原文題目(出處)： Central mucoepidermoid carcinoma: Report of a case with 11 years’evolution and peculiar macroscopical and clinical characteristics. Med Oral Patol Oral Cir Bucal 2009;14:E283-6.
原文作者姓名： Renata Tucci , Luciana-Fasanella Matizonkas-Antonio , Artur-Aburad de Carvalhosa , Paulo-Henrique-de Sousa Castro , Fabio-Daumas Nunes , Décio-dos Santos Pinto Jr 通訊作者學校： Institute of Health Research, Av. Indianópolis, 153
São Paulo - SP – Brazil.
報告者姓名(組別)： 陳覺斌 (Intern F 組) 報告日期： 100/01/11
內文：
Abstract
1. Central mucoepidermoid carcinomas (CMC) are uncommon tumours, comprising 2-3% of all mucoepidermoid carcinomas.
2. They have been reported in patients of all ages, ranging from 1 to 78-years, with the overwhelming majority occurring in the 4th and 5th decades of life.
3. They are histologically low-grade cancers,usually affecting the mandible as
uniocular or multiocular radiographic lesions.
4. The authors report a case of CMC of the mandible with a long evolution, and peculiar clinical and macroscopical features related with the long term evolution of the disease.
a. A 53-year-old male patient had expansion of buccal and lingual cortices of the anterior region of the mandible, covered by ulcerated mucosa, with 11 years evolution.
b. An incisional biopsy was performed, and the histopathological findings confirm low-grade mucoepidermoid carcinoma.
c. The patient was treated with a mandibulectomy, followed by
supraomohyoid neck dissection.
d. There was no evidence of local recurrence, regional or distant metastasis revealed; and the patient was alive and without disease after a followup interval of 36 months.
Introduction
1. Some 90% of oral cancers consist of squamous cell carcinomas that arise from the oral mucosa.
2. The remaining 10% of malignancies consist of a. malignant melanomas,
b. carcinomas of the intraoral salivary glands, c. sarcomas of the soft tissues and the bones, d. malignant odontogenic tumors,
e. non-Hodgkin’s lymphomas
f. metastases from primary tumors located elsewhere in the body.
3. Salivary gland tumours are an important part of the Oral and Maxillofacial Pathology and represent 3-5% of all head and neck neoplasms.
4. Central mucoepidermoid carcinomas (CMC) are extremely rare, comprising
2-3% of all mucoepidermoid carcinomas.
5. We found reports of about 120 cases of central mucoepidermoid carcinomas.
The origin of the CMC is controversial and several possibilities have been considered, including:
a. metaplasia of odontogenic cysts epithelium,
b. entrapment of salivary tissues from the submandibular, sublingual or minor salivary glands, during embryonic development,
c. entrapment of minor salivary glands from the retromolar area, d. maxillary sinus epithelium,
e. iatrogenic entrapment of minor salivary glands (e.g. chronic
osteomielitis and sinusitis) and odontogenic remnants of the dental lamina.
Case Report
1. A 53-year-old man was referred to the Oral Medicine Service at the Cancer Hospital, Cuiabá, Mato Grosso,Brazil, for the diagnosis of mandibular lesion with 11 years evolution (Fig.1A).
2. Clinical examination of the oral cavity revealed expansion of buccal and lingual cortices of the anterior region of the mandible, covered by ulcerated
mucosa (Fig.1B).
3. Cervical lymphadenopathy was absent.
4. A computed tomography showed lobulated osteolytic lesion inside the mandibular body with inexate limits and cortical rupture (Fig.1C and 1D).
5. An incisional biopsy of the intraosseous lesion was performed.
6. Histological examination of the specimen revealed a neoplasm composed predominantly of cystic spaces, containing myxoid material produced by clear cells, and nests of epidermoid cells
(Fig.2).
7. Gross examination of the ressected specimen revealed brownish tumoral mass involving all the jaw body, buccal and lingual cortical, from left to right molars.
8. After cutting the surface, pseudo-cystic cavities showing green mucous
secretion were observed (Fig.3A). 20 ml of mucous secretion were removed into the cavities (Fig.3B). The histopathological characteristics of
pseudo-cystic cavity showing mucous secretion are observed in (Fig.3C).
9. A histopathological analysis the surgical specimen reconfirmed the diagnosis of the low-grade mucoepidermoid carcinoma.
10. The patient is on regular follow-up and is disease free after 3 years.
Discussion
1. Primary central salivary gland carcinomas of the mandible are uncommon neoplasms.
2. Mucoepidermoid carcinoma generally affects the salivary glands and only rarely is located in the jaws.
3. CMC affects females twice more frequently than males and involves the
mandible twice more often than maxilla.
4. The most common site of occurrence is the premolar-molar-angle region of
mandible.
5. The criteria for diagnosing CMCs include:
a. Presence of a radiographic distinct osteolytic lesion b. Positive mucicarmine staining
c. absence of rupture of one or more cortical plates
d. clinical and histological exclusion of a metastasis or an odontogenic lesion
e. exclusion of the origin from a soft tissue salivary gland f. histologic confirmation .
6. Our case showed rupture of cortical plate, but it has been shown in the literature that intact cortical plates should not be an essential feature for diagnosis of CMCs
7. Brookstone et al. in 1992 proposed a staging system based on the condition of the overlying bone.
a. Staged I：Lesions with intact cortical plates with no evidence of bone expansion
b. Staged II：tumors with intact plates but intraosseous expansion
c. Staged III：lesions associated with cortical perforation or nodal disease d. Our case is in staged III, because showed rupture of cortical plate.
8. Most of the reported, CMC are histologically low-grade tumours and usually carry a favorable prognosis .
9. As a rule, even being low-grade tumours, CMC should be managed by wide
local resection. Our case shows that, although the CMC is considered a low
malignant potential carcinoma, in long-term evolution, it can be locallyaggressive and requires wide en bloc resection.
10. In these cases, bloc resection and effective followup are necessary for the success of the treatment.
題號 題目
1 何者是 central mucoepidermoid carcinoma 好發部位?
(A) 上顎前牙區 (B) 上顎後牙區 (C) 下顎前牙區 (D) 下顎後牙區 答案
(D )
出處： Oral & Maxillofacial Pathology, Second Edition. p.422
題號 題目
2 關於 central mucoepidermoid carcinoma (CMC) ,下列敘述何者為非?
(A) 好發於 middle-aged (B) 好發於下顎
(C) 好發於男性 (D) 好發於後牙 答案
(C)
出處： Oral & Maxillofacial Pathology, Second Edition. p.422
