Clinical Findings

It was a 55-year-old taxi driver with an antecedent of chronic solar exposure since childhood, admitted in our department for the management of a purple tumor on the right earlobe evolving for 6 months after handling a hair, painless and non-pruriginous.

The dermatological examination showed the presence of a 4 cm purple tumor located at the right earlobe with infiltrated basis, and a small ulceration in the center, the dermoscopy objectified the presence of purple laguna separate by fibrous septas with an ulceration and a rainbow pattern, the diagnosis of angiokeratoma, epidermised botriomyoma or kaposi disease was evoked, other diagnosis was cutaneous metastasis of a renal or hepatic tumor or a melanoma. Histology with immuno histochemistry confirmed a nodular-type melanoma, an extension assessment was performed revealing pulmonary and hepatic metastasis, oncological management was preconized.

Discussion

It has been estimated that melanoma of the ear accounts 7-13% of all cutaneous melanomas of the head and neck [1,2]. Presentation can range from subtle macules and patches to ulcerated nodules.

At the level of the ear, melanomas are mainly located in the pavilion level and are exceptional at the level of the EAC. Pavilion melanomas preferentially occur in men (60 to 75%), while at the level of the head and neck, they are significantly frequent in women (54%).

The age of onset is lower than for carcinomas (56 years) and the young adult or even the child can be affected [3]. At the pavilion level, the localization of the lesion is most often the helix (60%), then the lobule, the tragus and the pre-tragic region, the conch and the anthelix.

Dermoscopy is a valuable aid to discuss the diagnosis of nodular melanoma in this atypical localization. The rainbow pattern (RP) or the structureless polychromatic zone (H. Kittler) is currently considered the specific dermoscopic pattern of Kaposi sarcoma [4]. However this fact has been brought into question by the great correspondence of Vazquez-Lopez et al. who presented four observations of melanoma, stasis dermatitis, lichen planus and haemosiderotic dermato-fibroma [5].

Furthermore, there is no agreement on the biological behavior of melanoma of this region: some authors claim a better prognosis and propose less invasive treatments [6], while others consider external ear melanoma more aggressive. As a consequence, its treatment is not standardized, which often differs from standard treatment for melanomas of other regions [7]. In our case, despite the conservation of the general condition, melanoma of the earlobe was aggressive with the rapid onset of metastasis.

References

1. Byers RM, Smith JL, Russell N, Rosenberg V. Malignant melanoma of the external ear. Review of 102 cases. Am J Surg. 1980; 140(4): 518-521.   
2. Urist MM, Balch CM, Soong SJ, et al. Head and neck melanoma in 534 clinical Stage I patients. A prognostic factors analysis and results of surgical treatment. Ann Surg. 1984; 200(6): 769-775.   
3. Staub G, Revol M, May P, Bayol JC, Verola O, Servant JM. [Excision skin margin and recurrence rate of skin cancer: a prospective study of 844 cases]. Ann Chir Plast Esthet. 2008; 53(5): 389-398. doi: 10.1016/j.anplas.2007.07.015   
4. Cheng ST, Ke CL, Lee CH, Wu CS, Chen GS, Hu SC. Rainbow pattern in Kaposiʼs sarcoma under polarized dermoscopy: a dermoscopic pathological study. Br J Dermatol. 2009; 160(4): 801-809. doi: 10.1111/j.1365-2133.2008.08940.x   
5. Vázquez-López F, García-García B, Rajadhyaksha M, Marghoob AA. Dermoscopic rainbow pattern in non-Kaposi sarcoma lesions. Br J Dermatol. 2009; 161(2): 474-475. doi: 10.1111/j.1365-2133.2009.09225.x   
6. Toia F, Garbo G, Tripoli M, Rinaldi G, Moschella F, Cordova A. A systematic review on external ear melanoma. J Plast Reconstr Aesthet Surg. 2015; 68(7): 883-894. doi: 10.1016/j.bjps.2015.04.003   
7. Coit DG, Thompson JA, Algazi A, et al. NCCN Guidelines Insights: Melanoma, Version 3.2016. J Natl Compr Canc Netw. 2016; 14(8): 945-958.