This document summarizes several variants of oral squamous cell carcinoma (SCC), including verrucous carcinoma, basaloid SCC, and sarcomatoid carcinoma. It describes the histological features and sites of involvement for each variant. Key microscopic findings are outlined, such as the prominent keratin layer and pushing margins seen in verrucous carcinoma. Diagnostic criteria and differential diagnoses for each variant are also provided. The document additionally reviews adenocarcinoma subtypes seen in the oral cavity and describes patterns of bone and perineural invasion associated with oral cancers.

1. THE HISTOLOGY OF
ORAL CANCER

2. Varients of SCC of the upper
aerodigestive tract
• Conventional SCC with varying levels of differentiation
• Verrucous SCC
• Basaloid SCC
• Sarcomatiod SCC
• Adenosquamous SCC
• Adenoid SCC
• Papillary SCC
• Lympho-epithelial (nasopharyngeal- type ) carcinoma.

3. VERRUCOUS CARCINOMA
SITE :
• mucous membrane of head and neck (oral cavity and larynx )
• cutaneous surfaces in aero digestive tract, anogenital region and
lower extremities.
FEATURES
• May be both persistent and progressive that last for years.
• Appear suddenly or period of slow growth followed by rapid
enlargement.
• Associated with clinical leucoplakia which way be diffuse or focal.

4. MICROSCOPICALLY
 VC is based on locally invasive with papillary fons.
Composed of highly differentiated squamous epithelial cells.
Surface of lesion is usually covered by prominent keratin layer
arranged in compressed invagination folds
Continuity is maintained by filiform or broader processes of well
differentiated squamous cells.
These processes resembles “church spires “
Infiltrative margins are blunt “pushing” ones with good
circumscription.
There is associated inflammatory reactions in stroma consisting of
lymphocytes.

5. verrucous carcinoma showing enlarged bulb like Acantholytic
invaginations - giving it a "pushing margin" appearance

6. BASALOID SQUAMOUS CELL CARCINOMA
• Its an aggressive variant of squamous cell carcinoma.
• SITE : upper aero digestive tract, esophagus, anus uterine and
cervix.
• Base of tongue , pyriform sinus and supraglotic larynx with
metastasis to cervical lymph nodes.
• It manifests both deep and lateral invasion.
• Clinically : BSCC even when small , are usually hard and centrally
ulcerated with submucosal infiltration.

7. MICROSCOPICALLY :
 Its usually well to moderately well differentiated and invasive with severe
squamous dysplasia present.
 The growth pattern of basaloid cells is lobular, but can also be in cods or
trabeculae.
 Prominent mitotic activity.
DIFFERENTIAL DIAGNOSIS:
 Adenoid cystic carcinoma
 Small cell undifferentiated
carcinoma with neuroendocrine
differentiation.

8. SARCOMATIOD CARCINOMA
• It’s the most common ‘spindle-cell malignancies’ of upper airway and
digestive tract.
• SITE : mucosa of head and neck, larynx and oral cavity, Sino nasal tract,
pharynx and esophagus.
• Usually pedunculated or polypeptide masses, less often sessile or ulcero
infiltrative lesions.
• Size varies from 0.5 to 6 cm.
• Surface is extensively ulcerated and covered by fibrinonecrotic exudate
of varying thickness.

9. MICROSCOPICALLY
• Its usually demarcated and does not exhibit intermingling with spindle
cell component.
• Sarcomatous element mimic fibroscarcoma , synovial sarcoma,
leiomyosarcoma.
• The spindle cells are arranged in fasciculate myxomatous or streaming
growth pattern.
• Multinucleated giant cells are
common which may be accompanied
by metaplastic or malignant
osseocartilaginous foci.
• They May be richly or sparsely
mitotic.

10. ADENOSQUAMOUS CARCINOMA
It’s a ‘malignant tumor with features of both
adenocarcinoma and squamous cell carcinoma.
SITE : GIT , upper and lower respiratory tract, skin ,
genitourinary tract. Oral cavity (floor of the mouth,
tonsillar-palatine) ,larynx, and paranasal sinus.
Its undeniably an aggressive neoplasm with high
mortality rate after regional or distant metastases.

