ABSTRACT
Melanotic pigmentation may occur in a variety of lesions unrelated to primary melanocytic disorders as a result of melanocyte colonization (p. 239) and hyperactivity of melanocytes present in the direct vicinity, or melanin synthesis by cells other than melanocytes. Although essentially outside the scope of this book, we include a brief discussion of these entities, some of which are rare and may be confused with melanoma. Those occurring in the skin are dealt with in Chapter 8; here, we shall discuss the extracutaneous ones (Table 14.1). We shall also briefly consider a number of mesenchymal tumors which display immunophenotypical similarities to melanocytic tumors but which are probably of nonmelanocytic lineage.
