Characteristic Features of Tumours
1. Squamous Cell Carcinoma (SCC)
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- Features:
- Keratin (Acellular),
- Stratified squamous epithelium,
- Nests of tumour cells.
- High Power:
- Desmosomes (interdigitating bridges) seen.
- Types:
Well Differentiated | Keratin Pearls (KPs), Desmosomes. | ã…¤ |
Moderately Differentiated | Individual cell keratinization | ã…¤ |
Poorly Differentiated | No KPs. | ã…¤ |
- IHC markers:
- Cytokeratin (CK),
- P63 (Newer).
2. Adenocarcinoma
- Glands lined by malignant cells.
- Neoplastic cell features:
- Hyperchromatic nuclei
- High N/C ratio
- Prominent nucleoli
- Loss of polarity
- Epithelial lining: Cuboidal/columnar.
3. Papillary Carcinoma
- True papillae:Â Fibrovascular core present.
- Pseudopapillae:Â No fibrovascular core.
Commonly seen sites:
- Kidney:Â
- Core: Foamy histiocytes.
- Thyroid:Â
- Core:
- Fibrovascular
- Orphan Annie eye
- Mnemonic:
- Dystrophin → Destroyed by Red Ali’s (Alizarin) black cash (black Kossa) → Dead ammumma (psammomma)
- news came on monkey (monke) media (tunica media) → ammumma died due to atherosclerosis (atheroma)
- Onion skinning, round pattern
- Mnemonic: PSM Squared
- Monckeberg's Sclerosis (CMD):
- Ca in tunica media (old age).
Feature | Details |
Foci of dystrophic calcification | • Dead parasite, bacteria, TB • Degenerating tissue • Atherosclerosis Seen in • Papillary RCC • Papillary carcinoma of thyroid • Mesothelioma • Meningioma • Serous cystadenoma of ovary • Prolactinoma • Somatostatinoma Mesa (mesothelioma) ulla serious (serous) men (meningioma) like Milk (prolactinoma) & pappam (PP) |
Stain for Calcium | Color | Mnemonic |
Von Kossa stain | Black/kala color | Calcium sounds like calcine → Von Kossa kala |
Alizarin Red S | Red color | Al for Alizarin |
- First Site of Calcium Deposition:
- Mitochondria
- Exception (kidney):Â Basement membrane.
Neuroendocrine Tumors
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- Pheochromocytoma
- Paraganglioma
- Carcinoid tumor
- Carotid body tumor
- Lyre sign on angiography : Splaying of carotids.
- Highly vascular tumor.
- Small cell carcinoma of lung
- Most functional Pancreatic tumor → Insulinoma
- Medullary Carcinoma Thyroid
Imaging
- Best → PET >> MRI
Microscopy:
- Nesting pattern (Zellballen pattern)
- Cells within a Nest
- Fibrous septa (Lined by flattened sustentacular cells)
- Speckled chromatin (Salt and pepper chromatin)
Two types of cells within nests:
- Chief cells:
- Main neuroendocrine cellsÂ
- Neuroendocrine markers:
- Synaptophysin
- Chromogranin
- Bombesin
- CD56, CD57,
- NSE
- New marker for NET:
- INSM1Â (nuclear)
- Mnemonic:
- NET (NET) ittu pidichu → Bombitt () sincheyth () 56, 57 () vayssulla alkkare kollunnu → To Nicely (NSE) End Colorful (chromogranin) Insan (INSM1)
- Sustentacular cells:
- Supporting cells,
- S100 positive.
Electron Microscopy:
- Shows dense neurosecretory granules (black granules).
Mnemonic:
- Selven (Zellballen pattern) Chrome (Feochromo) use cheythapo Net (NET) poi
- Chief (chief cells) avane suspend (sustentacular cells) cheyythu 100 (s100) divasathekk
- Para vachatha (Paraganglioma)
- Pullikk Small (Small cell) car (Carcinoid, Carotid body) ee ollu
- Pullikk oru PET (PET) um ind
5. Small Round Blue Cell Tumours
- Features: Small, round, blue cells, scanty cytoplasm.
