Histopathology Glossary of Abbreviations

A

AA
Anaplastic Anemia. Anaplastic Anemia is an uncommon disease resulting in deficiencies of blood cell production by bone marrow.
ABC
Advanced Breast Cancer. Metastatic or Stage IV breast cancer.
AD
Alzheimer’s Disease. This is a dementia that leads to deterioration of important mental functions such as thinking.
Adenocarcinoma
A malignant tumor that arises in mucus-secreting glands.
Adjunct Agent
A drug or substance used alongside a primary therapy during cancer therapy.
Adjuvant Chemotherapy
While chemotherapy is generally a standalone treatment or used in conjunction with radiation following surgical resection, adjuvant chemotherapy describes the use of chemotherapy in comparison to other cancer treatments.
Adjuvant Radiation Therapy
Radiation therapy used after primary treatment for the prevention of a cancer relapse.
AIDS
Acquired Immune Deficiency Syndrome. The final stage of HIV where the T-cell (CD4 cell) count falls below 200.
ALAT / ALT
Alanine aminotransferase / alanine transaminase. ALAT is a catalyst of two parts of the alanine cycle, found in plasma and body tissues, most commonly found in the liver.
ALCL
Anaplastic Large-cell Lymphoma. This is a rare form of non-Hopkins lymphoma (NHL), but is more commonly seen as a T-cell lymphoma.
ALK
Anaplastic Lymphoma Kinase. ALK is one of the receptor tyrosine kinase (RTK) family of enzymes, which have significant roles in the proliferation and differentiation of cells. Recent studies have suggested that ALK may be a key target for drug development in oncological medicine.
ALL
Acute Lymphocytic Leukemia. A fast-growing cancer of the antibody-producing lymphocytes. This disease is characterized by a greater presence of immature lymphocytes (lymphoblasts) than normally needed in the blood and bone marrow, and is the most common of pediatric cancers.
AMKL
Acute Megakaryocytic Leukemia. This is a rare type of leukemia where most of the blasts are megakaryoblastic.
AML
Acute Myeloid Leukemia. A form of cancer characterized by the presence of too many immature granulocytes in the bone marrow and blood.
Anaplastic
Cancer cells that proliferate quickly and unlike normal cells.
ANLL
Acute Non-Lymphocytic Leukemia. Too many immature white blood cells are present in the blood and bone marrow. ANLL is also known as Acute Myeloid Leukemia.
Antigen
A foreign substance that results in the body triggering an immune response.
Archived Tumor Sample
Tumor sample preserved and stored through common processes.
ARMS
Alveolar Rhabdomyosarcoma. This is a cancer that usually affects the skeletal cells in the trunk, arms, and legs.
Aromatase Inhibitor
Medication that inhibits the aromatase enzyme, resulting in decreased levels of estrogen in the body.

B

B-ALL
B-Cell Acute Lymphoblastic Leukemia. A type of clonal malignancy characterized by excess accumulation of lymphoblasts that phenotypically resemble the early stages of normal B-cell differentiation.
BCC
Basal Cell Carcinoma. BCC is a type of skin cancer that creates lesions and uncontrolled growth in the basal cells of the epidermis.
Biomarker
A biomarker may indicate the presence of a substance that can identify a particular disease or state of infection, as well as give information about the characteristics of a disease.
BRCA1 and BRCA2
These genes typically assist in regulating cell growth, and mutations of these genes are the most well-known genes linked to breast and ovarian cancer development.
Bx
Biopsy. A tissue sample taken for closer examination or testing, for diagnostic purposes.  Samples gathered for this purpose are subject to legally mandated retention protocols, and under certain conditions may be released as specimens for scientific research.

