Unrecognized desmoplastic malignant melanoma. Desmoplastic melanoma can be banal in appearance, with 70% appearing amelanotic, he said. These lesions may only present as firmness in the subcutaneous tissue. For "banal" appearing firm lesions on chronically sun-damaged skin, suspicion should be raised if the lesions are symptomatic, growing, are associated with a lentigo maligna, or reveal irregular vessels with dermoscopy, said Dr. Marghoob.
Metastatic melanoma with unknown primary or recurrence of melanoma. Whenever possible, do not remove seemingly benign lesions and discard them, he said. Also, be careful and selective about the use of liquid nitrogen or a laser on lesions that have not been confirmed to be benign through biopsy.
He noted that cases of assumed benign lesions that recur after ablation (via liquid nitrogen, curettage, or laser), may ultimately prove to be melanoma on histopathology. Furthermore, in the unlikely event that a patient develops metastatic melanoma with an unknown primary, it may be presumed that one of the ablated lesions may have been the primary.
Dr. Marghoob disclosed having no conflicts of interest. SDEF and this news organization are owned by Elsevier.
A partial biopsy was performed of this lesion which had clinical features of melanoma. The pathology analysis was reported as a Clark’s nevus (this area is the white scar on the left upper portion of the lesion). Due the clinical-pathology discordance the clinician decided to excise the lesion. As can be seen from the histology, this lesion was a melanoma and depending on the location of a partial biopsy the results can range from a Clark’s nevus to melanoma in situ to microinvasive to deeply invasive melanoma. Photo courtesy Dr. Ashfaq Marghoob.