| Abbreviations | Meaning |
 | IDS-CRC | International Documentation System-Colorectal Cancer |
 | IEC | Intraepithelial Carcinoma |
 | IECA | Intraepithelial Carcinoma |
 | IESS | Intergroup Ewing's Sarcoma Study (USA) |
 | IESS | Intergroup Ewing Sarcoma Study |
 | IFCR | International Foundation For Cancer Research |
 | II | Carcinoma Of The Subvaginal Tissue Without Involving The Pelvic Wall [International Federation Of Gynecologists And Obstetricians (FIGO) Classification] |
 | II | Endometrial Carcinoma Involving The Corpus And Cervix But No Other Tissues [International Federation Of Gynecologists And Obstetricians (FIGO) Classification] |
 | III | Endometrial Carcinoma Extending Outside The Uterus But Not Outside The True Pelvis [International Federation Of Gynecologists And Obstetricians (FIGO) Classification] |
 | III | Vaginal Carcinoma Extending To Pelvic Wall [International Federation Of Gynecologists And Obstetricians (FIGO) Classification] |
 | ILL | Intermediate Lymphocytic Lymphoma |
 | ILL | Interlibrary Loan; Intermediate Lymphocytic Lymphoma |
 | ILSG | International Lymphoma Study Group |
 | INSS | International Neuroblastoma Staging System |
 | IPA | Infiltrating Pancreatic Ductal Adenocarcinoma |
 | IPMT | Intraductal Papillary Mucinous Tumor |
 | IRS | Intergroup Rhabdomyosarcoma Study |
 | IT | Intratumoral |
 | ITP | Islet-cell Tumor Of The Pancreas |
 | ITT | Interstitial Tumor Therapy |
 | IV | Endometrial Carcinoma Extending Outside The True Pelvis Or Involving The Bladder And Rectum [International Federation Of Gynecologists And Obstetricians (FIGO) Classification] |
 | IVA | Endometrial Carcinoma Spreading To Adjacent Organs [International Federation Of Gynecologists And Obstetricians (FIGO) Classification]; Vaginal Carcinoma With Metastases To Adjacent Organs [International Federations Of Gynecologists And Obstetricians (FIGO) Classification] |
 | IVB | Endometrial Carcinoma Spreading To Distant Organs [International Federation Of Gynecologists And Obstetricians (FIGO) Classification]; Vaginal Carcinoma With Metastases To Distant Organs [International Federation Of Gynecologists And Obstetricians (FIGO) Classification] |
 | IVBAT | Intravascular Bronchioalveolar Tumor |
 | IVL | Intravascular Lymphomatosis; Involucrin |
 | JCML | Juvenile Chronic Myelogenous Leukemia |
 | JCN | Jefferson Cancer Network |
 | JGCT | Juvenile Granulosa Cell Tumor; Juxtaglomerular Cell Tumor |
 | JOS | Jaw Osteosarcoma |
 | K-MSV | Kirsten Murine Sarcoma Virus |
 | KB | Human Oral Epidermoid Carcinoma Cells |
 | KCC | Cathodal Closing Contraction; Kulchitzky Cell Carcinoma |
 | KIMSA | Kirsten Murine Sarcoma |
 | KIMSV, KIMSV | Kirsten Murine Sarcoma Virus |
 | KIN | Keratinocytic Intraepidermal Neoplasia |
 | KNRK | Kirsten Sarcoma Virus In Normal Rat Kidney |
 | KS | Kaposi Sarcoma |
 | KS/OI | Kaposi Sarcoma With Opportunistic Infection |
 | KSHV | Kaposi Sarcoma-associated Herpesvirus |
 | L0 | No Evidence Of Lymph Node Metastases [TNM (tumor Node-metastasis) Classification] |
 | L1 | Acute Lymphoblastic Leukemia With Lymphoblasts, Scanty Cytoplasm And Inconspicuous Nucleoli [FAB (Franco-American-British) Classification]; Lymph Node Metastases Assessed [TNM (tumor-node-metastasis) Classification] |
 | L2 | Acute Lymphoblastic Leukemia With Large Pleomorphic Blasts, Abundant Cytoplasm, And Prominent Nucleoli [FAB (Franco-American-British) Classification] |
 | L3 | Acute Lymphoblastic Leukemia Having Blast With Basophilic Vacuolated Cytoplasm [FAB (Franco-American-British) Classification] |
 | LA | Leukemia Antigen |
 | LAA | Left Atrial Appendage; Left Atrial Area; Left Auricular Appendage; Leukemia-associated Antigen; Leukocyte Ascorbic Acid |
 | LABC | Locally Advancing Breast Cancer |
 | LAC | Lung Adenocarcinoma Cells |
 | LALL | Lymphomatous Acute Lymphoblastic Leukemia |
 | LAP | Leukemia-associated Phenotype |
 | LAP | Leukemia-associated Phosphoprotein |