Amelanotic acral melanomas: Clinicopathological, BRAF mutation, and KIT aberration analyses - 23/10/13
Abstract |
Background |
Amelanotic acral melanoma (AAM) is very rare and difficult to diagnose both clinically and pathologically. Complete-type AAM shows no black to brown pigmentation in the lesion, whereas incomplete-type AAM shows focal or subtle pigmentation. AAM has been the subject of few investigations.
Objectives |
We analyzed the clinicopathological features, BRAF mutations, and KIT aberrations in 35 Korean AAM cases.
Methods |
We included 28 cases of complete-type and 7 cases of incomplete-type AAM.
Results |
In all, 26 AAMs (45.7%) were located on the feet of patients, 21 of which (82.9%) showed ulceration. Sixteen cases developed in subungual areas. Nodular melanoma was the most common histopathological subtype (63.6%). The most frequent cell types affected were epithelioid and spindled. HMB-45 staining was strongly positive in 66.7% of AAMs; 4 (12.1%) were negative for HMB-45, and 3 of these were complete-type AAMs. Of 33 total patients, BRAF mutations were detected in 2 AAM cases, and KIT aberrations were present in 11 cases (33.3%). Four cases (12.1%), all of which were complete-type AAMs, had KIT mutations. KIT aberrations were weakly correlated with c-kit staining. Twenty patients were TNM stage I or II, and mean survival was 30.14 ± 4.54 months.
Limitations |
The study is limited by the small number of patients.
Conclusion |
Physicians should be aware of rare and hard-to-diagnose AAMs. We expect that tyrosine kinase inhibitors would be effective for KIT-mutated patients with complete-type AAMs.
Le texte complet de cet article est disponible en PDF.Key words : acral melanoma, amelanotic acral melanoma, amelanotic melanoma, BRAF mutation, HMB-45, KIT mutation, prognosis
Abbreviations used : AAM, AJCC, PCR
Plan
Supported by a grant (CRI11077-22) from the Chonnam National University Hospital Research Institute of Clinical Medicine and by the 2012 Third AmorePacific/KDF Research Award. |
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Conflicts of interest: None declared. |
Vol 69 - N° 5
P. 700-707 - novembre 2013 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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