- Rosettes:
- True Rosette:Â
- Empty lumen
- Flexner wintersteiner rosette
- e.g., Retinoblastoma
- False/Pseudo Rosette:Â
- Lumen filled with pink material
- Homer wright rosette
- Homer Wright rosettes or pseudomedullary rosettes
- Center → filled
- Mnemonic: Psudo friends → hide something inside their heart
- Flexner Winterstener Rosette
- Center → Pale or white
- Mnemonic: True friends wants what is good for you → heart (centre) is pure white
- Found in small round blue cell tumor
- Homer-Wright → pseudo rosettes.
- Mnemonic: MEN () R () Wright () and Men are Pseudo, Men are Blast
- Medulloblastoma
- Ewings/Ependymoma
- Neuroblastoma
- Retinoblastoma
- (Both rosettes → seen in Retinoblastoma).
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- For small round uniform blue cells: → Starry sky pattern on biopsy
- Mnemonic: BLUE → BLRE
- Rhabdomyosarcoma
- Ewing's sarcoma/PNET
- Lymphoma
- Blastemal tumour group
- Neuroblastoma,
- Retinoblastoma,
- Hepatoblastoma,
- Medulloblastoma,
- Nephroblastoma /Wilms tumour
6. Mucinous Tumour
- Mechanism:
- Mucin production
- Extracellular mucin.
- Intracellular mucin.
- Nucleus pushed to periphery.
- Seen in: Stomach cancer.
- Krukenberg's tumour:Â
- Diffuse gastric cancer metastasizing to ovary.
- Signet ring cell:Â
- Nucleus pushed to periphery by mucin.
CDH gene (E-cadherin):
- Chromosome 16
- "Glue" for cell-to-cell connection.
Loss/mutation
- Mnemonic: Kadich (CDH) → Breastlum Vyarilum
- "Golu" tumors/Kadicha tumors
- Diffuse Gastric Cancer
- Lobular Carcinoma Breast
- Indian File/Single File Pattern
- Mnemonic: File (Indian file) of Breast Ca patients
- Claudin low → EMT positive breast cancer
Lauren's Classification | Intestinal Lauren's Classification | Diffuse Lauren's Classification |
Epidemiological | Environmental | Familial |
Pathology | Gastric atrophy, intestinal metaplasia | Blood Group A |
Sex | m > F | F > M |
Age | ↑ Incidence with ↑Age | Younger age |
Morphology | Gland formation Round glands | Poorly differentiated |
Cell Type | ㅤ | • Gross: Linitis plastica ("leather bottle appearance"). • Microscopy: Signet ring cells. |
Genetics | APC gene mutations, Microsatellite instability p53, p16 inactivation | Loss of E-cadherin (↓ E-cadherin) p53, p16 inactivation |
Invasion | Hematogenous spread | Transmural/Lymphatic spread |
- Krukenberg tumor
- Stomach > Breast/ Colon
- Signet Ring Cells
- Retrograde lymphatic spread
NOTE: Miscellaneous one liners
7. Clear Cell Carcinoma
- Features: Clear cells.
- Clearing due to:Â
- Glycogen (PAS +ve),
- Fat (Oil red O +ve),
- Water.
- Seen in:
- Cancer of Kidney and Vagina (DES daughters)
Different Patterns in Cancers
Cribriform Pattern:
- Appearance: Sieve/swiss cheese/cookie cutter.
- Seen in:
- Cribriform DCIS
- Adenoid cystic Ca
- Prostatic Carcinoma → Gleason Pattern 4
- Crib (Cribriform) nte adiyil (Adenocystic Ca) Duckum (Ducatal Ca insitu) Rose (Prostate) um Swiss () cheesum () cookieum ()
Indian File/Single File Pattern:
- Seen in: Invasive lobular Ca breast (Loss of E Cadherin).
Mnemonic: LIC (ILC → Inv Lob C) officil File () eduthond varunna pennine kadich (CDH)
Owl's Eye Appearance:
- Reed Sternberg cells:
- Hodgkin's lymphoma
- Binucleated with prominent eosinophilic nucleoli
- Cytomegalovirus inclusions:
- Basophilic.
