALToma

4. Gastric carcinoma.

How do we identify H.pylori gastritis?

Many of us would have been taught to look for H.pylori organisms in a gastric biopsy with neutrophils (foveolitis/ foveolar abscess/ lamina propria infiltrates).

This is true!!!..

However, H.pylori is the most common type of CHRONIC GASTRITIS.

Presence of neutrophils only signifies active inflammation and likely presence of organisms in the biopsy.

Signs of H.pylori gastritis:

• Loss of mucin in the surface epithelium and epithelial damage leading to irregularity of the surface.
• Chronic inflammation in the lamina propria with lymphoid aggregates and plasma cells.

How do they look?

H.pylori are 2-4um curved structures.

Where to find them?

• Surface mucin
• Adherent to surface foveolar cells
• Within the foveolar pits

In figure, green circles - indicate plasma cells.
Curved organisms seen within the red circles - Helicobacter pylori.


Differential diagnosis for H.pylori:
Helicobacter heilmannii - twice as long as H.pylori and has 5-7 spirals.

Mönckeberg medial calcific sclerosis - An interesting finding!!

• First described by Johann Georg Monckeberg.
• It occurs most often in patients >50 years of age.
• Calcium deposits are seen in the muscular wall (media) of blood vessels.

• Results in thickening of the arterial wall and loss of elasticity.
• Does not have any serious pathologic consequence, since the lumen is patent.

In figure, arrow points to purple fragmented deposits that represent calcium.

The special stain that would highlight calcium is Von Kossa (stains the deposits black).

"Are You Afraid Of Monster Cells?" - Seminal Vesicle

Seminal vesicle

• Tall columnar epithelial cell lining with a layer of basal cells.
• Presence of golden brown refractile granules in the cytoplasm - LIPOFUSCIN.
• Lipofuscin - Also found in the ampulla of vas deferens and prostatic portion of ejaculatory ducts.

Important and an unusual feature: Presence of MONSTER CELLS - Cells with enlarged, hyperchromatic, irregularly shaped nuclei.

• Do not interpret these cells as malignant cells!!!
• May also be seen in the ampulla of vas deferens.

In figure, arrow points to the pigment; circle points to the MONSTER CELLS.

Arrow - MONSTER CELLS.

It is important to recognise seminal vesicle epithelium for two reasons:

1. Infiltration of seminal vesicle epithelium by prostatic carcinoma (pT3b).

2. To avoid misinterpretation of the seminal vesicle cells (monster cells) as malignant cells in core biopsies of prostate.

Why is identifying ganglion cells important?

Ganglion cells are absent in Hirschsprung disease (also called aganglionic megacolon).

Anatomy:
There are two neural plexus in the intestine - Submucosal (Meissner's) and myenteric (Auerbach's).

Submucosal (Meissner's) plexus - Present just beneath the muscularis mucosa.

In figure, red arrow --> Muscularis mucosa, blue arrow --> muscularis propria.
Space between the two (green line) --> submucosa; Yellow circle --> Submucosal plexus of ganglion cells.


Myenteric (Auerbach's) plexus - Present inbetween the two muscular layers of the bowel wall.

In figure, arrow --> neuronal processes
Circle --> Ganglion cell clusters

Important points:

• Ganglion cells are often associated with neuronal processes and Schwann cells.
• These interconnect and create a neural network throughout the submucosal  layer. 

• Often occur in clusters and may mimic giant cells, epithelioid cells or granulomas.

                               In figure, arrow --> neuronal processes, circle --> ganglion cells.

Diagnosis of Hirschsprung disease:
Absence of ganglion cells in the submucosal and the myenteric plexus.

Other features in favour of Hirschsprung's disease:
Hypertrophy of nerve bundles.
Hypertrophy of muscularis mucosae.