GENERAL  INDEX

Fig. c4t3P1: In this otherwise classical “Spitz nevus,” neoplastic cells have invaded the perineurium of a small peripheral nerve (neurotropic spread) near the deep margin of the lesion. The neoplastic cells are cytologically bland.

Fig. c4t3P2: In this otherwise classical “Spitz nevus,” neoplastic cells extend longitudinally in close contact with a dilated dermal lymphatic. One cell has disrupted the endothelium of the vessel; the cell projects into the lumen of the vessel. Among the collagen bundles, the neoplastic cells show maturation.

Fig. c4t3P3: In this variation in the patterns of a “Spitz nevus,” the cells extend into the dermis as individual units. They are supported by a specialized fibrous matrix; the patterns are desmoplastic. There is some degree of nuclear atypia and pleomorphism.

Fig. c4t3P4: The epidermis is represented in rather “stable” patterns. There is mild lentiginous melanocytic hyperplasia but the cells of the lentiginous component are small; they have dendritic qualities. In the dermis, round (epithelioid) cells are individually isolated in a specialized fibrous matrix (desmoplastic pattern). This pattern has been accommodated in the system of logic associated with “Spitz nevus.” It should be noted that the cytologic features are also  acceptable in the category of “halo nevus” showing dermal dysplasia. From the commonness of the cytologic features, it is tempting to extend the application of logic to other lesions such as MDM of dermal type; in this approach, MDM of dermal type would become a variant of “Spitz nevus.” Such a presumption would be an extension of the confusion that currently has compromised the category of “Spitz nevus.”

Fig. c4t3P5: The basic pattern is “Spitz nevus-like.” There is, however, nuclear atypia with variations in nuclear size and staining. Some of the nucleoli are large. Maturation is not a prominent feature. Lesions of this type might be characterized as “atypical:” perhaps, the patterns are better characterized as dysplastic (especially, since the latter designation carries such a potential to irritate certain “authorities”).

Note: the atypia in this lesion is difficult to accommodate in the category of “nevus.” It is easily accommodated in the category of  intermediate melanocytic neoplasia (MDM, variant and migrant vertical growth).

Fig. c4t3P7: The lesion has “Spitz nevus-like” features. Fascicles rain down into the dermis. They extend into the reticular dermis among collagen bundles. There is evidence of maturation near the deep margin of this field. Papillary dermal edema is not a feature. The technical quality of this section was poor. The patient was a child. See fig. c5t3P4 for pattern of recurrent  lesion.