Page 530 - Textbook of Pathology, 6th Edition

514 stratified epithelium which is continued on to the external inflammatory cell infiltrate, vascular proliferation and
layer of the tympanic membrane. The tympanic membrane fibrosis.
has middle layer of elastic fibrous tissue and the inner layer
of mucous membrane and is supported around the periphery
by the annulus. MISCELLANEOUS CONDITIONS
The middle ear consists of 3 parts—the uppermost CAULIFLOWER EAR. This is an acquired deformity of the
portion is the attic, the middle portion is mesotympanum, and external ear due to degeneration of cartilage as a result of
the lowermost portion is the hypotympanum. Besides, the repeated trauma as occurs in boxers and wrestlers.
middle ear has an opening, eustachian tube, the mastoid
antrum and cells, and the three ossicles (the malleus, incus Histologically, there is destruction of cartilage forming
and stapes). The middle ear is lined by a single layer of flat homogeneous matrix (chondromalacia) and fibrous
ciliated and nonciliated epithelium. replacement.
The inner ear or labyrinth consists of bony capsule
embedded in the petrous bone and contains the membranous OTOSCLEROSIS. This is a dystrophic disease of labyrinth
labyrinth. The bony capsule consists of 3 parts—posteriorly of the temporal bone. The footplate of stapes first undergoes
three semicircular canals, in the middle is the vestibule, and fibrous replacement and is subsequently replaced by sclerotic
anteriorly contains snail-like cochlea. bone. The exact etiology is not known but the condition has
Besides the function of hearing, the stimulation of familial preponderance and autosomal dominant trait. It is
vestibular labyrinth can cause vertigo, nausea, vomiting and seen more commonly in young males as a cause for sensori-
nystagmus. neural type of deafness.

INFLAMMATORY LESIONS TUMOURS AND TUMOUR-LIKE LESIONS
OTITIS MEDIA. This is the term used for inflammatory Tumours and tumour-like conditions are relatively more
involvement of the middle ear. It may be acute or chronic. common in the external than the middle and inner ear. The
The usual source of infection is via the eustachian tube and lesions seen in the external ear are similar to those seen in
the common causative organisms are Streptococcus the skin e.g. tumour-like lesions such as epidermal cyst; benign
pneumoniae, Haemophilus influenzae and β-Streptococcus tumours like naevi and squamous cell papilloma; and
haemolyticus. Otitis media may be suppurative, serous or malignant tumours such as basal cell carcinoma, squamous
SECTION III
mucoid. Acute suppurative otitis media (SOM) clinically cell carcinoma and malignant melanoma. However, tumours
presents as tense and hyperaemic tympanic membrane along and tumour-like lesions which are specific to the ear are
with pain and tenderness and sometimes mastoiditis as well. described below. These include the following:
Chronic SOM manifests clinically as draining ear with In the external ear—aural (otic) polyps and cerumen-
perforated tympanic membrane and partially impaired gland tumours.
hearing. Serous or mucoid otitis media refers to non- In the middle ear—cholesteatoma (keratoma) and jugular
suppurative accumulation of serous or thick viscid fluid in paraganglioma (glomus jugulare tumour).
the middle ear. These collections of fluid are encountered In the inner ear—acoustic neuroma.
more often in children causing hearing problems and occur AURAL (OTIC) POLYPS. Aural or otic polyps are tumour-
due to obstruction of the eustachian tube. like lesions arising from the middle ear as a complication of
Systemic Pathology
RELAPSING POLYCHONDRITIS. This is an uncommon the chronic otitis media and project into the external auditory
autoimmune disease characterised by complete loss of canal.
glycosaminoglycans resulting in destruction of cartilage of
the ear, nose, eustachian tube, larynx and lower respiratory Histologically, they are composed of chronic inflamma-
tract. tory granulation tissue and are often covered by
metaplastic squamous epithelium or pseudostratified
columnar epithelium.
Histologically, the perichondral areas show acute
inflammatory cell infiltrate and destruction and vasculari- CERUMEN-GLAND TUMOURS. Tumours arising from
sation of the cartilage. Late stage shows lymphocytic cerumen-secreting apocrine sweat glands of the external
infiltration and fibrous replacement.
auditory canal are cerumen-gland adenomas or cerumen-
gland adenocarcinomas and are counter-parts of sweat gland
CHONDRODERMATITIS NODULARIS CHRONICA tumours (hideradenoma and adenocarcinoma) of the skin
HELICIS. This condition involves the external ear discussed in Chapter 26. Both these tumours may invade the
superficially and presents as a ‘painful nodule of the ear’. temporal bone.
The skin in this location is in direct contact with the cartilage
without protective subcutaneous layer. CHOLESTEATOMA (KERATOMA). This is a post-
inflammatory ‘pseudotumour’ found in the middle ear or
Histologically, the nodule shows epithelial hyperplasia mastoid air cells. There is invariable history of acute or
with degeneration of the underlying collagen, chronic chronic otitis media. A marginal perforation is generally