Pathology | Master Of Medicine

Category Archives: Pathology

Wilms tumour and associated syndromes

Wilms tumour

  1. Also known as nephroblastoma.
  2. Wilms tumour is the most common primary renal tumour in children.
  3. Usually wilms tumour is a solitary,well circumscribed lesion,but 10% is bilateral or multicentric.
  4. Triphasic combination of epithelial,stromal and blastemal elements.
  5. 5% show anaplasia associated with underlying P53 mutation and unresponsive to chemotherapy.
  6. Nephrogenic cell rests- High correlation with Wilms tumour in contralateral kidney.

Syndromes associated with wilms tumour

WAGR syndrome

  1. Wilms tumour
  2. Aniridia
  3. Genital abnormalities
  4. Mental retardation

Denys Drash Syndrome

  1. Gonadal dysgenesis(Male pseudohermaphroditism)
  2. Renal abnormalities

Beckwith Weidman syndrome

  1. Organomegaly
  2. Hemihypertrophy
  3. Renal medullary cysts
  4. Hepatoblastoma
  5. Adrenal cortical tumour
  6. Rhabdomyosarcoma
  7. Pancreatic tumour

Metastatic calification Vs Dystrophic calcification

Transmission electron microscope image of a th...

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Metastatic Calcification

  1. Due to deranged Calcium metabolism
  2. Increased calcium concentration in serum
  3. Mitochondria are the organelle first involved
  4. Alkaline PH favours precipitation of calcium salts

Sites involved in metastatic calcification are:

  1. Alveolar wall of lungs(Most common site)
  2. Basement membrane and tubular lamina of kidneys
  3. Interstitial tissue of gastric mucosa
  4. Systemic arteries
  5. Pulmonary veins
  6. Cornea and conjunctiva
  7. Synovium of joint
  8. Tendons

Dystrophic calcification

  1. Macroscopic deposition of Calcium salts in injured tissues
  2. Extracellular deposition of calcium
  3. Denatured proteins and dead tissue bind Phophate irreversibly
  4. Phosphate reacts with calcium and gets precipitated as Calcium Phosphate

Sites Involved

  1. Tubercular lymphnodes
  2. Mitral /Aortic valves in Rheumatic fever
  3. Atherosclerosis of arteries
  4. Breast tissue

Adenoid cystic carcinoma

  • Adenoid cystic carcinoma is also called cylindroma .
  • Constitute 10% of all salivary neoplasm
  • 65% of minor salivary gland tumours are malignant, of them 40% are adenoid cystic carcinomas.
  • Most common malignant tumour of minor salivary glands
  • Seen equally in males and females in 6th decade of life
  • Characterized by perineural spread and may lead to facial N palsy
  • Distant metastasis to lungs via hematogenous route.

Three histological types:

  1. Tubular
  2. Cribriform
  3. Solid


Nuclear and cytoplasmic inclusion bodies.

Intracytoplasmic Inclusion bodies

  1. Negri bodies – Rabies
  2. Guarneiri bodies – Vaccinia
  3. Bollinger bodies – Fowlpox
  4. Molluscum bodies -Molluscum Contagiosum
  5. Poschen bodies- Small Pox

Nuclear inclusion bodies

  1. Cowdry type A – Herpes virus, yellow fever virus.
  2. Cowdry type B- Adenovirus.

Microscopic appearances of RBC’s in specific diseases

Examination of peripheral smear often provides valuable clues for diagnosis of specific disease conditions. Appearances of RBC’s on peripheral smear can be useful in diagnosing conditions listed below


  1. Autoimmuune hemolysis
  2. Hereditary spherocytosis
  3. Post splenectomy
  4. DIC
  5. Clostridium Welchii septicemia
  6. Burns

Target cells

  1. Liver disease
  2. Post splenectomy
  3. Thalassemia
  4. Hb C disease

Howell Jolly bodies

  1. Megaloblastic anemia
  2. Post splenectomy

Basophilic stippling

  1. Lead poisoning
  2. 5′ nucleotidase
  3. Thalassemia
  4. Myelodysplasia
  5. Aplastic anemia


  1. Chronic liver disease

Burr cells

  1. Uremia


  1. Alcoholism

HLA’s associated with specific diseases


HLA types associated with various diseases is a hot favorite question of many PG exams. So pooling all these HLA types and the diseases associated with them seemed to be a good idea. Given below is a list of most frequently asked HLA types.

Diseases and associated HLA

  • Multiple sclerosis- HLA DR2
    Narcolepsy- HLA DR2
    Goodpasture’s syndrome- HLA DR2
    Sjogrens- HLA DR3
    Dermatitis herpetiformis- HLA DR3
    Celiac disease- HLA DR3
    Rheumatoid arthritis- HLA DR4
    Behcets disease – HLA B5
    Congenital adrenal hyperplasia- HLA B47
    SLE- HLA DR2,DR3
    Type 1 Diabetes – HLA DR2,DR3,DR4
    Hyperthyroidism – HLA B8,DR3
    Myasthenia gravis- HLA B8,DR3
    Tuberculoid leprosy- HLA B8,DR3
    VKH syndrome- HLA DW 15,DR4

Conditions associated with HLA B27

  1. Ankylosing spondylitis
  2. Psoriatic arthritis
  3. Reiters syndrome
  4. Reactive arthritis(Yersinia, salmonella,gonococci)
  5. JRA(pauci articular)

Multiple myeloma

Durie and Salmon myeloma diagnostic criteria

Major criteria

  1. Plasmacytoma on tissue biopsy
  2. Bonemarrow plasmacytosis with 30% plasma cells
  3. Monoclonal globulin spike(M spike) on Serum protein electrophoresis(SPEP):IgG>3.5g%,IgA>2g%,light chain excretion on UPEP>=1g/24hr in absence of amyloidosis

Minor criteria

  1. Bonemarrow plasmacytosis with 10-30% plasma cells
  2. Monoclonal globulin spike present, but lower than inĀ  major criteria
  3. Lytic bone lesions
  4. IgM>50mg/dl,IgA>100mg/dl or IgG>600mg/dl

Diagnosis of MM requires 1 major+1 minor or 3 minor that must include both 1st and 2nd minor criteria

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