CS Extension

Notes

**Note 1**: The intrinsic muscles of tongue are four paired muscles within the tongue which control its shape. The extrinsic muscles originate from structures outside the tongue and control its positioning. **Note 2**: The assignment of T1 and T2 categories for tumors of the oropharynx is based on tumor size. A physician's statement of the T category may be used to code CS Tumor Size and/or CS Extension if this is the only information in the medical record regarding one or both of these fields. However the two fields are coded independently: for example the record may document size but not extension, other than the physician's statement of the T category. Use codes 405, 410, 650, 775, 810, or 815 as appropriate to code CS Extension based on a statement of T when no other extension information is available. **Note 3**: Use code 300 for localized tumor only if no information is available to assign codes 100, 200, 400, 405, or 410.
Code Description AJCC 7 T AJCC 6 T Summary Stage 1977 T Summary Stage 2000 T
000 In situ, intraepithelial, noninvasive Tis Tis IS IS
100 Invasive tumor on one side confined to posterior one-third of tongue:
Lamina propria
Submucosa
Extension Size AJCC7 Extension Size AJCC6 L L
200 Musculature, intrinsic or NOS Extension Size AJCC7 Extension Size AJCC6 L L
300 Localized, NOS
Midline tumor
Extension Size AJCC7 Extension Size AJCC6 L L
400 Base of tongue tumor crosses midline
Tumor of lingual tonsil on both sides
Extension Size AJCC7 Extension Size AJCC6 L L
405 Stated as T1 with no other information on extension Extension Size AJCC7 Extension Size AJCC6 L L
410 Stated as T2 with no other information on extension Extension Size AJCC7 Extension Size AJCC6 L L
500 Anterior two-thirds of tongue for base of tongue
Lingual tonsil for base of tongue
Base of tongue for lingual tonsil
Floor of mouth
Lower gingiva
Extension Size AJCC7 Extension Size AJCC6 RE RE
530 Sublingual gland Extension Size AJCC7 Extension Size AJCC6 RE RE
600 OBSOLETE DATA RETAINED V0200
Epiglottis, lingual surface assigned to T3 in AJCC 7, see code 640

Epiglottis, lingual (pharyngeal) surface
Glossoepiglottic fold
Glossopharyngeal fold
Lateral pharyngeal wall
Pharyngoepiglottic fold
Tonsillar pillars and fossae
Tonsils
Vallecula
ERROR: Extension Size AJCC6 RE RE
610 Glossoepiglottic fold
Glossopharyngeal fold
Lateral pharyngeal wall
Pharyngoepiglottic fold
Tonsillar pillars and fossae
Tonsils
Vallecula
Extension Size AJCC7 Extension Size AJCC6 RE RE
620 Soft palate, inferior surface or NOS including uvula Extension Size AJCC7 Extension Size AJCC6 D RE
640 Epiglottis, lingual surface T3 Extension Size AJCC6 RE RE
645 640 + 620

Epiglottis, lingual surface plus soft palate
T3 Extension Size AJCC6 D RE
650 Stated as T3 with no other information on extension T3 Extension Size AJCC6 RE RE
710 Mandible for lingual tonsil T4a T4a RE D
715 710 + 620

Mandible plus soft palate
T4a T4a D D
720 Mandible for base of tongue T4a T4a D D
740 Medial pterygoid muscle
Hard palate
T4a T4a D D
750 Musculature of tongue, extrinsic:
Genioglossus
Geniohyoid
Hyoglossus
Mylohyoid
Palatoglossus
Styloglossus
T4a T4a D D
760 Hypopharynx T4a T4a D D
770 Larynx T4a T4a D D
775 Stated as T4a with no other information on extension T4a T4a RE RE
780 Skin T4b T4b D D
790 Lateral nasopharynx
Lateral pterygoid muscle
Pterygoid plates
T4b T4b D D
795 (770, 780, or 790) + 760 T4b T4b D D
800 OBSOLETE DATA REVIEWED AND CHANGED V0203
Recode involved structures to 620, 645, 715, 760, 790, or 795 as appropriate.

Contiguous extension to:
Base of skull
Carotid artery
Hypopharynx
Lateral nasopharynx
Lateral pterygoid muscle
Pterygoid plates
Uvula
ERROR: ERROR: ERROR: ERROR:
805 Further contiguous extension including:
Skull base
Carotid artery (encased)
T4b T4b D D
810 Stated as T4b with no other information on extension T4b T4b D D
815 Stated as T4 [NOS] with no other information on extension T4NOS T4NOS RE RE
820 OBSOLETE DATA CONVERTED V0200
See code 805

Further contiguous extension
ERROR: ERROR: ERROR: ERROR:
950 No evidence of primary tumor T0 T0 U U
999 Unknown; extension not stated
Primary tumor cannot be assessed
Not documented in patient record
TX TX U U
- For CS Extension codes 100-620 ONLY, the T category for AJCC 7 staging is assigned based on the value of CS Tumor Size, as shown in the Extension Size AJCC 7 Table for this schema. - For CS Extension codes 100-650 ONLY, the T category for AJCC 6 staging is assigned based on the value of CS Tumor Size, as shown in the Extension Size AJCC 6 Table for this schema.