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
- Seen in Langerhans cell histiocytosis.
Ultrastructure
Appearance:
- Electron dense, cytoplasmic tennis racket-like body.
Image(s):
- Birbeck granules (photobucket.com).
- Usually... only the handle of the tennis racket is well seen.
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
- Seen in acinic cell carcinoma.
- Pancreas - acinar cell.[6]
Ultrastructure
Features:
- Round structures ~0.5-1.5 μm.
Images:
Specific diagnoses
Malignant mesothelioma
Main article: 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
- ↑ 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.
- ↑ 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.
- ↑ 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.
- ↑ URL: http://www.pathologyimagesinc.com/emhandbook/diagn-organelles-section/organelle-pages/neuroendo-granules.html. Accessed on: 11 February 2011.
- ↑ Fisher, C. (Dec 1998). "Synovial sarcoma.". Ann Diagn Pathol 2 (6): 401-21. PMID 9930576.
- ↑ Gorelick, FS.; Otani, T. (Jul 1999). "Mechanisms of intracellular zymogen activation.". Baillieres Best Pract Res Clin Gastroenterol 13 (2): 227-40. PMID 11030603.
- ↑ URL: http://www3.mpibpc.mpg.de/groups/em/Gallery.htm. Accessed on: 1 June 2012.
- ↑ Warhol, MJ.; Hickey, WF.; Corson, JM. (Jun 1982). "Malignant mesothelioma: ultrastructural distinction from adenocarcinoma.". Am J Surg Pathol 6 (4): 307-14. PMID 6287872.