TNM Classification

The letters T-N-M are abbreviations and stand for:

T = tumour, in the sense of primary tumour;

N = Nodus lymphaticus (lymph node), in the sense of regional lymph node metastases;

M = metastasis, in the sense of haematogenic distant metastases; T = primary tumor

Tis or Cis: tumour in situ, carcinoma in situ; T1, T2, T3, T4: indicates the size of the primary tumour (T1=small, T4=large)

N = Regional lymph node metastases N0: no indication for lymph node metastases N1, N2, N3, N4: indicates the extent of regional lymph node metastasis

M = distant metastases M0: no indication for distant metastases M1: distant metastases detected

If the primary TNM formula must be changed due to later findings (surgical treatment, histological examination), this is indicated by special additives. A prefixed ″p″ means, for example, that the stadium division was carried out taking into account a pathohistological OP finding (pTNM former).

Other tumor characteristics:

Typing (cell type): histological classification of a tumor according to its original tissue. Example: adenocarcinoma. Squamous cell carcinoma, leiomyosarcoma; important for further treatment because the individual cell types respond very differently to radiation treatment or chemotherapy.

Grading (cell differentiation): The term means the degree of histological malignancy.

G1 means high differentiation (good prognosis, because highly differentiated tumors with a low degree of malignancy (in practice: bronchial carcinoids, rarely also squamous epithelial or azinic (berry-shaped) adenocarcinomas))

G2 mean differentiation, mean highly differentiated tumors with mean malignancy (in practice: mostly bronchial wall gland carcinomas, rarely also squamous epithelial or papillary adenocarcinomas)

G3 extensive de-differentiation (poor prognosis, because little differentiated tumors with high degree of malignancy (in practice: depending on staging) all advanced non-small cell lung carcinomas).

G4 'undifferentiated tumors with a very high degree of malignancy (in practice: depending on staging, all small cell lung carcinomas).

R-Classification: For the prognosis after an operation, it is decisive whether tumour remains remain in the body.

R0 resection: no residual tumor

R1-Resection: microscopic tumor residue

R2 resection: macroscopic tumor residue, infiltration depth histologically detectable depth extension. The question is now whether the primary tumor has already metastasized to the lymphatic or bloodstream (probably) in proven vascular invasions.