The stem describes a middle-aged woman hitting a lot of the ABCDEs of a melanoma. Assymetry: "irregular" Borders: "ill-defined margins" Color: "variegated black-tan pigmentation" Diameter: "increased size" (though they could also give you >6 mm Evolution over time: "past 6 months"

Additionally, the "pleomorphic, hyperchromatic" cells indicate it's malignant. Invasion into the papillary dermis is also a poor prognostic factor for melanoma.