Acute neck infections and neck cancers caused by pyriform sinus infection is usually overlooked and is very hard to detect at an early age. Pyriform sinus is the recess tissue lying between the trachea and the esophagus. Since there is a lot of open space in your neck, tumors can extensively grow before they present any symptoms. The pyriform sinus is located int the region of the neck known as HypoPharynx. Hypo means the lower part and Pharynx is the cavity running from your nose through your esophagus. It is divided into three sections namely:
- OroPharynx – This is the top part which includes the tonsils, tongue base and others.
- NasoPharynx – This is the nasal area.
- HypoPharynx – This is the lower area that includes the pyriform sinus, LaryngoPharynx and aryepiglottic fold.
The term “piriform”, also spelled as pyriform, means pear-shaped. It is the subsite of the hypopharynx. Distinguishing the two is important for treatment and staging of neck and head cancer. The pyriform sinus is also a place where food gets commonly trapped. In infants, if foreign materials get stuck in the piriform fossa, it can be nonsurgically retrieved. Injured pyriform sinus due to food, i.e., fish bone, can cause a feeling of stuck food in the throat. The pressure of the piriform sinus, most commonly on the left side causes acute thyroiditis in both adults and children.
Pyriform sinus infection can also cause hoarseness and may become permanent if not treated within a couple of months. Any defect, destruction or tampering of the pyriform sinus can affect the larynx adversely. Food and water trapped in the pyriform sinus can cause uncontrollable coughing and irritation. In hypopharyngeal cancer cases, the pyriform sinus is where tumors are mostly located (70%).
Pyriform sinus fistula is a pyriform sinus infection which usually involves the thyroid glands. It is an abnormality on the development of the 3rd or 4th branchial pouch. In childhood, it presents itself as an acute neck inflammation which involves the thyroid gland most of the time. Too prevent the reoccurrence of this pyriform sinus infection, prompt surgical treatment is essential. To attain proper diagnosis, ultrasound, Barium Oseophagraphy and Computed Tomograpy (CT) are used.
Neck infection caused by pyriform sinus fistula occurs commonly in children with a ratio of 10:7 male to female ratio. The fistula which originates from the pyriform sinus appears to get infected after a course of infection on the upper respiratory tract blamed on the accumulation of contaminated secretions in the fistulous tract and the pharynx. Depending on the course of the sinus tract, abscesses on the neck or supporative thyroiditis may develop as a result of pyriform sinus infection.
Another pyriform sinus infection is the thyroid abscess and suppurative thyroiditis which are both very rare. High resistance of the thyroid gland to infection is associated to factors such as: rich blood supply, high iodine level which inhibits the growth of bacteria, generous lymphatic drainage and protective and complete fibrous capsule. CT is an essential tool for the visualization of the sinus and fistulous tract to be used for the evaluation of the lesion and its extent. Accurate imaging facilitates proper diagnosis and appropriate treatment to prevent to infection from recurring.
Suppurative thyroiditis is also known as Acute Infectious Thyroiditis (AIT). Although the thyroid is very resistant to infections, it is still susceptible to various bacteria such as Staphylococcus aureus, Streptococcus epidermidis, Streptococcus pneumonia and Streptococcus pyogenes. Most commonly, AIT occurs on patients with previous thyroid disease such as thyroid cancer or Hashimoto’s thyroiditis. In children, the most common cause of AIT is due to congenital abnormality such as pyriform sinus fistula. Most frequently, pyriform sinus infection spreads to the thyroid through the fistula.
The rate of infection due to AIT is still low but due to the increase in the number of immune-compromised patients, AIT cases are rising over the years. AIT can also be caused by outside source contaminants such as: regional infection, repeated fine needle aspirates and perforation of the esophagus.
Symptoms of AIT may occur from 1-180 days, with 18 days average occurrence. It includes pain, fever and swelling. Suspected AIT patients should undergo tests to determine elevated levels of white blood cells ad ultrasound to show unilobular swelling. More invasive procedures such as fine needle aspiration may be performed based on the age and immune status of the individual. Infection caused by sinus fistula is determined through laryngoscopic examination or surgery.
Pyriform sinus infection also causes hypopharynx cancer. The hypopharynx extends from the hyoid bone plane to the cricoids cartilage. It has three parts which includes the pyriform sinus, postcricoid area and posterior pharyngeal wall. Cancer in this region does not show symptoms until in the later stage of the disease. Malignancies occurring in this region are mostly squamous cell carcinomas. These malignancies are associated to excessive tobacco smoking and alcohol use.
In the early stage of the disease, radiation alone gives satisfactory results. The advanced stage of this disease is best treated with surgery with a follow up postoperative radiation. Chemotherapy with radiation is now used to treat the advanced stage of Hypopharynx cancer. Symptoms of Hypopharynx cancer include pain, weight loss and dysphagia. Pain may be experienced on the local site of the cancer or on the ipsilateral ear. Vocal cord paralysis and hoarseness can be due to advanced cancer on the pyriform sinus. To confirm the diagnosis and determine the extent of cancer, biopsy and direct laryngopharyngoscopy is needed.
Radiation therapy can cure stage 1 and stage 2 cancers of the piriform sinuses. Esophagectomy and laryngopharyngectomy may be needed when the cancer arises or extends to the cervical esophagus. Hypopharyngeal reconstruction is possible with jejuna and tubed radial forearm free flaps.
Hypopharyngeal cancers mostly occur in the pyriform sinus (over 75%) while a few arise in the posterior pharyngeal wall (20%). Less than 5% are postcricoid cancers making them rare. Total laryngopharyngectomy is often entailed for surgical management of hypopharyngeal cancers due to their closeness to the larynx and their growth pattern. Pyriform sinus infection can be treated especially in its early stages.