Histology Basics Flashcards
Features of Acute Inflammation (5)
● Vascular congestion
● Edema
● Fibrinous exudate
● Tissue damage and/or necrosis
● Neutrophils (or polymorphonuclear leukocytes, often shortened to “polys”)
Features of Chronic Inflammation
● Increased vascularity and/or fibrosis (attempts to heal)
● Tissue destruction or obliteration of normal structures
● Lymphocytes, macrophages*, plasma cells, eosinophils
Acanthosis
thickening of the epithelium, usually referring to a keratinized epidermis.
Hyperkeratosis
too much keratin, which sits on the epithelial surface in a thick pink layer, often accompanied by parakeratosis.
Orthokeratosis
“normal” anucleate keratin, found on the skin, with a basket weave pattern.
Parakeratosis
the retention of small pyknotic nuclei in surface keratin
Papilloma
exophytic growth of finger-like, arborizing projections with fibrovascular cores, lined by squamous epithelium
Pseudoepitheliomatous hyperplasia:
a benign reactive condition that simulates invasive squamous cell carcinoma. It has a very characteristic look, as though someone dragged the epithelium down into the stroma with a toothpick, like marbling a cake. The individual nuclei should look reactive, not dysplastic. There should not be deep keratinization. Granular cell tumors are notorious for provoking an intense pseudoepitheliomatous reaction.
Verrucous
warty; an exophytic growth pattern with prominent hyperkeratosis and an appearance described as “church spire” (pointy projections) or “cauliflower” (rounded projections).
Alveolar
resembling alveoli or little cells, sacs, or nests; Nested—there is structure to the lesion but no glands or ducts
Basaloid:
resembling basal cell carcinoma; A blue, nested tumor (often poorly differentiated squamous) with tightly packed nuclei and palisading
Biphasic
having components of two cell lineages; Spindled cells with islands of epithelial cells or glands
Cribriform
perforated, like a colander; Crisp round holes within a glandular structure
Chicken wire
branching, anastamosing network of vessels
Discohesive
falling apart into single cells; No common borders among cells
Epithelioid:
composed of round to oval cells with abundant cytoplasm; Cells look plump and have clear cell borders; the opposite of sarcomatoid
Fascicular:
composed of fascicles Bundles of elongated, spindly cells streaming in parallel arrays
Glandular:
forming gland structures with lumens True glands should have polarized cells radiating around a lumen
Festoon-like/Garland-like
undulating appearance
Filigree-like
complex, interwining threads
Geographic necrosis
large confluent areas of necrosis with an irregular outline
Glomeruloid:
resembling the glomerulus; A coiled tangle of vessels, capillaries, or glands
Herringbone:
resembling a pattern of tweed fabric; A variant of fascicular that shows bundles alternating in a zigzag array
Hobnailed:
resembling a large-headed nail once used in shoes; Epithelial or endothelial cells that round up and protrude into the lumen as little humps
“Indian file”:
cells infiltrating through the tissue in single-file lines; Lines may be only three to four cells long and run parallel to stromal planes
Microcystic:
scattered small cystic spaces that are not ducts, tubules, or glands; Microcysts lack polarized epithelial linings and are haphazard; nuclei touch the lumen
Micropapillary:
papillary-shaped epithelial projections without true fibrovascular cores; Can have a medusa-head appearance (serous carcinoma) or lollipop projections into a duct
Insular
large nests, “island”
Lepidic
Scale-like
Lobular
smooth contour, resembling a normal anatomic unit
Nested
Packets of cells resembling nests, separated by stroma
Pagetoid spread:
single malignant cells scattered throughout a benign epidermis Cells standing out at low power as not belonging in the epithelium
nodular
discrete groups of cells with a rounded countour, larger than nests
Palisading:
resembling a fence made of sharp stakes; Parallel arrays of nuclei catching your eye at low power as a dark border
Papillary:
an exophytic growth pattern with fibrovascular cores supporting proliferative epithelium; Cauliflower- or coral-shaped structures with branching fibrovascular cores
Polarized:
epithelial cells that have a uniform nuclear position, either apical (lumen side) or basal (basement membrane side); Polarized cells surrounding a true lumen should show a distinct ring of cytoplasm surrounding the lumen, if the nuclei are basal
Pseudopapillary:
a papillary pattern caused by cell die-off in between fibrovascular septa; Looks papillary but there is evidence of solid or nested growth in some areas
Reticular:
resembling a network or netlike array Microcystic or honeycomb appearance
Rosettes:
a group of non-epithelial cells that are clustered around a common center; Pseudorosettes are rosettes around a vessel; true rosettes surround a lumen or a fibrillary core
Homer Wright rosettes
