Electron microscopy

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This article is a brief collection things electron microscopy. It is commonly abbreviated EM.

Fixation for EM is often done with glutaraldehyde.[1]

Ultrastructural findings

Glycogen

General

Seen in:

Ultrastructure

Appearance:

  • Cytoplasmic, electron dense, not bound by a membrane.

Tubuloreticular inclusions

Abbreviated TRIs.

General

Seen in:

Ultrastructure

Appearance:

  • Undulating tubules in the smooth ER, usu. perinuclear.[2]

Melanosomes

General

Seen in:

Ultrastructure

Appearance:

  • Membrane bound, sausage-like shape.

Image(s):

Neurosecretory granules

  • AKA dense-core granules.

General

Seen in:

Ultrastructure

Appearance:[4]

  • Round membrane bound, granular core.
  • Size: 100-400 nm.

Image(s):

Birbeck granules

General

Ultrastructure

Appearance:

  • Electron dense, cytoplasmic tennis racket-like body.

Image(s):

Tonofilaments

General

  • Found in epithelial cells.
  • Part of the cytoskeleton.
  • May be found in the epithelioid component of a biphasic synovial sarcoma.[5]

Ultrastructure

Features:

  • Filamentous structures at the cell periphery - vaguely resemble striated muscle.

Image(s):

Zymogen granules

General

Ultrastructure

Features:

  • Round structures ~0.5-1.5 μm.

Images:

Specific diagnoses

Malignant mesothelioma

Several EM features can be useful to distinguish mesothelioma from adenocarcinoma as per Warhol et al:[8]

  • Microvillous length -- longer in mesothelioma.
  • Quantity of intermediate filaments -- mesothelioma have more.

See also

References

  1. Prentø, P. (Nov 1995). "Glutaraldehyde for electron microscopy: a practical investigation of commercial glutaraldehydes and glutaraldehyde-storage conditions.". Histochem J 27 (11): 906-13. PMID 8787969.
  2. Stoltenburg-Didinger G, Genth E (June 2009). "[Dermatomyositis]" (in German). Z Rheumatol 68 (4): 287–94. doi:10.1007/s00393-008-0398-y. PMID 19330338.
  3. Gil-Moreno, A.; Garcia-Jiménez, A.; González-Bosquet, J.; Esteller, M.; Castellví-Vives, J.; Martínez Palones, JM.; Xercavins, J. (Mar 1997). "Merkel cell carcinoma of the vulva.". Gynecol Oncol 64 (3): 526-32. PMID 9062165.
  4. URL: http://www.pathologyimagesinc.com/emhandbook/diagn-organelles-section/organelle-pages/neuroendo-granules.html. Accessed on: 11 February 2011.
  5. Fisher, C. (Dec 1998). "Synovial sarcoma.". Ann Diagn Pathol 2 (6): 401-21. PMID 9930576.
  6. Gorelick, FS.; Otani, T. (Jul 1999). "Mechanisms of intracellular zymogen activation.". Baillieres Best Pract Res Clin Gastroenterol 13 (2): 227-40. PMID 11030603.
  7. URL: http://www3.mpibpc.mpg.de/groups/em/Gallery.htm. Accessed on: 1 June 2012.
  8. Warhol, MJ.; Hickey, WF.; Corson, JM. (Jun 1982). "Malignant mesothelioma: ultrastructural distinction from adenocarcinoma.". Am J Surg Pathol 6 (4): 307-14. PMID 6287872.

External links