原文題目(出處)： Primary oral malignant melanoma: Two case reports and review of literature. Case Rep Dent 2012, Article ID 975358.
原文作者姓名： Neeraj Sharma
通訊作者學校： Department of Oral Medicine and Radiology, Panjab University, Chandigarh 160014, India
報告者姓名(組別)： 劉鏗全 (Intern F 組)
報告日期： 2013/2/4
內文：
I. Abstract
Primary malignant melanoma of the oral cavity is a rare neoplasm. The tumors tend to metastasize or locally invade tissue more readily than other malignant tumors in the oral region.
The survival rate: Cutaneous melanomas > mucosal melanomas
Gingival melanoma > palatal melanoma in 5y F/U Tumor size and metastases are related to the prognosis of the disease.
II. Introduction
1. Malignant melanoma is a potentially aggressive tumor of melanocytic origin.
2. 1~8% of all melanomas arise in the oral mucosa 3. predilection of oral site : palate & maxillary gingival 4. Predilection age : 20~80y/o
5. Predilection country : Africa & Japan > Western countries
6. Etiopathogenesis and function of mucosal melanomas is poorly understand;
however, it is well documented that the melanocytes migrate to both endodermally derived and ectodermally derived mucosa
III. Case Report 1. Case 1 :
a. General data : A dark 60y/o male
b. C.C. : Recurrent growth in the lower front region since 20 days
c. PDH : Excision of similar growth about eight months back (Tx details &
histopathology reports were not available) d. PMH : Non-contributory
e. Oral habit : Smoking (+), Alcohol (+)
f. Extra-oral examination : lymph node enlargement (-)
g. Intra-oral examination : An exophytic growth of 2.5X4 cm on lingual aspect of tooth 35 to tooth 42. The growth was pedunculated, arising from the marginal and attached gingiva of mandibular left incisors and canine. It is a well defined, firm, nontender and covered with white pseudomembrane, Removal of the pseudomembrane revealed blackish underlying surface. Mandibular labial/buccal marginal and attached gingiva was black, multiple satellite lesions could be seen on the floor of the mouth.
h. X-ray findings:
> Pano: horizontal bone loss and loss of lamina dura in relation to mandibular incisors, generalized rarefaction in the adjoining bone
> CT: 2.3X4.4 cm enhancing lesion extending from tooth 35 to 42. Erosion of anterior cortex of the L’t body of mandible to the symphyseal region. Enlarged enhancing bilateral level I and II lymph nodes were seen.
i. Diagnosis: malignant melanoma 2. Case 2
a. General data: 50y/o male
b. C.C.: pain in the tooth 16 & a blackish growth on the R’t side of hard palate since 12days
c. PMH: medications taking and other illness (-) d. Oral habit: N/P
e. Extra-oral examination: Bil. Submandibular lymph nodes enlargement, oval in shape, mobile, and nontender.
f. Intra-oral examination: a black exophytic growth on R’t hard palate, extended onto the buccal gingival between tooth 16 & 17, soft in consistency, nontender. Small satellite lesions were on the palate surrounding the lesion.
g. X-ray findings:
> Pano: tooth 16 & 17 carie with interdental bone destruction. The continuity of the floor of the maxillary sinus was disrupted in the tooth 16 region. The PDL in tooth 15, 16, 17, 18 was widened
> CT: ill-defined enhancing soft tissue mass on right side of hard palate, extending posteriorly up to the soft palate. No erosion or sclerosis of bone due to the soft tissue mass. Bilaterally enlarged level I, II, V lymph nodes were seen.
Two cases treatment: Excision with radical neck dissection and post-OP radiotherapy Histopathological studies: numerous atypical melanocytes within the epithelium
and also invasion into the connective tissue .These cells were epitheloid to spindle in shape, with vesicular 囊狀, hyperchromatic 多色差 nuclei, and prominent nucleoli. Few mitotic 有絲分裂 figures were also seen. Confirmed the diagnosis of malignant melanoma
IV Discussion
1. Oral melanoma classification : > Pigmented nodular > Nonpigmented nodular > Pigmented macular > Pigmented mixed > Nonpigmented mixed
2. Initial S/S of OM is often a pigmented growth or swelling, may be smooth suface, with an intact or ulcerated overlying mucosa.
