TNM classification

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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