C

Ca
Cancer; carcinoma. Cancer is a disease in which some cells begin to replicate uncontrollably and spread into surrounding tissues.
Cancer Staging
Assigning a scale number to describe the spreading of a cancer. See Pathologic (or Histologic) Grade for more information.
Carcinoma in situ
A cluster of abnormal cells which have not spread from the tissue of origin nor invaded the basement membrane.
CCF
Congestive Cardiac Failure. This is a chronic condition in which the heart is functioning at sub-normal efficiency.
CD
Cluster of Differentiation. This is a protocol used for the identification and investigation of cell surface molecules providing targets for the immunophenotyping of cells.
CEA
Carcinoembryonic Antigen. These are glycoproteins, produced during fetal development, involved in cell adhesion.
CGL
Chronic Granulocytic Leukemia. A slow-progressing disease of the blood and bone marrow in which too many granulocytes are produced. This is also known as Chronic Myeloid Leukemia.
Chemotherapy
Treating cancer cells through the use of cytotoxic drugs. This treatment may be used alongside surgery, or with alternative treatment options.
Chromosome
A structure found in the nucleus of a cell which carries genetic information.
CLL
Chronic Lymphocytic Leukemia. This is a type of leukemia that affects cells designated to be white blood cells in the bone marrow, which then move into the blood steam.
CLIA
Clinical Laboratory Improvement Amendments. These federal regulatory standards govern clinical laboratory testing conducted on humans in the United States were established in 1988.
Clinical Trial
A research study involving human subjects to test the effectiveness and safety of technologies, drugs, and procedures.
Clinically Validated
Ensuring that a procedure, data, or test is correct.
CML
Chronic Myeloid Leukemia. Immature myeloid cells form the abnormal BCR-ABL gene. Also known as chronic myelogenous leukemia.
CMML
Chronic Myelomonocytic Leukemia. This cancer affects the bone marrow’s blood-forming cells, and spreads into the blood stream.
CMS
Center for Medicare and Medicaid Services.
CMV
Cytomegalovirus. This is a common virus that, once affected, lasts a lifetime. It is a genus in the order Herpesvirales.
COD
Cause of Death.
Colectomy
Surgical removal of damaged colon tissue.
Colitis
An inflamed colon, which may be present in many forms.
Colon Polyp
A fleshy clump of cells that grow on the inside lining of the colon.
Colonoscopy
An exam conducted to view the conditions of the inside of the colon through the use of a small fiber-optic scope.
Common Rule
45-CFR-46. The Common Rule is a set of federal regulations governing patient protection for research conducted with federal funds, or at sites supported with federal funds.
Core Biopsy
The procedure which obtains a cylindrical tissue sample through the use of a hollow needle, usually used to test for breast cancer.
CRC
Colorectal Carninoma. This is a common cancer that affects the large intestine and/or rectum.
CRO
Contract Research Organization. An organization that performs research services on a contractual basis.
CSF
Cerebrospinal Fluid. This is a clear, cushioning fluid produced by the choroid plexuses. It is found in the brain and spinal cord.
CSLI
Clinical and Laboratory Standards Institute. CSLI is a non-profit organization aimed at developing clinical and laboratory standards.
CTC
Circulating Tumor Cell. These are cells from a primary tumor that circulate through the body via the bloodstream.
CTCL
Cutaneous T-cell Lymphoma. CTCL is a non-Hodgkin lymphoma that causes accelerated growth of T-cells.

D

DI
Diabetes Insipidus. DI is a rare type of diabetes characterized by a deficiency in vasopressin, a hormone produced by the pituitary gland.
Diagnosis
Using examinations, test results, and symptoms to identify a condition.
DIG Staining
Digoxigenin, a hapten which can be bound to nucleotides and sugars, is used as an immunohistochemical marker for in situ hybridization.
Distant Recurrence
A cancer affecting parts of the body away from its tissue of origin.
DLBCL
Diffuse Large B-cell Lymphoma is the most common type of non-Hodgkin lymphoma. It affects lymphocytes, has several subtypes, and is very aggressive.
Dukes Staging System
A system consisting of four stages used to assign levels of severity to rectal cancers.
Dysplasia
Cells which undergo abnormal changes and may potentially develop into cancer.

E

Early-Stage Invasive Breast Cancer
Stage I, stage II, and in some instances, stage III breast cancer.
EBV
Epstein-Barr Virus. This is human herpesvirus 4, and can lead to infectious monocucleosis.
EGFR
Epidermal Growth Factor Receptor. Regulation of EGFR can be involved with some cancers. Related biomarkers can be used to predict the responsiveness of some cancers to certain treatments.
EMC
Extraskeletal Myxoid Chondrosarcoma. This is a very rare soft tissue sarcoma. While it does not progress quickly, this neoplasm has a tendency to recur and metastasize locally. 
Endoscope
A medical instrument used to examine the internal parts of a body.
Endoscopy
Examination of an interior body part through the use of an endoscope.
ER
Estrogen Receptor. A protein found on some cells that receives hormone signals.

