Atypical Pigmented lesion in an 81 yo Man

The patient is a light-complected Caucasian with Type I skin and a personal history of non-melanoma skin cancer.  His daughter has a history of melanoma.

He presented for a skin exam and was found to have an atypical pigmented lesion on his right shoulder.  He remembers that this lesion had been biopsied years ago at another facility and he was told it was fine.

O/E:  On the right shoulder there was a 1.2 mm in diameter irregularly pigmented macule with a play of color.  The dermatoscopic picture was worrisome and he was scheduled for an excisional biopsy.

Dermatoscopic image

Pathology:  The excisional biopsy showed a melanoma 0.3 mm thick, 0 mitoses per mm squared.  Free margins, but narrow.

(The old biopsy report from 2007 was reviewed.  This was a shave biopsy that showed a junctional nevus with mild to moderate atypia and margins were clear in the sections examined.)

Discussion:  The patient has a thin melanoma arising in the site of a previous biopsy.  This raises the question of whether shave biopsies of pigmented lesions are appropriate.  At any rate, a thin melanoma, 0.3 mm thick just requires a wide-local excisison with one cm margins.  Sentinel node biopsy is not indicated.  The patient will have regular skin exams from this point on.