Historical Perspective: Spatz and Avril, 1998

 
In 1998, Spatz and Avril wrote about "Melanoma in childhood: Review and perspectives."71 The criteria they considered most helpful for accurate histopathological diagnosis of melanoma were these:
 
"Whatever the histological type, features appearing to be most useful for distinguishing melanomas from nevi are large size (i.e.,>7 mm), ulceration, high mitotic activity (>4 mitoses/mm2), mitoses in the lower third of the lesion, asymmetry, poorly demarcated lateral borders, lack of maturation, dusty melanin, and marked nuclear polymorphism."
 
Spatz and Avril also recognized that some melanomas "simulate Spitz's nevus" and they expressed their thoughts about them thus:
 
"From time to time melanomas exhibit a combination of features commonly regarded as being diagnostic of Spitz's nevus. These are large epithelioid cells, spindle cells arranged in fascicles, vascular ectasia, and edema in the upper dermis . . . Some of these criteria can be qualified as major as they appear highly discriminating in most of the studies. These include deep mitoses (i.e., more than 3 mitoses in the lower third), high mitotic activity (i.e., >4/mm2), and marked nuclear atypia. Other criteria favoring the diagnosis of melanoma include ulceration, asymmetry, deep extension, large size, abnormal mitoses, high cellularity, lack of maturation, and dusty melanin. Because of the lack of specific criteria for melanoma versus Spitz's nevi, it has been proposed that atypical Spitz tumors be categorized into low-risk or high-risk groups based on the accumulation of abnormal features."
 
It is not accurate to state that there is "lack of specific criteria for melanoma versus Spitz's nevi"; such criteria are available for making that distinction histopathologically in postpubescents and, in the vast majority of instances, they work (Table 1: Criteria for Differential Diagnosis Histopathologically of Spitz's nevus from Melanoma in Postpubescents).Of course errors are made in diagnosis, despite the availability of criteria that, for the most part, are highly workable, one of the chief reasons for the stumble being that diagnosis histopathologically is 100% subjective and histopathologists, being 100% human, are bound, on occasion, to misinterpret a Spitz's nevus as a melanoma—and vice versa.