Pathology dictionary for patients


December 20, 2023


The pathology dictionary is a collection of patient-friendly definitions for the most common terms and phrases used by pathologists in pathology reports. These definitions describe general concepts. Visit our Diagnosis Library to learn more about your diagnosis or read this article for an introduction to your pathology report. Need help? Contact us.

A B C D E F G H I J K L M N O P R S T U V W X Y Z

A

Abscess
Acanthosis
Acute inflammation
Addendum
Adenoma
Adenocarcinoma
Adenomyosis
Adenosquamous carcinoma
Adipose tissue
Adrenal gland
AE1/AE3
Amendment
Amorphous
Anaplastic
Anemia
Angioinvasion
Antral type mucosa
Antibody
Apocrine
Apocrine metaplasia
Apoptosis
Arteriovenous malformation (AVM)
Atrophic
Atrophy
Atypia
Atypical
Atypical mitotic figure
Atypical mitosis​

B

B cells
Ballooning hepatocyte
Basal cells
Basal lymphoplasmacytosis
Basaloid neoplasm
Basophils
Benign
Benign neoplasm
Biopsy
Blasts
Blastoid
Body type mucosa
BRAF
Breslow thickness

C

Calcification
Calcitonin
Carcinoma
Carcinoma in situ
Carcinoid
Cardiac type mucosa
Cautery artifact
CD19
CD20
CD3
CD30
CD34
CD45
CD5
CD68
CDX-2
Cholesterol cleft
Chronic inflammation
Chromatin
Chromogranin
Clark’s level
Colonic mucosa
Columnar mucosa
Cribriform
Crohn’s disease
Crypt abscess
Crypt distortion
Cryptitis
Cyclin D1
Cytokeratin
Cytokeratin 5 (CK5)
Cytokeratin 7 (CK7)
Cytokeratin 20 (CK20)
Cytologic atypia
Cytomegalovirus (CMV)
Cyst
Cystic degeneration
Cytoplasm

D

Degenerative changes
Desmin
Desmoplasia
DIF
Differentiated
Diffuse
Direct immunofluorescence
Distal
Duct
Dyskeratotic cells
Dysplasia

E

E-cadherin
Edema
Edematous
Endophytic
Endosalpingiosis
Eosinophil
Eosinophilic abscess
Epithelial cells
Epithelioid cells
Epithelium
Epstein-Barr virus (EBV)
Epstein-Barr virus-encoded small RNAs (EBER)
Estrogen receptor (ER)
Erosion
Excision
Exophytic
Extranodal extension (ENE)
Extraparenchymal extension

F

Fat necrosis
Fibroblasts
Fibrosis
Fibrinoid necrosis
Fibrinopurulent exudate
Fibrovascular core
Fine needle aspiration biopsy (FNAB)
Flow cytometry
Fluorescence in situ hybridization (FISH)
Foamy histiocyte
Focal
Foveolar metaplasia
Frozen section
Fuhrman grade​

G

GATA-3
Gastric heterotopia
Gland
Glandular cells
Grade
Granulation tissue
Granuloma
Grocott (GMS)
Gross
Gross description

H

Hamartoma
HBME-1
Helicobacter pylori
H. pylori
Hematoxylin and eosin (H&E)
Hematopoietic cells
Hepatocytes
Heterogeneous
Her2
Herpes simplex virus (HSV)
High grade
High grade dysplasia
High grade squamous intraepithelial lesion (HSIL)
Histiocytes
HMB-45
Homogeneous
Human papillomavirus (HPV)
Hurthle cell
Hyams grade
Hypercellular
Hyperchromatic
Hyperchromasia
Hypergranulosis
Hyperkeratosis
Hyperplasia
Hypertrophy
Hypocellular

I

Immunohistochemistry (IHC)
Immunoglobulin
Immunoreactivity
Immunostain
Inadequate
Infiltrative
Infiltration
Inflammation
Inflammatory cell
Ischemic necrosis
Isolated tumour cells (ITCs)
In situ hybridization (ISH)
Insufficient for diagnosis
Intercellular bridges
Intestinal metaplasia
Intracytoplasmic
In-transit metastasis
In toto
Invasion

