Fig. c3t3P1: “Spitz nevus” in classical patterns is represented. The epidermis is irregularly hyperplastic. There are areas of edema in the papillary dermis. The tumor is wedge-shaped with the base abutting upon the epidermis. The apex extends to the deep margin of the biopsy. There is no evidence of lentiginous and junctional spread in the epidermis away from the dermal component. There are minimal perivascular infiltrates of lymphoid cells in the dermis at the advancing margin of the tumor. The lesion is symmetrical.

Fig. c3t3P2: In this classical “Spitz nevus,” fascicles of uniform, pale spindle cells rain down into the dermis. The epidermis is irregularly hyperplastic. The papillary dermis is widened and edematous. Vessels of the edematous papillary dermis are ectatic. The fascicles of neoplastic cells extend into the reticular dermis among collagen bundles. At the deep margin of this field, the fascicles are thinner than those near the dermal-epidermal interface (“maturation”).

Note: If we evoke the terminology (as related to a special system of logic) of common melanoma for the patterns in this field, the component in the reticular dermis would qualify as migrant vertical growth-like.

Fig. c3t3P3: Near the dermal-epidermal interface, the cells of classical “Spitz nevus” are usually spindle shaped; they show nuclear uniformity. The nuclei are enlarged; they show marginated chromatin, well-defined and smoothly contoured nuclear membranes, and a prominent nucleolus. The cells are loosely attached to their neighbors. Thin dendrites extend among the cells. Typical mitoses are acceptable at this level of a “Spitz nevus.”

Fig. c3t3P4: Atypia has been accepted in the category of “Spitz nevus;”the level of acceptance has compromised the utility of the concept, or raised questions regarding the accuracy of the related system of logic (a system in which attempts are made to accommodate nevoid qualities). The atypia in this example is moderately severe. There is nuclear pleomorphism with variation in nuclear size and staining. Upward migration of nests of cells and individual cells has also been accepted in the category. Even though this lesion is thin, it has migrated into the upper portion of the reticular dermis. At the advancing deep margin, individual neoplastic cells extend among the collagen bundles. Lymphoid infiltrates are mild. In the junctional component, there are scattered giant cells.

Note: Commonly, dermatopathologists have accepted properties in the “Spitz nevus” category that would be indicative of melanoma in the logic associated with common melanomas. Cytologic atypia and pleomorphism, upward migration of neoplastic cells in the epidermis, migrant vertical growth-like patterns are acceptable truth functions in one system of logic that has been promoted as having  relevance for the interpretations of “Spitz nevi.” Perhaps, much of the controversy which currently is associated with a diagnosis of “Spitz nevus” is related to some of us relying too fully on a faulty system of logic. As a starter, the Spitz lesion might be transferred from the nevoid category to the category of intermediate melanocytic neoplasia (i.e., minimal deviation melanoma, Spitz type). In anticipation of the objections to this recommendation, the lesion might be characterized as juvenile melanoma; the implications essentially would be the same.

Fig. c3t3P5: In this example, the patterns at the advancing margin are “Spitz nevus-like,” but the cells are cytologically atypical. There is little evidence of maturation. The individual cells among the collagen bundles are rounded or polygonal in outline; this alteration in cytologic features may relate to the acquisition of ameboid characteristics. The dermis is relatively free of inflammation. In many examples, as in this example, the cells migrating into the reticular dermis do not induce significant alterations in the pattern of collagen bundles of the reticular dermis. In some examples, the cells in the reticular dermis are associated with a desmoplastic response in the dermis.

Fig. c3t3P6: This is a classic “Spitz nevus” pattern. The lesion is distinguished by an inordinate number of giant cells. Papillary dermal edema and vascular ectasia are prominent features. There is some degree of nuclear atypia and pleomorphism.


[Spitz Lesions (c1t1)] [Index Page (c2t2)] ["Spitz Nevus" (c3t3)] ["Spitz Nevus" (c4t3)] [MDM (Spitz Type) (c5t3)] [MDM (Spitz Type) (c6t3)] [MDM (Spitz Type) (c7t3)] [Intermediate Neoplasia (c8t3)]