Fried Egg Appearance:
- Seen in:
- Oligodendroglioma
- Hairy cell leukemia (Bone marrow biopsy).
Coffee Bean Nuclei:
- Seen in:
- Papillary Ca thyroid
- LCH (Langerhans Cell Histiocytosis)
- Brenner's tumour
- Chondroblastoma
- Granulosa cell tumour
- Mnemonic: bru cofeee, papa, granny, lan phone
- Pappa (Papi) Lanphonil (Lang C H) vilichapo, granny (Granulosa) was drinking bru (Brunner) coffee (Chondroblastoma)
Lepidic Cells in pathology
- Bronchoalveolar carcinoma → Adenocarcinoma In situ
- Cardiac myxoma
- Mnemonic: Leopard is back (BAC → Bronchoalveolar Ca) in car (Cardiac myxoma)
3 Massons in pathology
- Masson bodies
- BOOP
- Bronchiolitis Obliterans organising pneumonia OR
- Cryptogenic organising pneumonia
- Masson bodies
- Masson Fontana stain
- for melanin
- Masson trichrome stain
- for collagen
Swyer James Mcleod syndrome
- Post bronchiolitis obliterans.
- decreased vessel markings
- Mnemonic: Mcleod syndrome → Makkalkk varunna syndrome
Onion Skin Appearance:
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- Mnemonic:
- Onion → PSC exam
- PSC (Primary Sclerosing) kk padikan Sleep (SLE, Spleen) kalanj Tea (Tay) kudich BP (HTN) kuutti → Kidappilayi (CIDP)
- but Wings (ewing) vannu
- Lysosomes with onion-skin appearance - Tay sach’s
- Paccinian corpuscles
- Seen in:
- Chronic inflammatory demyelinating polyneuropathy (Biopsy)
- Primary sclerosing cholangitis (Biopsy)
- SLE, spleen (Gross)
- Ewing's sarcoma (X-ray)
- Tay sach's disease (Electron microscopy)
- Malignant hypertension (Biopsy).
Benign Hypertension
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Associated Condition | Benign Hypertension | Malignant Hypertension |
Feature | Benign Nephrosclerosis | Malignant Nephrosclerosis |
Histological Finding | Pink, homogenous hyaline thickening of vessel wall | Concentric laminated thickening of vessel wall |
Appearance/Result | Luminal narrowing | Onion skin appearance |
Glomeruloid Bodies:
- Features: Concentric tumour cells, blood vessels.
- Seen in:
- Glioblastoma multiforme
- Grade 4 astrocytoma
- Yolk sac tumour
- Schiller Duval body
- Mnemonic: Chill the egg (Yolk sac)
Koilocytes:
- Features:
- Large cell, raisinoid nucleus, perinuclear clearing.
- Seen in:
- HPV infection (Testis, cervix).
- Mnemonic: Koilocytes → Coitus → Testis and cervix → HPV
Hurthle Cells/Oncocytes (Oncocytic Changes):
- Associated: Lymphocytic infiltrate.
- AKA Oxyphil/ashkenazi cells
- Cells with abundant eosinophilic granular cytoplasm
- Excessive mitochondria
- Seen in:
- Hashimoto's thyroiditis
- Oncocytoma (Benign)
- Mnemonic:
- Oncall (oncocytoma) Hashim (Hashimotos) should hurry (hurthle) bcz Nazi (ashkanazi) needs Oxygen (oxyphil)
Intranuclear Inclusion Bodies:
- Cowdry type A
- Seen in:
- Yellow fever: Torres bodies.
- Herpes Simplex: Lipschultz.
- Mnemonic: Tore Yellow shirt → Kiss Her Lips
- Cowdry type B
- Seen in:
- Adenovirus.
- Poliovirus.
- Mnemonic: Adipoli breast
Both intracytoplasmic + intranuclear forms:
- CMV (Cytomegalovirus)
- Shows: Owl eye appearance.
- Measles
- Shows: Warthin Finkeldey giant cells.
- large grapelike clusters
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