Paranasal Sinus Cancer
The paranasal sinuses are small hollow spaces around the nose. There
are several paranasal sinuses. A pair of frontal sinuses present
above the nose, in the forehead. Largest of all, the maxillary sinus,
present in the upper jaw one either side of nose and below the eyes.
The ethmoid sinuses are present between the two eyes and the sphenoid
sinuses lie behind the nose.
The sinuses
and nose are lined with cells that produce mucous, which keeps the
nose moist; the sinuses are also a space through which the voice
can echo to make sounds when a person talks or sings. The nasal
cavity is the passageway just behind the nostrils through which
air passes on the way to the throat during breathing.
Malignant tumours
of the sinonasal tract are very uncommon, occurring in approximately
1 in 100,000 people and representing only 3% of all head and neck
cancers. The incidence in males is twice that of females, due to
the fact of a greater occupational exposure to certain carcinogens.
These tumours most frequently develop during the 5th to 7th decades.
About 80% of paranasal sinus cancers originate in the maxillary
sinus. However, because a majority of them present at advanced stages,
it is sometimes difficult to determine the exact primary site of
the tumour.
Risk
Factors:
- Tobacco smoking
- Occupational
exposure of carcinogens.
There is a significant
high incidence of adenocarcinoma of the paranasal sinus among the
furniture workers with chronic exposure to wood dust and in leather
tanning industry. Nickel and chromium refining process have been
implicated in the development of squamous cell and anaplastic cancer.
Snuff and thorium dioxide, a radiological contrast agent, also have
been associated with an increased incidence of sinonasal cancer.
Clinical
Picture:
- Nasal obstruction
that does not clear
- Nasal discharge
- Headache
or pain in the sinus region
- Pain in
the upper teeth
- Problems
with dentures
- Swelling
or trouble with the eyes
- A lump or
sore that does not heal inside the nose
- Swelling
in the cheek
Because these
symptoms are similar to those of chronic sinusitis, there is always
a big delay between the onset of symptoms and final diagnosis. As
a result, most patients usually present at late stages.
Diagnosis:
Anyone with
such symptoms requires careful evaluation and examination with fibreoptic
endoscopy. If an abnormal tissue is found, the doctor need to cut
out a small piece and look at it under the microscope to see if
there are any cancer cells. This is called a biopsy. Sometimes the
doctor will need to cut into sinus to do a biopsy. CT scan helps
to find out the extent of the mass, bone destruction and to find
out whether it is involving the eye or extending intracranially.
MRI scan gives better picture of intracranial extension, orbital
involvement; perineural spread (adenoid cystic carcinoma spreads
along the nerve) and differentiates an obstructed sinus with fluid
collection from a space-occupying lesion.
Treatment:
Currently most of the early carcinomas of the sinus are treated
by surgery alone, whereas large lesions are treated by a combination
of surgery and radiotherapy.
Surgery:
A number of
surgical procedures available viz.
- Partial
Maxillectomy
- Total Maxillectomy
- Total Maxillectomy
with orbital exenteration
- Medial
Maxillectomy
- Craniofacial
resection
In partial maxillectomy,
only the lower part of the maxillary antrum, bearing the teeth was
removed. Whereas in total maxillectomy whole of maxilla (upper jaw)
is removed. This leaves a defect in the hard palate, which makes
it difficult to talk and eat. This problem can be overcome by wearing
a prosthesis made by the dentist. Since teeth can be fit into this
prosthesis, it gives a good functional and cosmetic result. This
prosthesis needs removal and cleaning by the patient. The other
technique is to close the defect in the palate permanently using
micro vascular flaps by the plastic surgeon. In medial maxillectomy,
only the lateral wall of the nose is removed. Tumours reaching the
skull base or extending into the infratemporal fossa were considered
inoperable and therefore incurable. With the current techniques
of skull base surgery, these tumours are removed safely and completely
in selected centers like ours. This requires a team approach wherein
ENT-Head & Neck surgeon, Neurosurgeon and Plastic surgeon join
together to remove these skull base tumours safely and reconstruct
in such a way to bring function as well as appearance as close to
normal as possible.
Questions
patients should ask before deciding about the treatment:
- What are
my treatment options?
- What are
the risks and benefits for each of my treatment options?
- How will
treatment affect my everyday activity? How long?
- How often
will I need to return?
- Has my doctor
explained various surgical options to my satisfaction?
- Have I been
seen by a surgeon who has expertise with removal of cancer, as
well as, with reconstruction?
- Have I seen
by a surgeon, radiation oncologist, prosthodontist and dentist?
- Do I know
all I need to know about prostheses and prosthetic techniques?
- How often
has the surgeon performed the kind of surgery he is recommending?
- What will
the surgical site look like after healing?
- Will my
appearance and physical capabilities be affected? If so how?
- Should I
consider combination therapy (both surgery and radiation therapy)?
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