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Amelanotic metastatic cutaneous melanoma* * Work performed at Brasilia University Hospital – Brasilia University (HUB-UnB) – Brasília (DF), Brazil.

Melanoma metastático amelanótico cutâneo

Abstracts

Dermatoscopy of melanocytic lesions has guided the decision of when or not to biopsy a lesion. The use of this tool has increased clinical examination's sensitivity and specificity in 89% and 96% respectively. However, dermatoscopic evaluation of amelanotic or hypomelanotic melanomas, as well as metastases, can be difficult. There is still no standardization for the analysis of these pathologies, which relies mostly on their vascular pattern. We describe the dermatoscopy of acral metastatic amelanotic melanoma.

Dermoscopy; Melanoma, amelanotic; Neoplasm metastasis


A dermatoscopia das lesões melanocíticas tem auxiliado na decisão de biopsiar ou não uma lesão. A utilização desta ferramenta aumentou a sensibilidade e a especificidade do diagnóstico para 89% e 96%, respectivamente. No entanto, a avaliação dermatoscópica de melanomas amelanóticos ou hipomelanóticos, bem como a de metástases cutâneas, pode ser difícil. Ainda falta uma padronização para a análise destas patologias, que se baseia, majoritariamente, no seu padrão vascular. Descreve-se a dermatoscopia de melanoma metastático amelanótico acral.

Dermoscopia; Melanoma amelanótico; Metástase neoplásica


INTRODUCTION

This is a thirty-eight-year-old female patient, with history of a hyperchromic-blackened plantar spot on the right foot since birth. Two years ago, the lesion started to grow in size and display heterogeneous color, asymmetric edges and ulceration, being then biopsied. Histopathology examination revealed melanoma, measuring 17x10 mm, with Breslow thicker than 3mm and positive surgical margins.

The patient was submitted to surgical expansion of margins with resection of a residual nodular melanoma. Margins were free at 7 mm from the neoplasm and sentinel lymph node was positive, which lead at the time to the choice of lymph node dissection, local radiotherapy and adjuvant treatment with interferon. PET / CT exam revealed no metastases in other organs.

Two months ago, a normochromic papule was identified, measuring 4mm and located in the plantar area at a distance of 5 mm from the primary tumor's resection scar (Figure 1).

FIGURE 1
Pinkish papule with 3 mm of diameter, located 5 mm from the surgical scar

At dermoscopy, performed with DermLite®, Pro model HR device (3Gen - San Juan Capistrano, CA), milky-red areas and irregular vessels arranged in corkscrew, spots and hair clip patterns throughout the lesion were detected (Figure 2). Pigmented network, dots or globules were not detected.

FIGURE 2
At dermoscopy, polymorphic vessels are seen – in corkscrew (circle), in points and lines (arrows) – besides milky-red areas

An excisional biopsy was performed, revealing melanoma with Breslow thickness greater than 4 mm without ulceration, mitotic index of 8/mm2 and peripheral and deep surgical margins affected by the malignancy (Figure 3). The patient underwent another surgery for margin expansion and restaging of the tumor.

FIGURE 3
Histopathology: atypical melanocytes showing bizarre mitosis, nuclei with varying sizes, prominent nucleoli and pigment absence

DISCUSSION

Dermoscopy has its established use in the diagnosis of melanocytic lesions and is a promising tool in monitoring therapeutic responses.22. Schiffner R, Schiffner-Rohe J, Vogt T, Landthaler M, Wlotzke U, Cognetta AB, et al. Improvement of early recognition of lentigo maligna using dermatoscopy. J Am Acad Dermatol. 2000;42:25-32.,33. Costa MC, Abraham LS, Barcaui CB. Lentigo maligna treated with topical imiquimod: dermatoscopy usefulness in clinical monitoring. An Bras Dermatol. 2011;86:792-4.,44. Grazzini M, Stanganelli I, Rossari S, Gori A, Oranges T, Longo AS, et al. Dermoscopy, confocal laser microscopy, and hi-tech evaluation of vascular skin lesions: diagnostic and therapeutic perspectives. Dermatol Ther. 2012;25:297-303. On the other hand, lesions with complete or partial absence of pigment still represent a diagnostic challenge both in terms of clinical and dermoscopic standpoints.44. Grazzini M, Stanganelli I, Rossari S, Gori A, Oranges T, Longo AS, et al. Dermoscopy, confocal laser microscopy, and hi-tech evaluation of vascular skin lesions: diagnostic and therapeutic perspectives. Dermatol Ther. 2012;25:297-303.

