TNM classification


TNM classification

Oncology An international system for staging malignancy which measures 3 major parameters of a cancer: T–size or extent of the primary tumor, as determined by clinical exam, endoscopy, laparoscopy, biopsy or resective procedures, categorized as being 1-4 and a-d depending upon site, size, and spread; N–number of involved lymph nodes, categorized as X–unknown status, 0–none identified, 1–one to several, 2–a whole bunch of positive LNs; M-X, unknown presence or absence of metastases. See Staging. TNM classification for staging malignancy T Tumor Tis Carcinoma in situ Ta Non-invasive Tx Cannot be evaluated for nonspecified reasons T0 Localized tumor T1 Lesion extends to muscle–bladder, colon, breast T1a < 0.5 cm in greatest dimension T1b < 1.0 cm in greatest dimension T1c < 2.0 cm in greatest dimension T2 Invasion into muscle T3 Persistent induration of organ after resection  T3a Invasion to deep muscle  T3b Invasion through the organ T4 Tumor invasion or fixation  T4a Adjacent organ invasion  T4b Fixation to bladder or colonic wall; in breast, edema N Nodes N0 No lymph node metastasis N1 One regional lymph node metastasis N2 Multiple, mobile regional lymph node metastases N3 Fixed regional lymph node metastases N4 Beyond regional lymph node involvement NX Lymph nodes, not evaluable M Metastasis M0 No evidence of metastases M1 Distant metastases are present MX Distant metastases not evaluable

TNM classification

A method of classifying malignant tumors with respect to primary tumor, involvement of regional lymph nodes, and presence or absence of metastases. See also: classification