原文題目(出處)： Ectopic oral tonsillar tissue: A case series with bilateral and solitary presentations and a review of the literature. Case Rep Dent Volume 2014, Article ID 518917.
原文作者姓名： Masashi Kimura,Toru Nagao,Terumi Saito,Saman Warnakulasuriya,Hiroyuki Ohto,Akihito Takahashi,Kanji Komaki,and Yoshiyuki Naganawa
通訊作者學校： Department of Dentistry Oral and Maxillofacial Surgery, Ogaki Municipal Hospital, Minaminokawa, Ogaki, Gifu Japan
報告者姓名(組別): 翁依岑（Intern G 組）
報告日期： 104/02/09
內文：
Introduction
The tonsils form part of a circular band of adenoid tissue known as Waldeyer’s ring, which guard the opening of the digestive and respiratory tracts.
This circular band is comprised of four major tonsil groups: the palatine, lingual, pharyngeal, and tubal tonsils.
An ectopic tonsil is tonsillar tissue that develops in areas outside of these regions.
The existence of ectopic oral tonsils was described by Knapp in 1970.
It was shown that such structures, resembling pharyngeal and other tonsils, can be found within the oral cavity.
Ectopic tonsils have been reported in different anatomic locations of the oral cavity, for example,on the floor
of the mouth, ventral surface of the tongue, and soft palate, and in other parts of the aerodigestive tracts, for example, larynx, hypopharynx, nasal septum, or in the orbit.
Here we report a rare case of bilateral symmetric ectopic oral tonsillar tissue observed on the ventral surface of the tongue and two other solitary cases arising from floor of the mouth along with a review of the literature.
Case presentations:
Case 1
A 53-year-old Japanese male, referred by his general dental practitioner, presented with small, bilaterally symmetric masses on the ventral surface of the tongue, noticed during a routine dental examination 2 months ago.
The areas affected were painless and remained unchanged in size over the previous 2 months.
Intraoral examination revealed hard masses of 8 mm diameter (right) and 6 mm diameter (left) on the ventral surface of the tongue.
The surface covering of these masses was slightly red and was hard on palpation.
Clinically, a small pit was evidentat the tip of both masses; a provisional diagnosis of bilateral benign tumors of salivary origin was made.
An excision biopsy of the mass on the right side was subsequently performed under local anesthesia.
Histopathological findings showed a germinal center, lymphoid tissue, and lymphoepithelial symbiosis in the crypt.
Case 2
A 63-year-old Japanese female presented at our hospital with a small swelling on the left side of the floor of the mouth.
She first noticed this lump 10 days
previously. The affected area was painless and its size remained unchanged.
Intraoral examination revealed a well-circumscribed mass (5 mm diameter)
The mass was slightly red and hard on palpation and was clinically diagnosed as a benign salivary tumor of the floor of the mouth.
It was resected under local anesthesia and at excision was found to be encapsulated and appeared fairly close to the sublingual salivary gland.
Histopathology revealed characteristic features of a tonsil with a germinal center, a mass of lymphoid tissue, and a crypt with lymphoepithelial symbiosis. These findings were suggestive of ectopic tonsillar tissue.
Case 3
A 38-year-old Japanese female visited our clinic complaining of a small painless lump on the right side of the floor of the mouth.
She first noticed this lesion 2 days ago.
Intraoral examination revealed a well-
circumscribed mass (6 mm diameter) covered by intact normal-appearing mucosa .
The mass wassoft on palpation and was clinically diagnosed as a mucocele of the floor of the mouth.
It was resected under local anesthesia and at excision it was completely detached from the sublingual salivary gland and Wharton’s duct by its own capsule.
Pathological characteristics were similar to the earlier described cases.
Discussion
Ectopic tonsils are comprised of a single or branched crypts containing lymphoid follicles lined with stratified squamous epithelium.
In Table 1, we present single cases and case series of ectopic tonsils.
A literature search was conducted in August 2014 using
the electronic databases PubMed and Scopus and hand-searching using the search term of ectopic tonsil.
The search was restricted to
published articles containing clinicopathological features.
As a result, the most frequently affected area is the floor of the mouth (59%
of cases), followed by the soft palate (24.6%) and ventral surface of the tongue (9.8%).
In the clinical findings, the size of the lesions ranged from 3 to 28mm with rounded shape, and the surface covering of the lesions was occasionally and slightly red.
It may be misdiagnosed as tumors that arise from the sublingual gland.
According to Patel et al. inflamed ectopic tonsils may swell and become tender, thus requiring resection.
Usually, however, ectopic oral tonsils remain asymptomatic and can be left untreated, but surgical exploration is indicated to establish a tissue diagnosis.
In Case 1, excisional biopsy of one mass led to a histopathological diagnosis of ectopic tonsillar tissue. Thus, the need for surgical resection of the contralateral lesion was avoided.
The pathogenesis of ectopic tonsils in this region remains unclear.
Lymphoid tissue is also found in fetal salivary glands, and occasionally remnants of lymphoid tissue are found in adult salivary glands.
The masses in Cases 2 and 3 appeared close to the sublingual gland but were completely separated from the salivary tissues, whereas the masses in Case 1 were placed distant from the salivary tissues, and thus the origins of these masses remained obscure.
It is reported that ectopic tonsillar tissue in the nasal septum may result from persistent infection.
Further cadaveric study is required to clarify the presence of ectopic tonsillar tissue on these anatomical sites, particularly with regard to its developmental mechanisms, and to assess its prevalence and to study the clinical significance of the immune system and its response.
Ectopic tonsils appear to occur more frequently than are generally recognized, probably because they are usually asymptomatic and are thus easily overlooked.
題號 題目
1 Where is the most frequently affected area of ectopic tonsils?
(A) floor of the mouth
(B) soft palate
(C) ventral surface of the tongue
(D) nasal septum
答 案 (A)
出處：Oral and maxillofacial pathology third edition P185~186
題號 題目
2 Which is not the four major tonsil groups in the circular band?
(A) palatine tonsils
(B) lingual tonsils
(C) Pharyngeal tonsils
(D) laryngeal tonsils
答 案 (D)
出處：Oral and maxillofacial pathology third edition P185~186
