c13t3P1: A somewhat anemic photo shows the pattern of the “common final pathway.” This is the pattern of marked melanocytic dysplasia as commonly manifested in the radial growth component of a superficial spreading melanoma. Superficial spreading melanoma (a lesion in vertical growth) is defined by this pattern in its radial growth component. The junctional qualities overshadow the lentiginous qualities. This is the type of lesion commonly characterized as “melanoma in situ” (“a lesion whose time has come”).
c13t3P2: The pattern in the epidermis is that of the common final pathway. The pattern in the dermis clearly is more complicated and cellular than any of the patterns defined for the dysplasias. Rounded nests of atypical cells are loosely but regularly spaced in the widened, fibrotic papillary dermis (pattern of lamellar fibrosis near the interface with the reticular dermis - arrested growth pattern in which nests of cells are entrapped in the fibrous matrix). Near the dermal-epidermal interface the stroma is loose and delicately fibrous (a permissive stroma which promotes the growth of tumor cells). The patterns are stratified but are not orderly in arrangement. At the interface with the reticular dermis, there is a band of inflamed fibrous tissue ( a boundary confining the tumor at this stage of neoplastic progression to the altered papillary dermis - classic level III pattern). The pattern in the dermis is classic variant vertical growth. The arrested pattern is a favorable prognostic finding; the permissive stroma is an unfavorable finding).
c13t3P3: Incomplete variant vertical growth-like patterns are evident to the right. To the left the expansile nodule is a component of typical vertical growth (a nodule confined to a widened papillary dermis).
c13t3P4: To the left, the pattern of the common final pathway is represented. Centrally and to the right, the loose spacing of nests of atypical cells in the widened papillary dermis is minimally sufficient to qualify as thin variant vertical growth. The vertical dimension would be less than 1 mm, and the lesion qualifies as borderline melanocytic neoplasia of indeterminate malignant potential.
c13t3P5: To the right, some of the patterns in the dermis qualify as incomplete variant vertical growth-like. The dense lymphoid infiltrates provide a halo nevus-like quality.
c13t3P6: The close spacing of nests of atypical cells in the dermis produce the pattern of thin typical vertical growth. In addition, some of the nests of cells extend into the upper portion of the reticular dermis (patterns of typical and migrant vertical growth). This thin borderline lesion metastasized.
c13t3P7: This is a portion of a radial growth component showing moderated dysplasia of lentiginous and junctional type. The papillary dermis is fibrotic. Lymphoid infiltrates are mild.
c13t3P8: The degree of dysplasia is moderate (go to Variant Vertical Growth (c14t3P1).
