Path findings/details Flashcards
Touton giant cell
ring of nuclei surrounded by a foamy ring of lipid
-assoc/w/xanthogranulomatous dz
(Juvenile X-linked xanthogranuloma, adult-onset xanthogranuloma, adult onset asthma, periocular xanthogranuloma, necrobiotic xanthogranuloma, Erdheim Chester dz)
Langhans giant cells
HORSESHOE shaped ring of nuceli around the cell
-assoc/w/GCA and sarcoidosis
Homer Wright rosettes
retinoblastoma, neuroblastoma, medulloblastoma of cerebellum
Psammoma bodies
found in many tumors, including ON meningioma, pituitary prolactinoma
Rosenthal fibers
degenerating eosinophilic filaments, found in ON gliomas and other astrocytomas.
Formalin
permeates at a rate of ~ 1 mm/hour. Since eye is ~24 mm in diameter, and the formalin needs to travel 12 mm from each surface to reach the center, it takes ~12 hours to fix a glove. Ideally the entire eye should be suspended in formalin for at least 12 hours prior to processing (usually > 24 hours).
Demonstrate the presence of iron
-Prussian blue stain or Perls test
von Kossa stain
- demonstrates the presence of calcium in tissues by staining calcium salts black (e.g. band keratopathy)
Masson Trichrome
stain corneal stroma (hyaline) deposits in granular dystrophy
Also see in Reis Buckler (Absent BM replaced with sawtooth pattern of fibrocellular tissue)
Collagen stains blue; hyaline stains red
RED ON BLUE
Alcian blue
classically used to stain the cornea stroma (mucopolysaccharide) deposits in macular dystrophy
Antoni A and Antoni B
two histological patterns that occur in schwannomas (aka neurilemomas)
schwannomas - benign peripheral nerve sheath tumors that may arise de novo or as part of NF1/NF2
Antoni A = COMPACT groups of spindle cells within a tumor. often contain “verocay bodies” stacked arrangements of elongated palisading nuceli alternating with anuclear zones containing cell processes
Antoni B = lose meshwork of tissue interspersed with cystic spaces. Can indicate histological degeneration within the tumor.
Gluaraldehyde
fixative = used for samples undergoing EM
Ethyl alcohol
fixative for cytologic preparations
Michel fixative
immunofluorescence specimens
How are eyes cut?
Most eyes are cut so that the pupil and optic nerve (“PO section”) are contained in the same section. For globes with intraocular tumors, the globe is cut so that the center of the tumor (as outlined by previous transillumination) is in the PO section.
frozen sections
Obtaining frozen sections for a tissue sample is an arduous and expensive process and should only be performed when appropriate. Valid indications for frozen sections includes: determining whether the margins are clear of tumor cells; providing fresh tissue for molecular genetics; to determine whether representative tissue has been biopsed for diagnosis; and to ensure tissue conservation (i.e. in the case of Moh’s surgery).
A surgeon is not supposed to order frozen sections and then proceed with the case before the results are obtained from the pathologist. Definitive diagnosis of a lesion requires permanent sections; i.e. it is inappropriate to produce a formal diagnosis with frozen sections alone.
Amyloid SECONDARY protein structure
composed of different proteins - final structure: beta pleated sheet with nonbranching fibrils (75-100 angstroms)
Amyloid deposits: composed of abnormal (mutated) forms of the protein “transthyretin”
% of K limbal stem cells that must be intact to replenish the K epi
25-33%
Average dioptric power of the cornea
43.25
Below what endothelial cell count would it be dangerous to do surgery?
1000 cells/mm^2
Acid-Fast / Ziehl-Neelson
Mycobacteria; Nocardia
Detects granular dystrophy Congo red Amyloid stains orange Detects lattice dystrophy Crystal violet Amyloid stains red-purple Detects lattice dystrophy Alcian blue Acid mucopolysaccaride (blue) Detects macular dystrophy Colloidal iron Acid mucopolysaccaride (blue) Detects macular dystrophy
Periodic acid-Schiff (PAS)
Basement membranes; fungi
Gomori’s methenamine silver
Fungi
Calcofluor white
Acanthamoeba; fungi
