Historical Perspective: Barnhill et al., 1995: "Metastasizing Spitz's Tumor"

 
Although Barnhill and colleagues considered a neoplasm that caused the death of a 15-year-old boy to be a melanoma, they regarded the neoplasms in two children, ages 2 and 7 years, who had lymph node metastases to be "metastasizing Spitz tumors." Of the "Spitz-like variant" and the "metastasizing Spitz tumors" (Fig. 13), Barnhill and colleagues wrote thus:
 
"This group of three tumors was defined by an epithelioid cell type that resembled the cells in Spitz nevi and a clinical course of metastasis including death in one case. The patients ranged in age from 2 to 15 years (median, 7 years). The one fatal melanoma developed on the neck of a 15-year-old boy. Histologically, the tumor contained a confluent mass of enlarged epithelioid cells and somewhat larger polygonal cells extending into the deep reticular dermis. . . . The morphologic appearance suggested a markedly atypical tumor with features of a Spitz nevus and a halo nevus.
 
Two patients developed lymph node metastases but were alive and well as of this writing on limited follow-up of 3 and 9 years, respectively, after excision of the primary tumor and lymphadenectomy. Histologically, these tumors exhibited features of Spitz's nevus but also asymmetry, deep extension, confluent nodules, prominent cellularity, diminished maturation, and some degree of cytologic atypia. . . . Cytologically, the cells in both tumors contained abundant eosinophilic cytoplasm with a ground glass appearance as noted in typical Spitz nevi. The cells also had polyangular contours and exhibited nuclei with enlarged and generally vesicular nuclei. The tumor developing on the arm of the 2-year-old female showed discohesive sheets of multinucleated giant cells, many of which were frankly bizarre in appearance. Neither lesion could be distinguished from the group of nine atypical Spitz-like tumors."

View Figure  		Fig. 13  Comment: The so-called metastasizing Spitz's tumor pictured by Barnhill et al. in their figure 7 can be told to be a melanoma because of the distribution of neoplastic melanocytes in the dermis where aggregations of them vary markedly in size and shape and many of them have become confluent to form a sheet. Although most of the neoplastic melanocytes have cytologic features reminiscent of those of Spitz's nevus, namely, large nuclei, abundant cytoplasm, and polygonal shape, as well as multinucleate forms, hyperchromasia of those nuclei and the presence, too, of melanocytes with small nuclei militate against this neoplasm being a Spitz's nevus. A malignant neoplasm of melanocytes is a melanoma, and one that metastasized like that shown here will result inevitably in the death of the patient.
 
Despite the acknowledgment by Barnhill and collaborators of features of melanoma histopathologically and despite metastases, those coworkers maintained, nevertheless, that the diagnosis of two of the neoplasms was "atypical Spitz-like tumor." The contagion generated by the AFIP, beginning with Helwig and followed by K. Smith et al., spread as far and wide as Nagoya (Nitta et al.) and Boston (Barnhill et al.).
 
Barnhill et al. also described nine neoplasms that they termed "atypical tumors with characteristics of Spitz nevus" and they did that in this sentence:
 
"These nine cases initially were diagnosed as malignant melanoma but on review they were judged to have features insufficient for unequivocal melanomas and were considered atypical tumors with characteristics of Spitz nevus."
 
Although Barnhill and associates noted peculiarities in these "atypical Spitz tumors," they persisted in contending that they were not melanomas. This is what they wrote about them:
 
" . . . [they] tended to be somewhat larger and to show more abnormalities than ordinary Spitz nevi. In general, asymmetry, deep extension (mean tumor thickness 4.36 mm), prominent cellularity, deeply located mitoses, occasional atypical mitoses, and cytologic atypia were noted. Some also had dermal cellular nodules with rounded 'pushing' margins. Others exhibited multifocal or plexiform finger-like infiltration of the dermis or subcutis along the inferior margins of the tumors. The latter morphologic pattern suggested some degree of order or growth control rather than loss of growth control in melanoma."