Complex sentence: A related category of melanocytic proliferation is "superficial atypical melanocytic proliferations of uncertain significance" (SAMPUS), which includes junctional melanocytic proliferations and proliferations in the epidermis and papillary dermis that are not accompanied by tumorigenic cell mitosis.
Split into simpler sentences: A related category of melanocytic proliferation is "superficial atypical melanocytic proliferations of uncertain significance" (SAMPUS). The SAMPUS category includes certain atypical junctional melanocytic proliferations and proliferations in both the epidermis and papillary dermis that are not accompanied by intradermal tumorigenic architecture or cell mitosis.