原文題目

口腔病理科 On-Line KMU Student Bulletin

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原文題目(出處)： Extensive epidermoid cyst and breathing difficulty. Case Rep Dent 2015, Article ID 826389

原文作者姓名： Soares CD, Gurge AC, Francisco Souza Júnior de Assis de, Samila de Oliveira N, de Carvalho MGF, Oliveira HG 通訊作者學校： Department of Oral Diagnosis, Piracicaba Dental School,

Universidade Estadual de Campinas, Brazil

報告者姓名(組別)： 許立言 Intern C 組

報告日期： 104/10/06

Introduction

1. Epidermoid cysts (EC) are common cystic lesions in skin, testicles, and ovaries.

They comprise less than 0.01% of all oral cavity cysts and their occurrence in the floor of the mouth with respiratory complications has not been reported.

2. EC are bounded by fibrous capsule and are composed of an epithelium which is flattened and contains a granular layer of keratohyalin granules. EC does not have hair follicles, sebaceous glands, and apocrine sweat glands (skin appendages) in capsule to differentiate between dermoid cysts.

3. The epithelial cells malignant transformation of these cysts has been reported but is rare.

Case Report

1. A 45-year-old male patient presents with extensive mass in the buccal floor, with limitation in mouth opening and speech associated with dysphagia and dyspnea.

2. The clinical examination revealed an expansive mass, asymptomatic, exophytic, and no history of associated trauma, and fluctuated upon palpation (Figure 1). The lesion surface had normal-appearing overlying mucosa.The clinical diagnosis was ranula, dermoid cyst, or epidermoid cyst.

(Figure 1)

3. A CT scan was performed showing the dimensions of the lesion, as well as confirming the hypothetical diagnosis of the internal liquid contents. Aspiration puncture demonstrated content material friable and white. Surgical planning included complete lesion excision. After this the specimens were removed and were sent for anatomical pathologic evaluation. (Figure 2)

(Figure 2)

4. It was measured to be 5.0 x 3.0x 0.2 cm and it had brown pigmentation with a few whitish areas. Microscopic examination revealed a cystic cavity with a capsule composed of dense fibrous connective tissue, lined by stratified squamous epithelium resembling epidermis (Figure 4(a)). There were no skin appendages in the capsule. The lesion contents were represented by concentric blades of orthokeratin. A breach on the cyst wall with chronic granulomatous inflammation

口腔病理科 On-Line KMU Student Bulletin

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and multinucleated giant cells was also observed (Figure 4(b)), including keratin, being the final diagnosis of a ruptured epidermoid cyst, with granuloma to the foreign body (keratin).

Discussion

1. Etiology: (1) The epidermoid cysts (EC) have uncertain etiology and may be formed from reactivation of epithelial remnants entrapped during midline closure of the bilateral first and second branchial arches. (2) Accidental introduction of epithelium in the subcutaneous tissues or in the submucosa after extraction of a third molar.

2. Differential diagnosis: infectious lesions of the salivary glands, ranula, dermoid cyst, lipoma, lingual thyroid, and thyroglossal duct cyst. In the present case the hypothesis of diagnosis was ranula, dermoid cyst, and EC.

3. CT permits visualizationof the differences in densities of hard and soft tissues thus optimizing the diagnosis and it guides the surgeon for a more efficient treatment plan and enables visualizing the relationship of the lesion with muscles, salivary glands, and other tissues.

4. Epidermoid cysts are benign lesions; however, they may have large dimensions and cause physiological complications including swallowing and breathing difficulty. The computed tomography is a method efficient for assessing the relationship with the adjacent anatomical structures and planning of surgical approach.

題號 題目

1

(A) Frequently in children and young adults (B) Usually cross the midline

(C) May rupture and release its mucin (D) Appears at the floor of the mouth

答案(B) 出處：Oral and maxillofacial pathology, third edition, p.457

題號 題目

2 Which of the following is not a histological feature of epidermoid cyst?

(A) Stratified squamous epithelium (B) Cavity filled with orthokeratin

(C) Sebaceous glands, hair follicle, and apocrine sweat glands (D) Cyst wall, lining epithelium, and lumen

答案(C) 出處：Oral and maxillofacial pathology, third edition, p.32