| Paranasal Sinus Pathology The Paranasal sinuses like every other organ or structure are susceptible to pathology. Pathologiy are damages to organs and structures of the body. Pathology to the Paranasal Sinuses include: Sinusitis, Mucocele, Nasal Polyps, Paranasal sinus tumour, Presence of foreign body, and Trauma.  |
SINUSITIS:
Also known as Rhinosinusitis is the inflammation of the mucous membrane that lines the sinuses resulting in symptoms.
Sinusitis ranges from Acute to Chronic stages, the former lasting below 4 weeks and the latter over 12weeks. Acute Sinusitis may present with no symptoms whereas Chronic Sinusitis is evident of symptoms. Common symptoms include thick nasal mucous, and facial pain. Other signs and symptoms may include; sore throat, fever, headaches, a poor sense of smell, and cough.
Infection, allergies, air pollution, or structural problems in the nose can cause Sinusitis.
Infections are mostly viral and bacterial. Others can be due to fungus.
The Maxillary Sinus is susceptible to sinusitis via infection as the conic elevation related to the roots of the second upper molar teeth project through the floor of each Maxillary Sinuses. This conic elevation thus may bring infection into the Maxillary sinuses.
The Frontal, Ethmoid, and the Maxillary Sinuses are also susceptible to Sinusitis when there is a result of obstruction in drainage within the Osteomeatal Complex.
As seen in the image above, the large maxillary sinus drains through the infidibulum passageway down the middle nasal meatus (Ucinate Process) into the inferior middle nasal meatus. The ethmoid bulla receives drainage from the frontal and ethmoid sinus cells, which then drains down the through the middle nasal meatus into the inferior nasal meatus where it exits the body through the exterior nasal orifice.
Obstruction in the Ucinate process thus results in infection the Sinuses.
Inflammatory response to allergy, bacterial, and viral infections also results in sinusitis in the Sphenoid Sinus.
BACTERIA:
This is the most common pathology in Sinusitis. Staphylococci have been reported as the most common pathogen, others include Streptococcus pneumonia, Aerobic gram-negative bacteria, and Anaerobes.
The presenting symptom of bacteria induced Sinusitis may be indistinguishable from fungal and mucocele.
FUNGI:
Fungal Sinusitis can be broadly classified as Invasive and non-Invasive Fungal Sinusitis. They can be distinguished by the presence of fungi invasion in Sinus tissue (via Histopathological study).
Non-Invasive Fungal Sinusitis: Aspergilloma; when there is a dense conglomeration of hyphae or clay-like material within the Sinus cavity leading to mucosal inflammatory response and evidence of tissue or vascular invasion.
Invasive Fungal Sinusitis: Here, mycotic organisms infiltrate the Sinus mucosa. Although this is rare as in most cases the Patient’s immunological status is normal or only mildly abnormal.
This disease invasion involves adjacent structures; Cranial nerve palsies or Pituitary involvement.
CAN CT SCAN CAUSE DAMAGE TO THE BRAIN CELLS?
VIRUS:
Vast majority of Sinusitis episodes are caused by viral infection. Most upper respiratory tract infections are caused by Rhinovirus. Coronavirus, influenza A and B, adenovirus are also causative agents. Rhinovirus, Influenza, and Parainflenza viruses are the primary pathogens in 3% of Patients with Acute Sinusitis.
Viral upper respiratory tract infections are the most important risk factor for the development of acute bacterial Sinusitis. Approximately 90% of Patients who have viral upper respiratory tract imfections have Sinus involvements.
MUCOCELE:
Mucoceles are benign encapsulated lesions filled with mucous and lined by epithelium. They are expandsile and locally destructive with the ability to reabsorb bone, causing erosions of the bony walls of the Sinus.
Mucocele is quite common with the Sphenoid Sinus than with other Paranasal Sinuses. It represents up to 20% of all Paranasal Sinus Mucoceles. The pathophysiology of this lesion is still unknown but may be due to obstruction of the glandular structures or cystic development from embryonic epithelial residues. Radiation exposure at head and neck area has also been postulated.
Clinical Symptoms may mimic Neoplasm. Thus, visual loss is more common.
Sphenoid Sinus Mucocele may be asymptomatic. Patients with Sphenoid Sinus Mucocele may become symptomatic when the Mucocele compresses or displaces structures around the Sphenoid Sinus.
POLYPS:
They are soft, painless, noncancerous growth on the lining of the nasal passages or sinuses. They hang down like teardrops or grapes.
Nasal polyps result from chronic inflammation and are associated with asthma, recurring infections, allergies, drug sensitivity or certain immune disorders.
Nasal polyps are more common in adults. Small nasal polyps may not cause symptoms but larger growths or groups of nasal polyps can block the nasal passages or lead to breathing problems, a lost sense of smell, and frequent infection. Other signs and symptoms are; a running nose, post nasal drip, lost sense of taste, facial pain or headache, pain in the upper teeth, snoring etc.
PARANASAL SINUS TUMOUR:
This is a cancer that has grown inside the sinuses. This tumour can begin in the cells of the membranes, bones or nerves that line the area. They are often not suspected until the tumour had spread.
CAUSES;
Not all Paranasal sinus tumours have known causes, but possible causes can be; exposure to industrial chemicals, infection with HPV (Human Papilloma Virus), exposure to radium, cigarette smoking etc.
Signs & Symptoms may show; blockage in sinuses, changes in voice or breathing, reduced sense of smell, headache, numbness or pain the ear, face or teeth, teeth may become loose, pus draining from the nose, postnasal drip, frequent nose bleeding, bulging eye, loss or change in vision, trouble opening the mouth etc.
FOREIGN BODY:
This is very rare and most of cases are encountered in the maxillary sinuses. They may be organic or inorganic and can enter the maxillary sinus through the oro-antral fistula. This fistula is formed by a break in the bony segment of the maxillary sinus floor and usually arises subsequent to maxillary premolar and molar extraction. The foreign bodies make the patient susceptible to headache and lesion (in the area affected).
TRAUMA
Trauma to the superior and middle thirds of the face can often lead distruption in the bony framework of the paranasal sinuses, which in turn leads to paranasal sinus fractures involving one or more paranasal sinuses.
Furthermore, forces greater than paranasal sinus resistance may result in traumatic brain injury.
Facial trauma results due to; assaults accidents etc. Signs and symptoms ranges from facial pain (headache) to facial swelling etc.
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