Perivascular pseudorosettes:
Luminal rosettes
Sarcomatoid:
resembling a sarcoma, but not one Sheets or bundles of tumor cells without epithelial structures or clear cell borders
Staghorn vessels:
gaping, branching vessels with thin walls, scattered throughout a lesion; Vessels should strike you as prominent at low power; the shape is unusual, and the walls are disproportionately
Storiform:
having a cartwheel pattern—spindle cells with elongated nuclei radiating from a center point; A cellular spindled lesion with short whorls of cells as opposed to long parallel fascicles
Tissue culture pattern:
a loose aggregate of stellate (star-shaped) cells; Cells have delicate tentacles of cytoplasm
Syncytial:
having apparent cytoplasmic continuity between adjacent cells; Looks like a collection of nuclei without recognizable cell borders
Trabecular:
cord-like arrays separated by fibrous septa; Long nests and cords of cell groups
Villous
Fingerlike projections (GI)
Whorled
Cells in a circular arrangement
Coagulative necrosis
Cells appear mummified; architecture is preserved, but there is no basophilia or cell detail
Caseating necrosis
Total loss of cellular structure and architecture; basically degenerates into pink soup
Fibrinoid necrosis
Vessels with replacement of wall by pink amorphous material
Fat necrosis
Grossly hard and chalky white; microscopically the fat cells are disrupted and collapsed, with foamy macrophages and giant cells
Necrobiosis or gangrenous necrosis
Has a granular and blue look, with lots of fibrin deposition; loss of cellular and architectural detail
Amphophilic:
having an affinity for both acid and basic dyes Has a unique color character, almost an iridescent purple that is hard to capture on film
Coffee bean-like
Longitudinal Groove
Fried egg-like cell
cells with a perfectly rounded nucleus surrounded by a clear halo or pale cytoplasm
Grooved
containing an indentation or a cleft
Foamy macrophages:
macrophages (histiocytes) stuffed with lipid Macrophages have a small dark eccentric nucleus; the lipid vacuoles
Keratinized:
keratin-producing Keratin has a very pink and dense appearance on H&E stain
Oncocytic:
large cells with cytoplasm that is granular and eosinophilic due to the presence of abundant mitochondria; usually cytologically bland (uniform small dense nuclei) and look pink on H&E, mahogany on gross examination
Plasmacytoid: l
Round cells with abundant cytoplasm and an eccentric round nucleus
Rhabdoid:
refers to a specific malignant tumor that resembles rhabdomyosarcoma or used to describe a tumor with similar histology; Large tumor cells with eccentric nuclei, prominent nucleoli, and globules of pink cytoplasm
Ground Glass
optical clearing of nuclei
Leukocytoclastic
fragmentation of neutrophils
Orphan Annie eyes-like (nucleus
optical clearing of nuclei
Physaliphorous
Bubbles or vacuoles
Polygonal
tumor cells with sharp squared cell membranes
Reniform
kidney shaped, indented, containing a groove
Salt and pepper chromatin
Finely speckeld chromatin evenly distributed within the nucleus
Signet ring:
having the shape of a jeweled ring, with a flattened nucleus compressed by a cytoplasm stuffed with mucin; Can be very hard to see on low power; on high power, the cell is a droplet of mucin with a faint cell wall and a nucleus pushed to one side
Stellate
Star-shaped
Molding:
nuclei that press together and indent each other due to the near absence of cytoplasm; Has a mosaic appearance and usually seen in conjunction with small dense blue nuclei
Vesicular:
a nucleus in open phase, in which the chromatin is expanded (as opposed to compact and condensed) A nucleus that is swollen and distorted by apparent bubbles in the chromatin
Cherry red:
implies a malignantlooking nucleolus; An enlarged, solid nucleolus with a refractile red tinge due to increased protein content
Langhans-type giant cells
peripheral semi-circular nuclei, “horse-shoe”
Foreign body-type giant cells
haphazardly arranged nuceli, often aggregating towards the center of a cell
Touton giant cells
full ring of nuclei with eosinophilic cytoplasm centrally and foamy cytoplasm peripherally
Floret cell
wreath of hyperchromatic peripheral nuceli
Osteoclast-like giant cell
mutliple bland central nuceli, ruffled cell membrane
Tumor giant cells
pleomorphic cytology, seen in anaplastic carcinomas, and high-grade sarcomas
Hyaline:
clear, transparent, homogeneous Glassy-pink appearance
Fibrotic/sclerotic:
replaced by collagen (fibrosis); Collagen is pink and opaque on H&E and usually streams in parallel fibers
Mucinous (colloid)
slimy viscous materials that appears purple and stringy on H&E
Myxoid:
resembling mucus, but usually associated with a soft tissue lesion and hyaluronic acid; Appears as a faint pink to bluish-gray background, with a stringy mucous look
Sclerotic
“thickening or hardening” of nonspecific etiology - microscopic fibrosis/collagen deposition, macroscopic plaques, vessel hardening
