Whipples disease | Anatomy2Medicine
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Whipples disease

    • Whipple disease
      • multivisceral

 

  • Tropheryma whippelii is causative organism (MCQ)

 

        • Gram-positive actinomycete
      • Why lymphadenopathy occur in Whipple disease
        • organism-laden macrophages accumulate within the small intestinal lamina propria and mesenteric lymph nodes, causing lymphatic obstruction. (MCQ)
      • Why lymphadenopathy occur in Whipple disease malabsorptive diarrhea occur in Whipple disease
        • malabsorptive diarrhea is due to impaired lymphatic transport. (MCQ)
      • The morphologic hallmark is a dense accumulation of distended, foamy macrophages in the small intestinal lamina propria (MCQ)

 

  • The macrophages contain periodic acid–Schiff (PAS)-positive, diastase-resistant granules that represent lysosomes stuffed with partially digested bacteria (MCQ)

 

      • Intact rod-shaped bacilli can also be identified by electron microscopy (MCQ)
      • Whipple disease vs intestinal tuberculosis (MCQ)
        • infiltrate of foamy macrophages is present in both
        • in both diseases the organisms are PAS-positive.
        • mycobacteria stain positively with acid-fast stain while T. whippelii do not.
      • Shows shaggy gross appearance to the mucosal surface. (MCQ)
        • Occurs due to  villous expansion caused by the dense macrophage infiltrate
      • Shows endoscopic detection of white to yellow mucosal plaques(MCQ)
        • Occurs due to lymphatic dilatation and mucosal lipid deposition
      • In Whipple disease, bacteria-laden macrophages can accumulate within mesenteric lymph nodes, synovial membranes of affected joints, cardiac valves, the brain
      • Clinical triad of Whipple disease (MCQ)

 

  • diarrhea,
  • weight loss,

 

        • malabsorption.

 

  • Extraintestinal symptoms

 

        • can exist for months or years before malabsorption

 

  • include arthritis, arthralgia, fever, lymphadenopathy, and neurologic, cardiac, or pulmonary disease.

 

 

Topic -Reversible Cell Injury

      • Reversible injury is the ability to heal without permanent damage
        • Hyperplasia is an increase in the number of cells
        • Hypertrophy is an increase in cell size.
        • Atrophy is a decrease in cell size.
        • Metaplasia is an alteration of cell differentiation.
        • Intracellular accumulations are an altered metabolism
      • Hyperplasia can be physiologic or pathologic.
        • Physiologic hyperplasia
          • Hormones may drive hyperplasia (MCQ)
            • pregnant uterus
            • lactating breast
          • Compensatory hyperplasia may occur with tissue damage
            • liver regeneration after partial hepatectomy
            • wound repair

 

  • Initiation of cell proliferation includes induction of transcription factors and cell cycle proteins.

 

        • Pathologic hyperplasia
          • a risk factor for neoplasia
          • causes
            • usually due to  excessive hormonal stimulation (eg, PCOD leading to excessive estrogen production), (MCQ)
            • effects of growth factors.

 

  • Hypertrophy

 

        • increase in the size of the cell
        • occur due to the synthesis of structural components rather than cellular swelling.
        • It is usually a physiologic process due to increased functional demands
        • placed on the cell
          • hypertrophy of striated muscles from weight lifting
          • cardiac myocyte hypertrophy secondary to systemic hypertension(MCQ)
      • Atrophy is the reduction of cell or organ size.
        • Physiologic atrophy
          • occurs during fetal development (eg, regression of the notochord)
          • occurs throughout life (eg, muscle).
        • Common causes of atrophy include:
          • Decreased workload or denervation (eg, paralysis).
          • Diminished blood supply (eg, atherosclerosis).
          • Inadequate nutrition (eg, marasmus “muscle wasting”).
          • Loss of hormone stimulation (eg, menopause).
          • Aging (build up of cellular waste and DNA damage).
          • Compression (eg, organ compression by expanding tumor).

 

  • Metaplasia
  • differentiation from one mature cell type to another (MCQ)

 

        • squamous metaplasia of glandular respiratory epithelium
        • an adaptive response to a hostile environment.

 

  • usually a change from glandular mucosa to keratin rich squamous mucosa as in squamous metaplasia of ciliated respiratory mucosa because of smoking(MCQ)

 

        • mitochondria rich oncocytic cells can form(MCQ)
          • apocrine change in breast
          • Hürthle change in thyroid
          • oncocytic change in the salivary glands
        • Barrett esophagus. (MCQ)
          • Metaplasia from squamous to glandular mucosa is unusual
          • a common consequence of chronic reflux esophagitis
        • mechanism is thought to arise from reprogramming of stem cells (reserve cells) from the basal layer (MCQ)
          • eg, squamous metaplasia at the cervical trans- formation zone).
        • Metaplasia increases the patient’s risk for carcinoma
          • lung cancer from smoking(MCQ)
          • esophageal cancer from reflux
      • Intracellular accumulations
        • represent metabolic derangement.
        • Steatosis (fatty change) (MCQ)
          • develops in the liver

 

  • seen in ethanol , diabetes mellitus, obesity, and pregnancy.

 

        • Atherosclerosis
        • Immunoglobulin produced in excess in chronically active plasma cells produce round red Russell bodies. (MCQ)

 

  • Lipofuscin (MCQ)

 

          • brown pigment
          • derived from lipid peroxidation (MCQ)
          • commonly seen in aged organs.

 

  • Melanin

 

        • dark brown pigment ). (MCQ)
        • made in skin, hair, and eye (iris and choroid layer)
      • Hemosiderin
      • a granular brown pigment composed of ferric oxide
      • result from the breakdown of hemoglobin
      • a sign of hemolysis, or disturbed iron metabolism (eg, hemochromatosis). (MCQ)