Benign and malignant collision tumors of melanocytic skin lesions with hemangioma: Dermoscopic and reflectance confocal microscopy features.

Tognetti L, Cinotti E, Perrot JL, Campoli M, Fimiani M, Rubegni P.

Skin Res Technol. 2018 May;24(2):313-317. doi: 10.1111/srt.12432.


BACKGROUND:Though the combination/collision of nevi or lentigo simplex and hemangiomas is frequent, the malignant collision tumor melanoma-hemangioma is exceptional and can sometime clinically simulate a benign collision. To date, a series of collision tumors of hemangiomas associated with either benign or malignant melanocytic skin lesions (MSL) has yet to be studied by non-invasive imaging and clinico-pathologic correlates.

METHODS:We present 10 cases of patients with collision tumors of hemangioma with different MSL including: 2 in situ lentigo-maligna melanoma, 1 invasive melanoma, 5 melanocytic nevi, and 2 lentigo simplex. The clinical aspect along with the dermoscopic and reflectanceconfocal microscopy (RCM) features is described and compared with histopathologic findings.

RESULTS:Dermoscopic examination allows to recognize a dark ring in malignant collision melanoma-hemangioma and a jelly ring sign in benign collision of nevi/lentigo simplex-hemangioma. These peculiar features were confirmed by RCM and histopathologic findings.

CONCLUSION:Two simple dermoscopic clues confirmed by RCM features can be proposed to help distinguish between benign and malignant collisions tumors.

© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

KEYWORDS:collision tumors; cutaneous hemangioma; dermoscopy; lentigo-maligna melanoma; reflectance confocal microscopy

PMID: 29388348 DOI: 10.1111/srt.12432