This document discusses squamous cell carcinoma of the oral mucosa. It notes that squamous cell carcinoma comprises 90% of all oral malignant tumors. Strong risk factors include tobacco smoking, chewing, and drinking alcohol. Histologically, it can range from well-differentiated to undifferentiated. Prognosis is generally poor due to late detection and early lymph node metastasis, especially for tongue and soft palate cancers. The document also briefly mentions other less common oral cancers.

2. • malignant neoplasms of epithelial cells from
all three germ cell layers are called
carcinomas.

3. Squamous Cell (Epidermoid)
Carcinoma of bucal or oral mucosa
INCIDENCE. Squamous cell (epidermoid) carcinoma
comprises 90% of all oral malignant tumours and
5% of all human malignancies. The peak incidence
in the UK and the USA is from 55 to 75 years of age,
whereas in India it is from 40 to 45 years of age.
Oral cancer is a very frequent malignancy in India,
Sri Lanka and some Eastern countries, probably
related to habits of betel-nut chewing and reversed
Smoking.

4. ETIOLOGY.
Strong association:
i) Tobacco smoking and tobacco chewing causing leukoplakia is the
most important factor as discussed above.
ii) Chronic alcohol consumption.
iii) Human papilloma virus infection, particularly HPV 16, 18 and 33
types.
Weak association:
i) Chronic irritation from ill-fitting denture or jagged teeth.
ii) Submucosal fibrosis as seen in Indians consuming excess of chillies.
iii) Poor orodental hygiene.
iv) Nutritional deficiencies.
v) Exposure to sunlight (in relation to lip cancer).
vi) Exposure to radiation.
vii) Plummer-Vinson syndrome, characterised by atrophy of the upper
alimentary tract.

5. MORPHOLOGIC FEATURES
i) Ulcerative type—is the most frequent type and is characterised by
indurated ulcer and firm everted or rolled edges.
ii) Papillary or verrucous type—is soft and wart-like growth.
iii) Nodular type—appears as a firm, slow growing submucosal nodule.
iv) Scirrhous type—is characterised by infiltration into deeper
structures.
All these types may appear on a background of leukoplakia or
erythroplasia of the oral mucosa. Enlarged cervical lymph nodes may
sometimes be present.
Histologically, squamous cell carcinoma ranges from well-
differentiated keratinising carcinoma to highly undifferentiated
neoplasm. Changes of epithelial dysplasia are often present in the
surrounding areas of the lesion. Carcinoma of the lip and intraoral
squamous carcinoma are usually always well differentiated.

7. Oral mucosa showing epithelial dysplasia progressing to invasive
squamous cell carcinoma. There is keratosis, irregular stratification
cellular pleomorphism, increased and abnormal mitotic figures and
individual cell keratinisation, while a few areas show superficial
invasive islands of malignant cells in the subepithelial soft tissues

8. Carcinoma of the lip has a more favourable prognosis due to
visible and easily accessible location and less frequent
metastasis to the regional lymph nodes. However, intraoral
squamous carcinomas have poor prognosis because they are
detected late and metastasis to regional lymph nodes occur
early, especially in the case of carcinoma of tongue and soft
palate. Verrucous carcinoma, on the other hand, is composed
of very well-differentiated squamous epithelium with minimal
atypia and hence has very good prognosis.
OTHER MALIGNANT TUMOURS
Other less common malignant neoplasms which may be
encountered in the oral cavity are: malignant melanoma,
lymphoepithelial carcinoma,

9. Carcinoma of Oesophagus
ETIOLOGY. :
1. Diet and personal habits:
i) Heavy smoking
ii) Alcohol consumption
iii) Intake of foods contaminated with fungus
iv) Nutritional deficiency of vitamins and trace elements.
2. Oesophageal disorders:
i) Oesophagitis (especially Barrett’s oesophagus in adenocarcinoma)
ii) Achalasia
iii) Hiatus hernia
iv) Diverticula
v) Plummer-Vinson syndrome.
3. Other factors:
i) Race—more common in the Chinese and Japanese than
in Western races; more frequent in blacks than whites.
ii) Family history—association with tylosis (keratosis palmaris et plantaris).
iii) Genetic factors—predisposition with coeliac disease, epidermolysis bullosa, tylosis.
iv) HPV infection—is the recent addition in etiologic factors.

11. Squamous cell carcinoma oesophagus. A, Gross appearance.
The tubular structure has thick muscle in its wall and has
longitudinal mucosal folds. There is a concentric circumferential
thickening in the middle (arrow) causing narrowing of the
lumen (arrow). The mucosal surface is ulcerated.
B, Photomicrograph shows whorls of anaplastic squamous cells
invading the underlying soft tissues.

12. Grossly, 3 types of patterns are recognised:
i) Polypoid fungating type—is the most common form. It
appears as a cauliflower-like friable mass protruding into the
lumen.
ii) Ulcerating type—is the next common form. It looks grossly
like a necrotic ulcer with everted edges iii) Diffuse infiltrating
type—appears as an annular, stenosing narrowing of the lumen
due to infiltration into the wall of oesophagus.
Microscopically, majority of the squamous cell carcinomas
of the oesophagus are well-differentiated or moderately
differentiated
Prickle cells, keratin formation and epithelial pearls are
commonly seen. However, non-keratinising and anaplastic
growth patterns can also occur. An exophytic, slow-growing,
extremely welldifferentiated variant, verrucous squamous cell
carcinoma, has also been reported in the oesophagus.

