Page 540 - Textbook of Pathology, 6th Edition

524 is lined by stratified squamous epithelium. The cyst wall
contains sebaceous glands, sweat glands, hair follicles and
other mature tissues.

B. BENIGN TUMOURS
Different parts of the mouth have a variety of mesodermal
tissues and keratinising and non-keratinising epithelium.
Therefore, majority of neoplasms arising from the oral tissues
are just like their counterparts in other parts of the body.
Some of the common benign tumours of the mouth are as
under:
SQUAMOUS PAPILLOMA. Papilloma can occur anywhere
in the mouth and has the usual papillary or finger-like
projections.
Microscopically, each papilla is composed of vascularised
connective tissue covered by squamous epithelium.
HAEMANGIOMA. Haemangioma can occur anywhere in
the mouth; when it occurs on the tongue it may cause
macroglossia. It is most commonly capillary type, although
cavernous and mixed types may also occur.
Figure 19.1 Fibrous epulis in gingival.
LYMPHANGIOMA. Lymphangioma may develop most
A. TUMOUR-LIKE LESIONS commonly on the tongue producing macroglossia; on the lips
producing macrocheilia, and on the cheek. Cystic hygroma
A number of proliferative lesions arising from the oral tissues is a special variety of lymphangioma occurring in children
are tumour-like masses which clinically may resemble on the lateral side of neck.
neoplasms. Some of these are as under:
FIBROUS GROWTHS. Fibrous growths of the oral soft Microscopically, lymphangioma is characterised by large
SECTION III
tissues are very common. These are not true tumours (unlike lymphatic spaces lined by endothelium and containing
intraoral fibroma and papilloma), but are instead lymph (Chapter 15).
inflammatory or irritative in origin. A few common varieties
are as under: FIBROMA. Although most common benign oral mucous
i) Fibroepithelial polyps occur due to irritation or chronic membrane mass is fibroma appearing as a discrete superficial
trauma. These are composed of reparative fibrous tissue, pedunculated mass, it appears to be nonneoplastic in nature.
covered by a thin layer of stratified squamous epithelium. It probably arises as a response physical trauma (discussed
ii) Fibrous epulis is a lesion occurring on the gingiva and is above).
localised hyperplasia of the connective tissue following
trauma or inflammation in the area (Fig. 19.1). Giant cell epulis
Systemic Pathology
is a variant seen more commonly in females as reactive
change to trauma; the lesion shows numerous osteoclast-like
giant cells and vascular stroma.
iii) Denture hyperplasia occurs in edentulous or partly
edentulous patients. The lesion is an inflammatory
hyperplasia in response to local irritation by ill-fitting denture
or an elongated tooth.
PYOGENIC GRANULOMA. This is an elevated, bright red
swelling of variable size occurring on the lips, tongue, buccal
mucosa and gingiva. It is a vasoproliferative inflammatory
lesion. Pregnancy tumour is a variant of pyogenic granuloma.
MUCOCELE. Also called mucous cyst or retention cyst, it is
a cystic dilatation of the mucous glands of the oral mucosa.
The cyst often ruptures on distension and incites inflam-
matory reaction due to mucous extravasation (Fig. 19.2).
RANULA. It is a large mucocele located on the floor of the
mouth. The cyst is lined by true epithelial lining.
DERMOID CYST. This tumour-like mass in the floor of the Figure 19.2 Mucous retention cyst (mucocele). There is inflamma-
mouth represents a developmental malformation. The cyst tory reaction around extravasated mucus.