F

FFPE
Formalin Fixed Paraffin Embedded tissues. Sections from a FFPE block, composed of dehydrated tissue fixed with neutral buffered formalin and then infused and embedded in paraffin, are sliced for use. 
FISH
Fluorescence In Situ Hybridization. This is a coming staining/screening technique in which fluorescent probes are used to indicate target sequences on chromosomes.
FNA
Fine Needle Aspiration. A biopsy performed with percutaneous insertion of a very thin needle to draw a fluid sample. Also, may refer to Fine Needle Aspirate, which is the fluid that is gathered by such a procedure. 
Functional Genomics
The global-scale study of gene and protein expression and function through the use of genomic data.

G

Gastroenterologist
A doctor specializing in gastrointestinal tract diseases.
Gastroenterology
The medical branch which studies the stomach and intestines.
Gene
Heredity units passed from parent to offspring.
Gene Expression
The process of using information from a gene to create a genetic product.
Gene Expression Profile
The activity levels of numerous genes from a specimen.
Genetics
The study of heredity, genes, and characteristic variations.
Genome
The complete set of DNA for an organism.
Genomic Test
A test that examines the changes in gene activity, often used to predict how a cancer may progress or be treated.
Genomics
The study of genomes.
GIST
Gastrointestinal Stromal Tumors. A form of soft tissue sarcoma, the most common mesenchymal tumors found in or near the gastrointestical tract.
Gleason Score
This is a prostate cancer prognosis tool that indicates the likelihood of a tumor spreading on a scale of 2 to 10. 2 is less likely to spread, and 10 is very likely to spread.

H

Hand Foot Syndrome
Also known as Palmar-Plantar Erythrodysesthesia. Hand Foot Syndrome is characterized by redness, swelling, and pain on the palms and/or soles of the hands and feet. It can be a side effect resulting from several types of cancer treatments.
Hb
Hemoglobin (US spelling); Haemoglobin (alternate spelling). The protein in red blood cells responsible for transporting oxygen. Abnormally elevated or reduced hemoglobin counts, are associated with a number of pathologies.  Several inherited single gene disorders are known to affect the structure and thus function of hemoglobin molecules.  
HCC
Hepatocellular carcinoma. This is the most prevalent form of liver cancer. HCC is a primary cancer (originating in the liver) commonly caused by Cirrhosis. 
HCL
Hairy Cell Leukemia. HCL is a B-cell leukemia in which thin, hair-like tendrils develop around the B-lymphocytes.
HD
Hodgkin’s Disease. HD is a type of lymphoma. Due to the expansive lymphatic system, Hodgkin’s Disease may originate nearly anywhere in the body, but most commonly originates in the lymph nodes of the upper body, particularly the neck.  
HER2
Human Epidermal Growth Factor Receptor 2. This is a protein that promotes the growth of cancer cells. It is caused by a gene mutation, which can occur in many types of cancer. This gene mutation only occurs in cancer cells and can not be inherited.
H&E Staining
Hematoxylin and Eosin stain. H&E Staining utilizes hematoxylin (a basic, dark blue/violet stain) and eosin (an acidic, red/pink stain), and is the most commonly used stain for diagnosing medical issues.
HIPAA
Health Insurance Portability and Accountability Act. Established in the early 1990’s, HIPAA is a federal regulation that standardizes electronic data exchanged within health care transactions, speficies security requirements for stored or exchanged health information.
HIV
Human Immunodeficiency Virus. HIV is a virus, contracted through contact with infected blood, semen, or vaginal secretions, that destroys CD4 cells, resulting in a compromised immune system. This is a lifelong virus that progresses into AIDS. While there is currently no cure, medication is available to slow the progression.
HNPCC
Hereditary Nonpolyposis Colon Cancer. Also known as Lynch Syndrome. This is an inherited syndrome that increases the risk of developing several types of cancer, especially colorectal cancers.
HNSCC
Head and Neck Squamous Cell Carcinoma. Cancer occuring in the upper aerodigestive tract, in the mucous membranes of the throat, mouth, and nose. Once it metastasizes, the prognosis worsens. 
Hormonal Treatment
Hormone Therapy. These medications are used to reduce and regulate the hormones in the body. Hormone therapy is a common treatment for hormone-receptor-positive breast cancer.Hormonal therapies include aromatase inhibitors, selective estrogen receptor modulators, or estrogen receptor down regulators.
Hormone Receptor
A protein on the surface of or within cells which bind to specific hormones. On tumorous cells, the hormones that attach to these receptors often signal cell growth.
HPV
Human Papillomavirus. A very common sexually transmitted infection that often causes warts, but may lead to some types of cancer, particularly cervical cancer. There are over 150 types of HPV, each identified with a specific number. 
HTLV
Human T-cell Leukemia-Lymphoma Virus. This is a retrovirus that targets T-cells and may lead to T-cell cancers or a demyelinating disease. HTLV is very similar to HIV.