3. Satellite foci may surround the primary tumor
4. Color: uniformly brown, black or may show variation of color (black, brown, grey, purple, red shades, depigmentations)
5. Other S/S: bleeding, ill-fitting dentures, pain, increased mobility of teeth, delayed healing of extraction sockets, regional lymphadenopathy may present a poor prognosis
6. Biopsy is mandatory when oral pigmentation cannot be confidently diagnosed as benign.
> Excisional biopsy: 1~2 mm margin for small lesion > Incisional biopsy: thickest or the most suspicious part
7. Fine needle aspiration or exfoliative cytology is contra-indication
8. It has been suggested that cutting into a malignant neoplasm during an incisional biopsy or other invasive procedure could result in accidental dissemination of malignant cells within the adjacent tissues (seeding) or even in the blood or lymphatic stream, with the subsequent risk of local recurrence, or regional or distant metastasis 9. The most common sites of metastasis are lung, bone, brain, and liver, with widespread involvement occurring in advanced disease
10. Malignant cells of OM show a wide range of shapes, including spindle, plasmocytoid, clear cell, and epithelioid ones
11. These malignant cells possess considerable pleomorphism with large, irregular hyperchromatic nuclei, and prominent nucleoli, and have readily detectable mitotic activity.
12. OMs can be histologically subclassified into
> in situ melanoma, which is limited to the epithelium and the epithelial-connective tissue interface
> melanomas with an invasive pattern, in which the neoplasm extends into the connective tissue
> melanomas with a combined pattern of invasive melanoma with in situ component
13. TNM clinical staging:
Stage1 Primary tumour present only (Tany N0M0) Level I Pure in situ melanoma without evidence
of invasion or in situ melanoma with “microinvasion,”
Level II Invasion up to the lamina propria
Level III Deep skeletal tissue invasion into skeletal muscle, bone, or cartilage
Stage II Tumour metastatic to regional lymph nodes (Tany N1M0)
Stage III Tumour metastatic to distant sites (Tany Nany M1) 14. Treatment of oral melanoma is still controversial.
15. Excision: intra-oral approach, involving at least 1.5mm healthy tissue 16. P’t with oral melanoma present lymph node metastasis in 25% case
> Neck dissection should be reserved for cases with preoperatively confirmed lymph node
17. Surgery could be combined with radiotherapy, chemotherapy, or immunotherapy even though the effectiveness of such therapies is mostly unknown.
18. Post-OP radiotherapy is generally recommended if poor prognostic pathologic features are present, even though OMs are regarded as poorly radiosensitive
19. Post-OP chemotherapy: Dacarbazine, platinum analogs, nitrosoureas, microtubular toxins, dimethyl triazeno imidazole carboxamide (DTIC), nimustine hydrochloride, or vincristine
20. The prognosis of OM is poor. A tumor thickness greater than 5 mm, presence of vascular invasion, necrosis, polymorphous tumor cell morphology and the inability to properly resect the lesions with negative margins have been associated with poor survival in patients with primary
V. Conclusion
Primary oral mucosal melanomas are exceedingly rare and biologically aggressive malignancies, OMs clinically mimic many other pigmented lesions of the oral cavity. Practitioners who treat oral lesions should include malignant melanoma in the differential diagnosis of pigmented lesions because early diagnosis and intervention result in better prognosis.
題號 題目
1 Melanoma is rarely occur in oral cavity, if occur, which is the predilection site?
(A) Palate and upper gingival
(B) Tongue
(C) Buccal mucosa
(D) Retromolar region
答案(A) 出處：Oral and Maxillofacial Pathology 3rd edition,p435
題號 題目
2 Which oral melanoma occurs most commonly?
(A) Nodular melanoma 結節狀黑色素瘤
(B) Acral lentiginous melanoma 肢端雀斑黑色素瘤 (C) Superficial spreading melanoma 表面擴散黑色素瘤
(D) Amelanotic melanoma 無色性黑色素瘤
答案( B) 出處：Oral and Maxillofacial Pathology 3rd edition,p435
