Case Study

MyPath Melanoma

Atypical Melanocytic Proliferation on Sensitive Preauricular Cheek

A 65-year-old male presented with an atypical melanocytic proliferation near the left ear. Four sites of basal cell carcinoma and seborrheic keratosis were taken at the same visit.

A 65-year-old male patient was referred to dermatology for an atypical melanocytic proliferation near the left ear. The lesion was 7 mm in diameter, on left superior preauricular cheek. It was a reticulated, light tan macule, changing size and color. Clinical differential diagnosis included lentigo, lentigo maligna, and melanoma in-situ.


A comprehensive histopathological work-up included immuno-histochemical staining. Melan-A and S-100 confirmed the diagnosis of a nevus and Melan-A showed a confluence of melanocytes at and above the dermal-epidermal junction. Lentiginous epidermal hyperplasia and hyperpigmentation was noted. At the dermal-epidermal junction, discohesive nests of melanocytes and atypical melanocytic hyperplasia were identified. Superficial perivascular infiltrate with melanophages was identified in the underlying dermis.


A final diagnosis of Clark's nevus with unusual features was rendered with a recommendation to re-excise.



View in Pathfinder

Given the conflicting findings between the clinical impression (melanoma) and diagnosis (Clark's nevus with recommendation to re-excise), the malignant potential of the lesion was uncertain.


DiffDx-Melanoma resulted in a gene expression profile suggestive of a malignant neoplasm.


Due to the DiffDx-Melanoma test results, the dermatologist confirmed their clinical suspicion and was able to proceed with surgical excision using margins consistent with a melanoma in-situ. The patient management was adjusted to reflect more frequent follow-up appointments.

When it isn't possible to rule out a melanoma diagnosis through the pathology work-up alone, diagnostic GEP testing can provide additional information to obtain a more confident diagnosis and help guide the surgical margins.