In a 55-year-old male patient an irregular pigmented skin tumour (7x10mm) was presented on his left chest. He had skin type II, more than 50 small and more than 10 larger non suspicious nevi in clinic and dermoscopy. No history of a melanoma in his own history or his family.
In dermoscopy an asymmetric pigmented tumour with different homogeneous areas was visible: on the left and right area of the tumour an increased pigmentation with parts of network and starting streaks on the left side and peripheral globules and dots on the right side. In the centre a lost of homogenous structures with a starting regression was found. The tumour had light to dark brown colours and some distinct greyish areas, too.
In spite of an exact explanation with the help of the recorded image the patient refused the excision, but he agreed a follow-up image within two months.

After recording the follow-up image after two months, the patient insisted on an immediate excision ? but before he got the explanation of the changes: in dermoscopy an increase of the asymmetric pigmentation of the left area, however a decrease of the pigmentation on the right area and a clear increase of the regression area in the centre was visible. The tumour was increased in size (from 7x10mm to 9x11mm).

Histological diagnose
Severe dysplastic nevus

Remarks
Only the follow-up image convinced the patient.