Category Archives: Pathology

Pathogenesis of TB

Pathogenesis of TB
Droplet inhalation is the primary mode of infection
Infection by drinking milk contaminated with Mycobacterium bovis is now rare in developed nations
M. avium-intracellulare, are much less virulent than M. tuberculosis and rarely cause disease in immunocompetent individuals
The bacilli are obligate aerobes whose slow growth is retarded by a pH lower than 6.5, hence not found in the center of granuloma
caseating granulomas and cavitation, are the result of the destructive tissue hypersensitivity that is part and parcel of the host immune response
Pulmonary alveolar macrophages engulf the bacteria
endosomal manipulation by the bacteria in the macrophaghe impairs phagolysosome formation, allowing unhindered mycobacterial proliferation
bacillary proliferation within the pulmonary alveolar macrophages and airspaces, with resulting bacteremia and seeding of multiple sites
development of cell-mediated immunity occurs approximately 3 weeks after exposure
Macrophages carry bacilli to the draining lymph nodes and are presented in a MHCII by dendritic cell/macrophages( APCs) to CD4+ T cells.
IFN-γ released by the CD4+ T cells of the TH1 subset is crucial in activating macrophages.

Top Pathology resources and websites مواقع باثولوجي

 Reference Websites:

  1. Pathology Outlines [comprehensive “online textbook” of pathology]
  2. PathCONSULT (Elsevier) [broad “online textbook” of pathology]
  3. The Knowledge Hub (USCAP) [collected educational materials form past USCAP conferences]
  4. CAP Cancer Reporting Checklists (College of American Pathologists)
  5. University of Virginia Pathology Tutorials [GU, gyne, hemepath, parasitology]
  6. Cancer Management Guidelines (BC Cancer Institute)
  7. eMedicine Pathology Articles [virtual textbook by entity]


  1. “Medical School Pathology” (John Minarcik)
  1. General Pathology Lectures [based on Robbin’s first 10 chapters] [Youtube link]
  2. Corresponding “Multiheader” Slide-Based Histopathology Videos
  1. YouTube Pathology Lectures (based on the first 10 chapters of Robbins)
  2. The Basic Medical Pathology Series (NLM, UAB)
  3. The Online Interactive Pathology Laboratory (IPLAB) (UAB) [designed to compliment Robbins textbook]
  4. Basic Pathology Concepts Tutorial (JHU)

Unknown Case Conferences (weekly, monthly):

  1. Surgical Pathology Online Unknown Cases (JHU) [new cases weekly; free registration required]
  2. GI & Liver Pathology Case Conference (JHU) [2-4 new cases per month]
  3. Case of the Week ( [archived cases by category or diagnosis]
  4. Online Case Studies (U Pittsburgh) [new case weekly]
  5. Division of Cytopathology Interesting Case Conference (JHU) [>100 old cases; free registration required]
  6. Cytology Case of the Month ( archived cases
  7. PathMD AP/CP Board Review [monthly exam practice questions; question archiveanswer archive,image archive]
  8. Case of the month (College of American Pathologists)
  9. Image of the week (Pathology Network, Lippincott)
  10. Enjoy pathology (U Colorado professor) [case collections in surg path, dermpath, and hemepath]

Pathology Atlases

  1. WebPathology ( [particularly strong in urologic/gynecologic/breast images]
  2. PathPedia e-Atlas ( [histology and histopathology]
  3. SurgPath4U [library of entities by organ site with diagnostic feature walkthroughs]

Virtual Slide Libraries:

  1. USCAP Virtual Slide Box (USCAP) [with virtual microscopy]
  2. Leeds Virtual Slide Library [with virtual microscopy] <— hint: just select an organ system and click         “search”
  3. Virtual Slidebox of Histopathology (U of Iowa) [virtual slides]
  4. PathXchange ( [community-contributed cases]
  5. Pathology Pics [posted photomicrographs, quick practice cases, question of the day]
  6. Epathologies “Pathology Quizzes” (St Joseph University)
  7. Jaun Rosai’s Collection of Surgical Pathology Seminars ( [virtual slides]
  8. Youtube Histopathology (John Minarcik)
  1. AdrenalAppendixBoneBladderBone MarrowBrainBreastCervixColonEsophagus,EyeFallopian TubeGallbladderHeartJointKidneyLiverLungLymph NodeMouth,MuscleNeckNoseOvaryPancreasParathyroidPenisPituitaryProstateSalivary Gland,SkinSmall IntestineSoft TissueSpleenStomachTestisThymusThyroidUreter,UterusVaginaVesselsVulva

Textbooks for Download:

  1. IARC Publications (International Agency for Research on Cancer); Includes:
  1. WHO Classification of Tumors: Pathology and Genetics of Tumour of the Digestive System
  2. WHO Classification of Tumors: Pathology and Genetics of Tumours of Soft Tissue and Bone
  3. WHO Classification of Tumors: Pathology and Genetics of Tumours of the Skin
  4. WHO Classification of Tumors: Pathology and Genetics of Tumours of the Urinary System and Male Genital Organs
  5. WHO Classification of Tumors: Pathology and Genetics of Head and Neck Tumours
  6. WHO Classification of Tumors: Pathology and Genetics of Tumours of the Lung, Pleura, Thymus, and Heart


  1. Immunohistochemical Vade Mecum (Dr. P Bishop) [IHC stain reference]
  2. NordIQ Epitope Descriptions (not for profit)
  3. Immunohistochemistry FAQ [textbook companion]
  4. [ Stains A-E | Stains F-Z and Cell Cycle | CD Markers ]
  5. Antibody and Beyond (
  6. Immunohistochemistry World (