Dermatology Online Journal

Case report: Mucosal melanoma of the lip and the cheek
A Disky, D Campos, H Benchikhi
Dermatology Online Journal 14 (8): 20

Dermatology Department, UHC Ibn Rochd, Casablanca, Morocco. diskyasmaa@yahoo.fr

---

Abstract

Mucosal malignant melanoma arising from the mucosa of the head and neck region is a rare entity. We report one case of mucosal melanoma of the lower lip and the internal face of the cheek. Lymph nodes were not detected in the submandibular or cervical region. The patient had a large exerese of the lower lip and internal area of right cheek and an unilateral neck lymph node dissection. Histopathology showed superficial extended melanoma type SSM, index Clark III, fair metotic index and breslow index 1.5 mm. Lymph node metastasis was not found. Reconstruction was done after 15 days. Complementary investigation showed metastatic lesions but without confirmation. The interest of our observation relies on the rarity of the mucosal melanoma of the lip and the difficulty of the treatment. This patient represents the first case of mucosal melanoma in our series. The particularity is the presence of 3 lesions. In our case, unilateral neck lymph node dissection was indicated in reason of gravity of mucosal melanoma and because sentinel lymph node is impossible on the neck.

---

Introduction

Mucosal malignant melanoma arising from the mucosa of the head and neck region is a rare entity, accounting for approximately 0.2 percent of all melanomas. Most of these lesions (80%) have occurred on the maxillary anterior gingival area. They can also be seen in buccal mucosa, mandibular gingiva, tongue, base of oral cavity and the lips in a decreasing frequency [1, 2, 3]. We report 1 case of mucosal melanoma of the lower lip and the internal face of the cheek.

Case report

A 46-year-old man presented with pigmented lesions of the internal face of the lower lip and the cheek. He was referred to a dermatologist who biopsied the lesions; the histologic result was "mucosal malignant melanoma." For further investigation and treatment, the patient was referred to our hospital in April 2007.

The patient's history included alcohol consumption for 5 years and had smoked 1 to 1.5 packages of cigarettes per day for 10 years. He had 3 asymptomatic progressively enlarging pigmented macules. They were located on the mucosal face of the lower lip and the right cheek. According to the patient, the lesions were roughly of 4 months duration and did not significantly change in color and in size over time, but after another month the patient had noticed the appearance of a nodule in median lesion of lower lip.

Figure 1	Figure 2
Figures 1 & 2. Mucosal melanoma: pigmented lesions of the internal face of the lower lip and the cheek

On clinical examination, the lesions appeared as irregularly pigmented tan to brown-black macules with regular borders, approximately 10-15 mm in diameter with a nodule of 0.5 cm (Figs. 1 & 2). Lymph nodes were not detected in the submandibular or cervical region.

Figure 3
Figure 3. Superficial extended melanoma (HE, x40)

In searching for distant metastasis, 2 nodules were detected in the last handle of the small intestine and the spleen (2 cm - 4 cm) on thoraco-abdominal computerized tomography. The complementary echographic exploration and the enteroscanner confirmed the nodular lesion of the spleen but not the one of the small intestine.

Figure 4	Figure 5
Figures 4 & 5. Tumor cells with abundant pigment (HE, x100, x400)

The patient had a large exerese of the lower lip and internal area of right cheek and an unilateral neck lymph node dissection. Histopathology showed superficial extented melanoma type SSM, index Clark III, fair metotic index and breslow index 1.5 mm (Figs. 3, 4, & 5). Lateral and internal limits were normals. Lymph node metastasis was not found. Reconstruction was done after 15 days from the upper lip with a good result (Figs. 6 & 7). Fifteen days later, the patient had a spleenectomy. Histology showed just hematoma. The patient did not receive any other complementary treatment with a follow-up 4 months later.

Figure 6	Figure 7
Figures 6 & 7. Patient after reconstruction

Discussion

The interest of our observation relies on the rarity of the mucosal melanoma of the lip and the difficulty of the treatment. This patient represents the first case of mucosal melanoma in our series. The particularity is the presence of 3 lesions. There is a possibility of melanoma occurring in the normal mucosa of the upper aerodigestive tract because melanocytes exist in these localizations [1]. The etiological basis for the origin of mucosal melanomas is less well understood than it is for cutaneous melanomas. Certain etiological factors such as exposure to sunlight do not apply to mucosal melanoma [4].

Melanoma of the oral mucosa is less common than cutaneous melanoma. The neoplasm usually appears in persons after the age of 50 years [1, 2]. Many investigators report a male to female ratio of 2:1 as our case [1-5]. Mucosal malignant melanoma are more aggressive and behave differently than cutaneous melanomas [1, 6]. Pathologic description and leveling system cannot be applied for mucosal melanomas. The critical factor that determines the prognosis of melanoma of skin is vertical invasion depth; however, the Breslow classification is not a valuable prognostic determinant for oral cavity tumors. As there are no muscle bundles and a true dermis in the oral cavity, we cannot apply Clark classification for these tumors [1, 6, 7]. Although, our pathologist gave Clark and Breslew classification.

Oral melanoma has a predilection for metastasis to the lungs, liver, brain and bones [1]. In our case, complementary investigation showed metastatic lesions but not confirmed at surgery. There is general agreement that the surgery is the treatment of choice for oral malignant melanoma.

Most authors advocate wide local excision [1, 2]. Surgery that achieves clear margins without compromising cosmetic and oral function has usually been favored of the lesions with or without lymph node dissection but frequently, surgical acte is large and complicated as shown here [1, 4]. In our case, unilateral neck lymph node dissection was indicated in reason of gravity of mucosal melanoma and because sentinel lymph node is impossible on the neck. Systemic chemotherapy is used in patients with advanced stage III (unresectable regional metastases) or stage IV (distant metastases) [1, 4].

Conclusion

Mucosal malignant melanoma are more aggressive than cutaneous melanomas. On the other hand, complex anatomy of this area makes complete surgical excision difficult. Thus, early diagnosis and treatment are important [1].

References

1. Ulusal B.G., Karatas O., Yildiz AC., Öztan Y. Primary malignant melanoma of the maxillary gingival. Dermatol Surg 2003 ; 29 : 304-7. PubMed.

2. Mirowski GW., Waibel JS. Pigmented lesions of the oral cavity. Dent Clin North Am, 2005; 49 (1) : 185-201. PubMed.

3. Massi D, Nardini P, De Giorgi V, Carli P. Simultaneous occurence of multiple melanoma in situ on sundamaged skin (lentigo maligna), solar lentigo and labial melanosis : the value of dermoscopy in diagnosis. J Europ Acad Dermatol Venereo. 1999 ; 13 : 193-7. PubMed.

4. Nandapalan V, Roland NJ, Helliwell TR, Willimas EMI, Hamilton JW, Jones AS. Mucosal melanoma of the head and neck. Clin Otolaryngol 1998 ; 107 (7) : 626-30. PubMed.

5. Veness M. Lip cancer : important management issues. Case report. Australasian Journal of Dermatology 2001, 42 : 30-2. PubMed.

6. Martin JM. Porceddu S, Weih L, Corry J, Peters LJ. Outcomes in sinonasal mucosal melanoma. Anz J Surg 2004, 74 :838-42. PubMed.

7. Bongiorno MR, Arico M. Primary malignant melanoma of the oral cavity : case report. Int J Dermatol 2002, 41 : 178-81. PubMed.

© 2008 Dermatology Online Journal