13. ADENOCARCINOMA. Adenocarcinoma of the
oesophagus constitutes less than 10% of primary
oesophageal cancer. It occurs predominantly in men in
their 4th to 5th decades. The common locations are
lower and middle third of the oesophagus. These
tumours have a strong and definite association with
Barrett’s oesophagus in which there are foci of gastric
or intestinal type of epithelium.
Grossly, oesophageal adenocarcinoma appears as
nodular, elevated mass in the lower oesophagus.

14. Grossly, oesophageal adenocarcinoma appears as nodular,
elevated mass in the lower oesophagus.
Microscopically, adenocarcinoma of the oesophagus can have 3
patterns:
i) Intestinal type—is the adenocarcinoma with a pattern similar to
that seen in adenocarcinoma of intestine or stomach.
ii) Adenosquamous type—is the pattern in which there is an
irregular admixture of adenocarcinoma and squamous cell
carcinoma.
iii) Adenoid cystic type—is an uncommon variety and is akin to
similar growth in salivary gland i.e. a cribriform appearance in an
epithelial tumour.
Adenocarcinoma of the oesophagus must be distinguished from
denocarcinoma of the gastric cardia. This is done by identifying
normal oesophageal mucosa on distal as well as proximal margin
of the tumour.

15. OTHER CARCINOMAS. Besides the two main histological types of
oesophageal cancer, a few other varieties are occasionally
encountered. These are as follow:
i) Mucoepidermoid carcinoma is a tumour having characteristics of
squamous cell as well as mucus-secreting
carcinomas.
ii) Malignant melanoma is derived from melanoblasts in the
epithelium of the oesophagus.
iii) Oat cell carcinoma arises from argyrophil cells in the basal layer
of the epithelium.
iv) Undifferentiated carcinoma is an anaplastic carcinoma which
cannot be classified into any recognisable type of carcinoma.
v) Carcinosarcoma consists of malignant epithelial as well as
sarcomatous components.
vi) Secondary tumours rarely occur in the oesophagus from
carcinomas of the breast, kidney and adrenals.

16. SPREAD.
i) Local spread.
ii) Lymphatic spread.
iii) Haematogenous spread.

17. Gastric carcinoma

18. ETIOLOGY
1. H. pylori infection.
2. Dietary factors.
i) Occurrence of gastric cancer in the region of gastric canal
(i.e. along the lesser curvature and the pyloric antrum) where
irritating foods exert their maximum effect.
ii) Populations consuming certain foodstuffs have high risk
of developing gastric cancer e.g. ingestion of smoked foods,
high intake of salt, pickled raw vegetables, high intake of
carcinogens as nitrates in foods and drinking water, nitrites
as preservatives for certain meats.
iii) Tobacco smoke, tobacco juice and consumption of alcohol

19. 3. Geographical factors. There are geographic variations in
the incidence of gastric cancer. Japan, Chile and Italy have the
highest recorded death rate from gastric cancer.
4. Racial factors. incidence is higher in Blacks, American
Indians, Chinese in Indonesia, North Wales than other parts of
Wales.
5. Genetic factors. common in individuals with blood group O.
6. Pre-malignant changes in the gastric mucosa.
i) Hypo- or achlorhydria in atrophic gastritis of gastric mucosa
with intestinal metaplasia.
ii) Adenomatous (neoplastic) polyps of the stomach.
iii) Chronic gastric ulcer (ulcer-cancer), and its association with
achlorhydria.
iv) Stump carcinoma in patients who have undergone partial
gastrectomy.

20. MORPHOLOGIC FEATURES
I. Early gastric carcinoma (EGC).
Histologically, EGC is a typical glandular adenocarcinoma,
usually well-differentiated type.
II. Advanced gastric carcinoma, which has 5 further major
gross subtypes:
i) Ulcerative carcinoma
ii) Fungating (Polypoid) carcinoma
iii) Scirrhous carcinoma (Linitis plastica)
iv) Colloid (Mucoid) carcinoma
v) Ulcer-cancer

21. A, Ulcerative carcinoma stomach. The luminal surface of the stomach in the region of pyloric
canal shows an elevated irregular growth with ulcerated surface and raised margins. B,
Malignant cells forming irregular glands with stratification are seen invading the layers of the
stomach wall. C, Linitis plastica. The wall of the stomach in the region of pyloric canal is
markedly thickened and fibrotic while the mucosal folds are lost. D, Microscopy shows
characteristic signet ring tumour cells having abundant mucinous cytoplasm positive for
mucicarmine (inbox). The stroma is desmoplastic.

23. Colorectal carcinoma
CLINICAL FEATURES. Clinical symptoms in colorectal
cancer appear after considerable time. These are as
follows:
i) Occult bleeding (melaena)
ii) Change in bowel habits, more often in left-sided
growth
iii) Loss of weight (cachexia)
iv) Loss of appetite (anorexia)
v) Anaemia, weakness, malaise.

24. Gross appearance of colorectal carcinoma. A, Right-sided growth—fungating polypoid
carcinoma showing cauliflower-like growth projecting into the lumen. B, Left-sided growth—
napkin-ring configuration with spread of growth into the bowel wall.

25. Colonic adenocarcinoma. A, Moderately differentiated. B, Mucin-secreting adenocarcinoma.