Henrik F. Lorentzen, Kaare Weismann, Kristian Rossen, Henrik Klem Thomsen
DOI: 10.2340/00015555-0181

Dermatoscopy increases the accuracy of diagnosis of melanoma. An atypical vascular pattern may be an indicator of cutaneous malignant melanoma (CMM). During dermatoscopy of certain CMMs numerous ruby droplets of blood appear when the dermatoscope is pressed firmly against the lesion. The aim of this paper was to examine the histopathological background for this observation. CMMs from 8 patients showing the poppyfield sign, i.e. squirts of ruby blood droplets, were paired with 8 CMMs of equal Breslow thickness not showing this sign. The 16 CMMs were placed in an unsystematic sequence and presented to two dermato-pathologists who assessed the lesions independently for confirmation of Breslow thickness, Clark level, ulceration and presence of dilat­ed tumour vessels. There was no disagreement between the pathologists' assessments. Age of the patients and Breslow thickness of the cutaneous malignant melanoma were similar in the two groups. All 8 poppyfield CMMs had dilated tumour vessels compared with 25% (2/8) of the non-poppyfield CMMs (p< 0.007). Histological ulceration was observed in all poppyfield CMMs and none of the non-poppyfield CMMs (p< 0.001). The poppyfield bleeding sign is a dermatoscopic clue to dilated tumour vessels. It may be a dermatoscopic reflection of increased vascular density described in primary CMMs compared with adjacent skin and may also reflect the presence of primitive vessels in CMMs displaying increased fragility.