PATHOLOGY OF NASOPHARYNX, HYPOPHARYNX AND LARYNX
INFLAMMATORY LESIONS
 acute pharyngitis - manifests itself as sore throat
-morphologic changes are mild- accompanied by cold
-more severe forms of pharyngitis are associated with tonsillitis or acute
pharyngotonsillitis
-marked hyperemia, larger amounts of exudate
pathogenesis:
-most often caused by beta-hemolytic streptoccoci and
adenovirous infections
acute pharyngitis may be also a component of infectious mononucleosis (caused
by EB-virus )
-pharyngitis ulcerosa- may be caused by herpes simplex and coxsackie viruses
 acute laryngitis -caused by allergic insults, but also may be associted with
acute pharyngitis and common cold, caused by the same infectious agents
in small children- laryngeal inflammatory reaction (edema) may narrow the
airways to that extent that it may cause acute respiratory failure
 diphteric laryngitis- caused by corynebacterium diphteriae
-that causes acute membranous inflammation of the larynx, pharynx and
trachea- bacteria produce large amounts of exotoxins- that result in
1- necrosis of the mucosal membrane epithelium- covered by dense
fibrinopurulent exudate- diphteric membrane- may be aspirated- or may cause
obstruction of major airways
2- bacterial exotoxins may result in diphteric myocarditis,
peripheral neuropathy etc.
TUMORS OF NASOPHARYNX
1. The most common type is nasopharyngeal carcinoma- remarkable for the
striking geographical differences in its incidence and association with the EBV
(Epstein-Barr virus)
Synonyms- Schmincke’s lymphoepithelioma
Epidemiology:
-nasopharyngeal carcinoma shows a distinct racial and geographical
distribution and multifactorial etiology
-it is rare in most parts of the world (about 0,6% of all cancers), there
are certain populations for which the incidence is higher, such as native Chinese,
southeast Asians (Thailand, Filippines, and Vietnam), as well as native population
of Arctic region (Canada, Alaska), etc.
-in general, in migration from high risk to low risk areas, the incidence is
about the same, but tends to decrease in successive generations
-2-3-fold more common in men, peak age 4th-5th decades
Etiology:
-specific geographical and demographic distribution reflects a
combination of genetic susceptibility and infection by EBV with other
environmental factors, such as dietery in disease cause
-the near consistent association of EBV eith nasopharyngeal carcinoma
indicates a probable oncogenic role of EBV
-the evidence include: presence of EBV-DNA or RNA in all cases of NC,
raised levels of antibodies against EBV in most patients with NC, presence of
EBV in precursor lesions,
-environmental factors, include diet- salted fish, cigarette smoking,
chemical fumes and dust, and prior radiation
Symptoms:
-neck mass (46%) from early metastases to lymph nodes, nasal bleeding
obstruction and discharge, headache
Morphology: malignant epithelial tumor- histologically three major variants
include: keratinizing squamous cell carcinoma (SCC), nonkeratinizing squamous
cell carcinoma, and basaloid squamous cell carcinoma, associated with abundant
lymphocytic infiltration in the tumor stroma
-undifferentiated nonkeratinizing SCC- most common type,
characterized by syncytial growth pattern of tumor cells- large epithelial cellsresemble transitional cells of the urothelium- prominent large clear nuclei,
cytoplasm indistinctive, large amounts of reactive mature lymphocytes in the
tumor stroma
clinical course:
highly malignant tumor- locally aggressive with rapid spread to cervical lymph
nodes- often first clinical presentation of the tumor -is cervical
lymphadenopathy
- distant metastases are common- the tumor has good radiosensitivity
2. nasopharyngeal angiofibroma
-benign, highly cellular and richly vascularized mesenchymal neoplasm that
involves the nasopharynx in males between 10 and 25 years of age
- it represents about 1% of all nasopharyngeal tumors
- gentic susceptibility-there is association with FAP (familiar adenomatous
polyposis syndrome)
- cause is unknown, but there are androgen receptor in tumor cells- may be
testosteron dependent-adolescent men are affected
-grossly- polypoid mass protruding from the posterior wall of the nasopharynx
-histologically- composed of loose fibrous stroma with abundant blood vessels
symptoms and prognosis:
patiens usually present with nasal obstruction, epistaxi, nasal discharge, facial
deformity, headaches, dyspnoe
the tumor expands in all directions, potential aggressive behavior, the tumor is
benign, but often recurrent (20%), surgery alone succesful in most cases, in
large recurrent tumors radiation
PSEUDOTUMORS AND TUMORS OF HYPOPHAYNX, LARYNX AND TRACHEA
By far the most common and important tumor is squamous cell carcinoma-clearly
related to tabacco smoking
Epidemiology:
Laryngeal and hypopharyngeal SCC occur most frequently in 6th to 7th decades
Incidence:
SCC comprises about 95% of laryngeal malignancies- majority originate from
glottic and supraglottic regions
-the incidence is high in men in central and southern Europe, Brazil and
aminy Blacks in the United States
-low incidence in women, particularly Africa and East Asia
-the incidence of laryngeal and hypopharyngeal SCC is increasing in much of the
world, both in men and women
Etiology:
Most cases of laryngeal cancer in Western countries are related to smoking and
alcohol abuse-avoiding of both alcohol and cigarettes could present 90% of
laryngeal cancer
-conflicting evidence implicating HPV 16 in laryngeal SCC- minor causative
role
-minor role in nonsmokers- gastroesophageal reflex
-no strong evidence of genetic factors in laryngeal carcinogenesis
-environmental influences- asbestos exposure- may play a role in
pathogenesis
Histologic findings: in 95% -squamous cell carcinoma
rarely-adenocarcinoma, adenoid cystic carcinoma- arising in mucous glands
EPITHELIAL PRECURSOR LESIONS
-carcinoma arises within the laryngeal epithelium- laryngeal dysplasia -is
preneoplastic lesion - laryngeal intraepithelial neoplasia- LIN - carcinoma in situ
precursor lesions are defined as altered epithelium with an increased probability
of progression to SCC
-altered epithelium show spektrum of cytological and structural changes,
that are classified to categories (according to WHO classification 2005):
-squamous cell hyperplasia
-mild dysplasia
-moderate dysplasia
-severe dysplasia
-carcinoma in situ
-with increasing risk of progression, most patients with precursor lesions give a
history of symptoms, such as hoarseness, sore throat, throat irritation, chronic
cough
macroscopy of precursor lesions:
-clinically diverse appearance, presenting as leukoplakia (white patches),
chronic hyperplastic laryngitis, or rarely erythroplakia (red patches)
-the lesions are commonly more diffuse with thickened appearance- on
vocal cords
histopathology of precursor lesions:
-epithelium is generally thickened with variable degree of cellular atypia
and irregularities in maturation and stratification-dysplasia
-some precursor lesions are self-limited, other persist and progress to
SCC
-histologic severity of dysplasia is predictive
ADVANCED INVASIVE SCC OF LARYNX- macroscopically - gray ulcerated
mucosal plaque
clinical features: -persistent hoarseness is the most typical presentation
at presentation- most carcinomas are confined to the larynx- prognosis is
better
laryngeal carcinomas in advanced stage- pain, dysphagia, haemoptysis
cause of death-in most patients with laryngeal ca- infections of respiratory
tract, not a dissemination
OTHER TUMORS AND PSEUDOTUMORS OF LARYNX
1-vocal cord nodule (polyp) -polypoid protrusion with smooth surface
located on the vocal cords- results from chronic irritation
-it occurs in heavy smokers, singers, teachers (singer nodes)
histology: -the nodules are composed of fibrous stroma-covered by mature
stratified squamous epithelium, there are recent or organized hemorrhages in
the stroma, edema and inflammatory cells
2-laryngeal papilloma -benign neoplasm, located on the true vocal cords
- composed of soft finger-like multiple protrusions supported by fibrovascular
stroma- covered by mature stratified epithelium, caused by HPV infection
-the tumors can be multiple and recur
-when located on the free edge of the cord- ulceration may occur -resulting in
hemoptysis and exuberant epithelial regeneration- may mimic carcinoma
etiology:
HPV-6 and 11 are the most frequent genotypes, rarely HPV of other types
3- juvenile laryngeal papillomatosis
in adults- the papilloma is usually single- but in children more often-multiple
juvenile laryngeal papillomatosis- caused by HPV (human papilloma virus 6 and 11)
never become malignant- often spontaneous regression