I

IEC
International Electrotechnical Commission. Defines common standards that are often used as guidelines by organizations working in the histology, pathology and biorepository industries.
IHC
Immunohistochemistry. This method uses antigen-antibody interactions to localize particular antigens in FFPE tissues.
Invasive Cancer
Cancer that has spread away from its tissue of origin.
IQCP
Individualized Quality Control Plan. This is a quality control policy enforced by CLIA.
IRB
Institutional Review Board. This is a committee that approves and oversees research involving human participants to assure compliance with all relevant ethics and regulations.
ISH
In Situ Hybridization. This is a common staining/screening technique in which probes are used to show the physical location of target molecules on within sectioned tissue.
ISO
International Organization for Standardization. Defines common quality standards to be utilized as guidelines in industrial commerce and research.

K

KRAS
Kirsten rat sarcoma viral oncogene homolog. This is one of three known human RAS genes, which together are the most common oncogenes in human cancer.  KRAS mutations are found in approximately 90% of pancreatic carcinomas, and in very high rates with leukemias, lung cancers, and colorectal cancers, as well.

L

LC Codes
Laboratory Certification Codes. Established by CLIA to provide specialty and subspecialty information about the credentials of a lab.
LCH
Langerhan’s Cell Histiocytosis. This is a rare disease characterized by excess proliferation of Langerhan’s cells forming granulomas, frequently in the dermis or bones. Commonly diagnosed between ages 1 and 3.    
LMM
Lentigo Maligna Melanoma. This is a type of melanoman commonly found in skin that has suffered chronic sun damage.
Local Recurrence
When a cancer reappears in or near its place of origin.
Lumpectomy
Surgically removing a lump from the breast.

M

Malignant
In terms of tumors, malignant tumors are aggressive and are able to invade nearby tissue and metastasize to other regions of the body.
Mastectomy
A surgical operation that removes all or a section of the breast tissue.
MDS
Myelodysplastic Syndromes. MDS refers to a group of disorders in which disordered haematopoiesis results in insufficient quantities of viable blood cells.
MEN
Multiple Endocrine Neoplasia. A group of rare inherited disorders that affect the endocrine system’s glands.
Metastasis
The spread of cancer to other organs of the body, or the spread of the tumor from its primary site. Typically in cancers, the cancer will move to a lymph node first, then to more distant areas of the body.
Mets
Metastatic cells at a secondary location.
MI
Myocardial Infarction, commonly referred to as a heart attack.
MM
Malignant Melanoma. This is the most serious type of skin cancer.
MPNST
Malignant Peripheral Nerve Sheath Tumor. A sarcoma that affects the connective tissues surrounding nerves.
Molecular Diagnostics
The analysis of biomarkers in the genome and proteome.
MRT
Malignant Rhabdoid Tumor. A highly aggressive kidney tumor usually found in children.

N

NAT
Normal Adjacent Tissue. This is healthy tissue with no indications of a disorder found alongside damaged or diseased tissue, typically fromresected material and cadaveric specimens.  Because normal, healthy tissue is not typically removed from healthy patients, researchers needing normal controls for their studies may consider whether NAT will meet the study criteria.  
NBCCS
Nevoid Basal Cell Carcinoma Syndrome. Multiple basal cell skin cancers and jaw cysts characterize this hereditary condition. It is also known as Gorlin syndrome.
NED
No Evidence of Disease.
NHL
Non-Hodgkin’s Lymphoma. This is a common cancer that originates in the lymphatic system, particularly the lymphocytes, a white blood cell.
NM
Nodular Melanoma. This is the most aggressive melanoma, characterized by its growth in depth rather than diameter. It often appears where no previous lesion existed.
NMSC
Non Melanoma Skin Cancer. This includes all skin cancers that are not melanomas. The most common types are basal cell carcinoma and squamous cell carcinoma.
NPC
Nasopharyngeal Cancer. Cancer that affects the cells in the upper region of the pharynx.
Node-Negative Breast Cancer
Breast cancer that has not yet spread to the lymph nodes.
Node-Positive Breast Cancer
Breast cancer that has invaded the lymph nodes (usually the axillary nodes).
NSCLC
Non-Small Cell Lung Cancer. This is the most common category of lung cancer.