J

K

Karyotype
Keratinization
Keratinocytes
Ki-67
Ki-67 labeling index
Koilocytes
KRAS

L

Lamina propria
Larynx
Lesion
Leukemia
Leukocyte
Limited for interpretation
Low grade
Low grade dysplasia
Low grade squamous intraepithelial lesion (LSIL)
Lymphatic invasion
Lymphoid aggregate
Lymphocyte
Lymphocytosis
Lymphoid cells
Lymphovascular invasion (LVI)
Lymphoma
Lymph node

M

Macrophages
Margin
Mass
Mast cells
Malignant
Malignant neoplasm
Malignant spindle cell neoplasm
Malignant transformation
Melanocyte
Melanoma
Melan-A
Metaplasia
Metastasis
Metastatic carcinoma
Metastatic adenocarcinoma
Mesothelial cells
MIB-1
Microcalcification
Minimally invasive
Minimal residual disease (MRD)
Mismatch repair (MMR)
Mitosis
Mitotic figure
Mucosa
Mucin
Mucinous
Mucicarmine
Multifocal
Myoepithelial cells
Myxoid

N

Natural killer cells (NK cells)
Neoplasm
Necrosis
Necrotizing granulomatous inflammation
Negative for malignancy
Neutrophil
Neuroendocrine cell
Neuroendocrine differentiation
Neuroendocrine tumour (NET)
Neuroendocrine carcinoma (NEC)
Non-diagnostic
Non-Hodgkin lymphoma
Non-invasive
Nonkeratinizing
Nonkeratinizing squamous cell carcinoma (NKSCC)
Non-necrotizing granulomatous inflammation
Non-reactive
Non-small cell carcinoma
Nottingham histologic grade
NRAS
Nuclear atypia
Nucleus
Nucleoli

O

Oncocytic
Oral cavity
Oropharynx
Osteoid
Oxyntic mucosa​

P

p16
p40
p53
p63
Pancreatic heterotopia
Pancreatic metaplasia
Paneth cell metaplasia
Papillary
Papilloma
Parenchyma
PASS score
PAX5
PAX8
Periodic Acid Schiff (PAS)
Periodic Acid Schiff plus Diastase (PAS-D)
Peripheral nerve sheath tumour
Parakeratosis
PD-L1
Perineural invasion (PNI)
Plasma cells
Plasmacytoid cells
Pleomorphic
Polyp
Precursor
Progesterone receptor (PR)
Proximal
Prognosis
Poorly differentiated
Poorly differentiated neuroendocrine carcinoma
Positive for malignancy
Psammoma bodies
pTNM

Q

R

Red blood cells (RBCs)
Reactive changes
Resection
Rhabdoid
Ring sideroblasts​

S

S100
Sarcoma
Sarcomatoid
Schistocytes
Sebaceous glands
Sentinel lymph node
Signet ring cell
Sinonasal tract
Small bowel mucosa
Smooth muscle actin (SMA)
Solar elastosis
SOX10
Stoma
Stroma
Squamous cell
Squamous epithelium
Squamous metaplasia
Squamous mucosa
Special stain
Specimen
Spindle cell
Spindle cell neoplasm
Spongiosis
Spongiotic
Spread through air spaces (STAS)
Synaptophysin
Syndrome​

T

T cells
Tangentially sectioned
Transformation zone
TTF-1
Tubal metaplasia
Tumour
Tumour bed
Tumour capsule​
Tumour deposit
Tumour infiltrating lymphocytes (TILs)
Tumour necrosis
Tumour regression
Thyroglobulin

U

Ulcer
Undifferentiated
Urothelial cell​

V

Vascular lesion
Vasculitis
Vascular invasion
Viral cytopathic effects
Virus

W

Well differentiated
A+ A A-