The amelanotic and hypomelanotic melanomas are characterized by complete or partial absence of pigment and account for 2-8% of all melanomas.44. Grazzini M, Stanganelli I, Rossari S, Gori A, Oranges T, Longo AS, et al. Dermoscopy, confocal laser microscopy, and hi-tech evaluation of vascular skin lesions: diagnostic and therapeutic perspectives. Dermatol Ther. 2012;25:297-303.,55. Jaimes N, Braun RP, Thomas L, Marghoob AA. Clinical and dermoscopic characteristics of amelanotic melanomas that are not of the nodular subtype. J Eur Acad Dermatol Venereol. 2012;26:591-6. Diagnosis is a difficult task, since they can be confused with other lesions such as Bowen's disease, actinic keratoses, sebaceous hyperplasia, basal cell carcinoma, dermal nevus, among others.11. Zalaudek I, Kreusch J, Giacomel J, Ferrara G, Catricalà C, Argenziano G. How to diagnose nonpigmented skin tumors: a review of vascular structures seen with dermoscopy: part I. Melanocytic skin tumors. J Am Acad Dermatol. 2010;63:361-74.

Dermoscopic analysis of these lesions does not have a universally accepted standardization.66. de Giorgi V, Sestini S, Massi D, Maio V, Giannotti B. Dermoscopy for "true" amelanotic melanoma: a clinical dermoscopic-pathologic case study. J Am Acad Dermatol. 2006;54:341-4. The lack of pigmented network, dots, globules, and whitish-blue veil hinders the diagnosis, which becomes dependent mainly on the analysis of vascular pattern.44. Grazzini M, Stanganelli I, Rossari S, Gori A, Oranges T, Longo AS, et al. Dermoscopy, confocal laser microscopy, and hi-tech evaluation of vascular skin lesions: diagnostic and therapeutic perspectives. Dermatol Ther. 2012;25:297-303.,55. Jaimes N, Braun RP, Thomas L, Marghoob AA. Clinical and dermoscopic characteristics of amelanotic melanomas that are not of the nodular subtype. J Eur Acad Dermatol Venereol. 2012;26:591-6.,77. Pizzichetta MA, Talamini R, Stanganelli I, Puddu P, Bono R, Argenziano G, et al. Amelanotic/hypomelanotic melanoma: clinical and dermoscopic features. Br J Dermatol. 2004;150:1117-24.

The format of vessels depends on the thickness of the melanoma and its layout.88. Jaimes N, Halpern JA, Puig S, Malvehy J, Myskowski PL, Braun RP, et al. Dermoscopy: an aid to the detection of amelanotic cutaneous melanoma metastases. Dermatol Surg. 2012;38:1437-44. Vessels that are disposed perpendicularly are seen as points, while longitudinal vessels are viewed in a linear fashion.11. Zalaudek I, Kreusch J, Giacomel J, Ferrara G, Catricalà C, Argenziano G. How to diagnose nonpigmented skin tumors: a review of vascular structures seen with dermoscopy: part I. Melanocytic skin tumors. J Am Acad Dermatol. 2010;63:361-74.,88. Jaimes N, Halpern JA, Puig S, Malvehy J, Myskowski PL, Braun RP, et al. Dermoscopy: an aid to the detection of amelanotic cutaneous melanoma metastases. Dermatol Surg. 2012;38:1437-44. In thin melanomas, vessels in points are more common, while in melanomas with Breslow thickness greater than 1mm, the vascular disposition tends to be mixed with irregular linear vessels, hair clip, corkscrew and point patterns.11. Zalaudek I, Kreusch J, Giacomel J, Ferrara G, Catricalà C, Argenziano G. How to diagnose nonpigmented skin tumors: a review of vascular structures seen with dermoscopy: part I. Melanocytic skin tumors. J Am Acad Dermatol. 2010;63:361-74. Melanoma metastases follow the same pattern of presentation, with high prevalence of corkscrew pattern vessels in thick tumors.11. Zalaudek I, Kreusch J, Giacomel J, Ferrara G, Catricalà C, Argenziano G. How to diagnose nonpigmented skin tumors: a review of vascular structures seen with dermoscopy: part I. Melanocytic skin tumors. J Am Acad Dermatol. 2010;63:361-74. In the present case, because it was a thicker lesion confirmed by histopathology, we observed an heterogeneous vascular pattern and the presence of vessels in corkscrew, raising the suspicion of a metastatic lesion.

