Introduction:
Lymphoid tissues are composed of lymphocyte cells. Lymphocytes fight white blood cells found even in the oral cavity and the head and neck region. The bone marrow and the thymus are the body's main points of lymphoid tissue. Apart from these sites, lymphocyte cell aggregates can also be found in the lymph nodes, spleen, MALT (mucosa-associated lymphoid tissue), and NALT (nasopharynx-associated lymphoid tissue). Many people often wonder about the function of lymphocyte cells and why developmental disturbances or anomalies are commonly observed in them. The lymphocytes are white blood cells primarily involved in the immune response and regulation in our body. These cells are not just meant for mediating an immune response or reaction to bodily infections, trauma, or cancers, but they also moderate the cells that can fight off cancer-forming or cancer-progressing cells.
What Are Developmental Disturbances of Oral Lymphoid Tissues?
Developmental disturbances may occur in any part of the body, so they are even associated with the oral cavity and can be caused by environmental or genetic factors. These disturbances can occur at any age group in life, but they most commonly occur in the second to third decade of life or in the age group between 20 and 40 years. In the oral cavity and in the head and neck, lymphoid tissue is most commonly affected in individuals due to trauma, progression, detrimental lifestyle habits such as smoking and chronic alcoholism, or even systemic infections, diseases, or invasive cancers.
What Are the Types of Developmental Disturbances Affecting Oral Lymphoid Tissues?
The common lymphoid tissue disorders or disturbances affecting the oral cavity or head and neck region are listed below:
1. Reactive Lymphoid Hyperplasia of the Oral Cavity or Reactive Lymphoid Aggregates: These aggregates can occur anywhere in the oral cavity, but they are subdivided based on their location.
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This condition, also known as reactive lymphoid hyperplasia, commonly affects the lingual tonsils, where a large oral lymphoid aggregate is present. The lingual tonsil is situated in the posterior region of the tongue. Inflammation or enlargement can be observed unilaterally or bilaterally and is often mistaken for an early stage of cancer or carcinoma if incorrectly diagnosed.
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Reactive hyperplasia affecting the lymphoid tissue can similarly involve other regions, such as the buccal mucosa in the oral cavity. These lesions may be clinically observed as firm submucosal nodular masses that are visible to the oral surgeon and may be tender to the touch.
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There would also be polyps of hyperplastic lymphoid tissues known as ‘hyperplastic lymphoid polyps’ that can occur anywhere in the oral cavity, such as the gingiva, buccal mucosa, floor of the mouth, or tongue.
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Early microscopy and diagnosis by the oral pathologist are crucial to differentiate these lymphoid tissue aggregates from early cancers of the oral cavity. Additionally, these inflamed lymphoid tissue sites could potentially be regions or sites where malignant lymphoma or a group of lymphoma cancer lesions may develop if these initial lesions are left untreated. Conservative or systemic treatment would be required for extra-nodal involvements.
2. Lymphoid Hamartoma: These lesions of lymphoid tissue in the oral cavity are known by various clinical names in the medical literature. They are commonly referred to as angiofollicular lymph node hyperplasia or Castleman's disease. These growths occur in lymph nodes throughout the body and can also manifest in the oral cavity. In systemic lymph and plasma diseases, such lesions are common and non-cancerous. However, they may be associated with clinical symptoms such as fever, weight loss, rashes, early destruction of erythrocytes (red blood cells), hemolytic anemias, or abnormal immune blood factors/hypergammaglobulinemia. Individuals suffering from Castleman's disease or lymphoid hamartomas commonly exhibit an enlarged liver and spleen; the exact cause of this disease is unknown in the medical literature. Conservative and systemic interdisciplinary treatment is needed.
3. Angiolymphoid Hyperplasia With Eosinophilia (ALHE): ALHE is an idiopathic yet uncommon condition that presents as grouped lesions or plaques affecting the head and neck region. These are benign tumors or neoplasms that occur due to unusual reactions to various stimuli, such as trauma to the head and neck region. ALHE may be uncommon, but this condition is not rare, considering several cases have been reported in medical and dental literature regarding its incidence. These lesions in the head and neck region may appear as dome-shaped superficial papules or nodules and may also occur near the ear or scalp of the individual. These benign lymph tumors may recur even after treatment by the maxillofacial surgeon. Treatment usually involves the administration of intralesional corticosteroids and irradiation. Surgical removal of the lesions can be performed in the head and neck region for these tumors when they are large-sized by an oral and maxillofacial surgeon.
4. Lymphoepithelial Cyst: This is one of the major developmental disturbances affecting oral lymphoid tissues. It begins as a benign lymphoid aggregation in the oral or pharyngeal mucosa. This cyst was first described in medical literature by Parmentier in 1857 as a hydatid cyst. They commonly affect the head and neck region and other organs like the pancreas and testes in males. There are different versions of the lymphoepithelial cyst in the neck, such as the branchial cleft cyst, and in the salivary glands as a parotid cyst (commonly found as a clinical cyst in AIDS patients). These cystic lesions present as movable masses and are usually painless in the head and neck region or in the oropharyngeal mucosa, exhibiting a nodular appearance or a typical yellow-white discoloration. It is common in the third decade of life, especially when it occurs in the oral cavity. Various sites where it can occur include the floor of the mouth, the lateral or central tongue surface, and the pharyngeal tonsil mucosa, among others.
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Occasionally, patients might complain that this cyst emits a foul-smelling material consisting of keratin in the mouth or oral cavity when the superficial cysts rupture. Although these lesions are painless, cysts often cause oral discomfort when they occur in this region or in the head and neck region. However, there is no scope for these lesions to turn malignant or cancerous.
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If the patient ignores the cysts or is left untreated, there is a risk of developing extranodal lymphoma, which means that the lymphatic disease can spread to extraoral sites from the untreated infection. Hence, maxillofacial surgeons would recommend that this lymphoepithelial cyst be ideally treated using conservative methods like surgical excision. If the site is constantly traumatized again after surgery, then recurrence would be possible.
Conclusion:
Though none of the developmental disturbances affecting oral or head and neck lymphoid tissue are cancerous or malignant, the maxillofacial surgeon needs to diagnose the lesions and treat them conservatively in a timely manner. This is done to prevent these lesions' progression into conditions that can potentially transform into life-threatening infections or cancers.