O

OCT
Optimum Cutting Temperature. A medium used to mount tissue for sectioning in a cryostat.
Oncology
The analysis and treatment of cancer and tumors.
OS
Osteogenic Sarcoma. This is a bone cancer usually formed in the new bone tissue created during growth.

P

Pathology
1) Study of the essential nature of diseases and especially of the structural and functional changes produced by them.
2) Anatomic and physiological deviations from the normal that constitute disease or characterize a particular disease.
3) Treatise on or compilation of abnormalities.
Pathologic (or Histologic) Grade
(of cancer cells) The scoring of tumor cells to show how far they have evolved from a normal cell pattern. The lower the number, the closer the cells are to normal. Normal cells tend to grow and multiply slowly to form well-organized tissues made up of differentiated cells. Cancer cells are more “generic” (i.e., less differentiated into the specific cell type usually found in that tissue).
G1: Well differentiated – low grade, tends to grow slowly
G2: Moderately differentiated – Intermediate grade
G3: Poorly differentiated – High grade
G4: Undifferentiated – High grade, tends to be highly invasive.
PEG
Polyethylene glycol. This electrolyte-based solution is generally used to prepare the bowel before a gastrointestinal exam.
PLB
Primary Lymphoma of Bone. This is a rare form of bone cancer.
PNS
Peripheral Nervous System. The system of nerves outside of the brain and spinal cord.
Polyp
A fleshy, usually benign, tumor that grows from an organ’s mucous lining.
PR
Progesterone Receptor. A protein, found on cells, that progesterone molecules can attach to.
PSA
Prostate-Specific Antigen. A glycoprotein enzyme in the KLK3 gene. Elevated levels of this protein, produced exclusively by the prostate, may be observed in the blood of men who have prostate diseases, including cancer.

R

Radiation Therapy
A form of cancer therapy that uses radiation to destroy cells at the site of the tumor.
RCC
Renal Cell Carcinoma. Cancer of the kidneys.
Recurrence
The reappearance of cancer post treatment.
Resection
A surgical operation that removes cancerous tissue as well as normal adjacent tissue.
RMS
Rhabdomyosarcoma. This is a rare cancer that affects skeletal muscle cells.

S

Sarcoma
A malignant tumor that arises from nonepithelial and connective tissue.
SCC
Squamous Cell Carcinoma. Cancer that affects squamous cells in the body. SCC has many subtypes.
SCLC
Small Cell Lung Cancer. This aggressive cancer is also known as oat cell cancer.
Synchronous Cancer
Two or more primary cancers present at the same time.
Syndrome
A group of symptoms and signs which identify a particular condition.

T

Tamoxifen
An estrogen-receptor-positive breast cancer medication that acts as an estrogen inhibitor.
TCC
Transitional Cell Carcinoma. A cancer affecting the urinary system, usually in the bladder.
TCP
Thrombocytopenia. TCP is a condition in which one has a deficiency of blood platelets.
TNM
TNM Classification of Malignant Tumors. This is a system that uses descriptions of Tumors, Nodes, and Metastasis (TNM) to classify the extent of a cancer.
Tumor
A benign or malignant mass of abnormal tissue.
Tumor Grade
A description of a tumor based on a comparison of the abnormal cells to normal cells of the same type.

U

Ulcerative colitis
An inflammatory bowel disease that causes the formation of ulcers in the top layers of the large intestines’ inner lining.

W

WBC
White Blood Cell count. The number of white blood cells found in the body.
Wire Localization Biopsy
A breast cancer diagnoses method that is conducted when a mammogram displays abnormalities which cannot be felt.
WM
Waldenstrom’s Macroglobulinemia. This is a rare non-Hodgkin’s lymphoma in which the excess B-lymphocytes produce an antibody, immunoglobulins.

Y

YST
Yolk Sac Tumor. Also known as a germ cell tumor, this rare cancer affects the cells lining the embryo’s yolk sac, and is then usually seen in the ovaries, testes, or sacrococcygeal area.