Besides the vascular pattern, milky-red areas and crystalline structures or chrysalis can be identified. The milky-red areas correspond to polygonal pinkish zones separated by white blurred structures, found in about 50% of amelanotic melanomas.11. Zalaudek I, Kreusch J, Giacomel J, Ferrara G, Catricalà C, Argenziano G. How to diagnose nonpigmented skin tumors: a review of vascular structures seen with dermoscopy: part I. Melanocytic skin tumors. J Am Acad Dermatol. 2010;63:361-74.,77. Pizzichetta MA, Talamini R, Stanganelli I, Puddu P, Bono R, Argenziano G, et al. Amelanotic/hypomelanotic melanoma: clinical and dermoscopic features. Br J Dermatol. 2004;150:1117-24.,88. Jaimes N, Halpern JA, Puig S, Malvehy J, Myskowski PL, Braun RP, et al. Dermoscopy: an aid to the detection of amelanotic cutaneous melanoma metastases. Dermatol Surg. 2012;38:1437-44. Chrysalis, are bright white structures seen on polarized dermoscopy that possibly correspond to changes in papillary dermis collagen and are also less frequently found.11. Zalaudek I, Kreusch J, Giacomel J, Ferrara G, Catricalà C, Argenziano G. How to diagnose nonpigmented skin tumors: a review of vascular structures seen with dermoscopy: part I. Melanocytic skin tumors. J Am Acad Dermatol. 2010;63:361-74. In 2008, Shultz and colleagues further described lacunae or saccular structures in amelanotic melanoma metastases with a specificity of 99%.88. Jaimes N, Halpern JA, Puig S, Malvehy J, Myskowski PL, Braun RP, et al. Dermoscopy: an aid to the detection of amelanotic cutaneous melanoma metastases. Dermatol Surg. 2012;38:1437-44.,99. Schulz H. Epiluminescence microscopy features of cutaneous malignant melanoma metastases. Melanoma Res 2000;10:273-80.

Another peculiarity of the dermoscopy of these lesions is the way it should be performed, which should preferably be with polarized dermoscopy and without any contact with the lesion. Contact between the lens and the tumor can cause compression of vessels, which hinders their visualization. If contact dermoscopy is the option, the use of ultrasound gel can attenuate the pressure on the lesion in comparison to the use of alcohol or immersion oil.11. Zalaudek I, Kreusch J, Giacomel J, Ferrara G, Catricalà C, Argenziano G. How to diagnose nonpigmented skin tumors: a review of vascular structures seen with dermoscopy: part I. Melanocytic skin tumors. J Am Acad Dermatol. 2010;63:361-74.

Although controlled studies on the dermoscopy of these lesions are lacking, its use seems to emerge as an indispensable tool for the evaluation and monitoring of these patients, increasing the sensitivity and specificity of the clinical examination, which can positively affect the prognosis of the subjects under evaluation.

REFERENCES

  • 1
    Zalaudek I, Kreusch J, Giacomel J, Ferrara G, Catricalà C, Argenziano G. How to diagnose nonpigmented skin tumors: a review of vascular structures seen with dermoscopy: part I. Melanocytic skin tumors. J Am Acad Dermatol. 2010;63:361-74.
  • 2
    Schiffner R, Schiffner-Rohe J, Vogt T, Landthaler M, Wlotzke U, Cognetta AB, et al. Improvement of early recognition of lentigo maligna using dermatoscopy. J Am Acad Dermatol. 2000;42:25-32.
  • 3
    Costa MC, Abraham LS, Barcaui CB. Lentigo maligna treated with topical imiquimod: dermatoscopy usefulness in clinical monitoring. An Bras Dermatol. 2011;86:792-4.
  • 4
    Grazzini M, Stanganelli I, Rossari S, Gori A, Oranges T, Longo AS, et al. Dermoscopy, confocal laser microscopy, and hi-tech evaluation of vascular skin lesions: diagnostic and therapeutic perspectives. Dermatol Ther. 2012;25:297-303.
  • 5
    Jaimes N, Braun RP, Thomas L, Marghoob AA. Clinical and dermoscopic characteristics of amelanotic melanomas that are not of the nodular subtype. J Eur Acad Dermatol Venereol. 2012;26:591-6.
  • 6
    de Giorgi V, Sestini S, Massi D, Maio V, Giannotti B. Dermoscopy for "true" amelanotic melanoma: a clinical dermoscopic-pathologic case study. J Am Acad Dermatol. 2006;54:341-4.
  • 7
    Pizzichetta MA, Talamini R, Stanganelli I, Puddu P, Bono R, Argenziano G, et al. Amelanotic/hypomelanotic melanoma: clinical and dermoscopic features. Br J Dermatol. 2004;150:1117-24.
  • 8
    Jaimes N, Halpern JA, Puig S, Malvehy J, Myskowski PL, Braun RP, et al. Dermoscopy: an aid to the detection of amelanotic cutaneous melanoma metastases. Dermatol Surg. 2012;38:1437-44.
  • 9
    Schulz H. Epiluminescence microscopy features of cutaneous malignant melanoma metastases. Melanoma Res 2000;10:273-80.
  • *
    Work performed at Brasilia University Hospital – Brasilia University (HUB-UnB) – Brasília (DF), Brazil.
  • Financial Support: none

Publication Dates

  • Publication in this collection
    Nov-Dec 2013

History

  • Received
    16 Oct 2012
  • Accepted
    25 Oct 2012
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