11. Histologically :
• Characterized by association of adenocarcinoma and squamous
cell carcinoma growing in separate or mixed patterns.
• Three basic types of cell types : basaloid , squamous, and
undifferentiated.
• D/D :
Mucoepidermoid
carcinoma.

12. ADENOID SQUAMOUS
CARCINOMA
• It is a neoplasm of skin and especially of sun exposed area
of head and neck.
• SITES : mucosal sites- vermilion border of lips , tongue,
oral mucosa , nasopharynx , Sino nasal tract and larynx.
Histologically
• It shows pseudo glandular features.
• Adenoid feature is initiated in basal layer of squamous
epithelium.
• Manifested by suprabasal clefting and acantholysis.
• Desmoplastic reaction – accessory finding.

13. Acantholytic squamous cell carcinoma resulting
in a pseudo-glandular appearance

14. HISTOLOGIC GRADING (woolger and Scott )
HISTOLOGIC
FEATURE
1 2 3 4
Degree of
keratinization
High , pearl
formation
Moderate Poor, single cells None
Nuclear
pleomorphism
Minimal Moderate Numerous Extreme
Mitotic activity 0-15 16-35 36-55 >55
Invasion pattern Pushing Brands Cord or island Single cells
Stage of invasion Borderline
Into lamina
propria
Into submucosa Into muscles
Stromal
lymphoplasmacytic
infiltrate
Continues
rim
Moderate,
large patches
Minimal , small
patches
absent

15. PERINEURALINVASION
• Considered as
ominous prognostic
sign- local
recurrence ,
regional lymph
node metastasis ,
dec survival.
• Carter et al –
tumor tends to
remain localized to
the terminal 1 or
2cm of the nerve.
MICROVASCULARINVASION
• Vascular
involvement
confined to single
vessel has a
decrease potential
for metastasis.
• Extensions into
large vessels is
extremely poor
prognostic
indicator.

16. BASIC TYPES OF INVOLVEMENT:
1. EROSIVE FORM :
• The bone recedes before a pushing tumor margin. E.g. :
Verrucous Carcinoma .
• There is loss of cortical continuity with a U-shaped or
scalloped excavation of medullary bone.
• Radiologically , there is well defined radiolucency with no
spicules of bone
2. INFILTRATIVE FORM :
• There is neoplastic spread into the cancellous bone.
• Radiographically , ill-defined and irregular lesion is seen.
3. This shows spread through bone marrow without any marked
destruction and minimal radiographic changes. E.g.: adenoid
carcinoma.
ORAL CARCINOMA AND MANDIBULAR MARGINS

17. The violated bone surface shows pitting and new bone formation 
crevices and pits contains vascular granulation tissue  through these
defects the carcinoma begins penetration.
The SCC enter medullary cavity through the upper border of the
mandible.  either through occlusal ridge / combination with lingual
or buccal plates.
Thus cortical bone defects in edentulous alveolus is principal route for
direct spread into the mandible.
Breached the cortex  extends vertically and laterally .
Size of carcinoma does not influence incidence of bone involvement
but proximity of tumor to bone does.
Spread of CA is always through cancellous bone and marrow spaces.
CA involving gingival margin has high incidence of bone involvement.
Presence of dentition influences nerve-related spread.

18. REFERENCE ORAL SITE MEASURMENT CONCLUSION
Fukano et
al.
Tongue Depth of
invasion
Depth > 5mm , increased risk of
cervical metastasis
Ragson et
al.
Oral
cavity/
oropharynx
Tumor thickness Thickness >5mm increased risk of
cervical metastasis
Brown et al. Floor of
mouth
Tumor thickness Thickness>2mm consideration of
electric treatment of neck
Urist et at. Buccal
mucosa
Tumor
thickness/Depth
of invasion
Tumors >6mm poor survival
Mohit-
Tabatabai
et al
Floor of
mouth
Tumor thickness N0 lesions more than 1.5mm thick,
elective neck dissection strongly
indicated
Spiro et al Tongue/Flo
or of mouth
Tumor thickness N0 lesions more than 2.0mm thick,
elective neck dissection appropriate.
TUMOR DEPTH/ THICKNESS AND CERVICAL LYMPH NODE METASASIS