Desmoplastic malignant melanoma: a report on two additional cases.

Two cases of desmoplastic malignant melanoma are described, bringing the total reported to nine. The first developed in a lentigo maligna melanoma and contains the seed of its local recurrence in the primary lesion. The second developed in a clinically apparent congenital nevus and unites the histologic features of the desmoplastic variant with the epithelioid and spindle cell histology of its primary, side by side in a local recurrence. Both primaries were clinically recognized pigmented lesions while the desmoplastic recurrences were amelanotic. Other clinico-pathologic characteristics of DMM as previously described, are confirmed. Light microscopic evidence is presented supporting the view that the desmoplastic reaction is a rare manifestation elicited by a highly invasive spindle cell component of malignant melanoma.