Fig. P15-46 (to the left): At higher magnificatin, the cells form fascicles as well as rounded nests. There are spotty lymphoid infiltrates among the nests of tumor cells. The loose spacing of the nests of cells is a feature of variant vertical growth but in this example, the nests infiltrate the reticular dermis. This distribution of the nests of cells might be better characterized as migrant vertical growth. In the nests, nuclei are widely spaced; the cells appear to have more cytoplasm than the cells of the earlier specimen.

Fig. P15-47 (to the right): Focally, the nests of cells are crowded and some are back to back. For the most part, the nests sit among pre-existing collagen bundles of the reticular dermis. At this magnification, it is apparent that the tumor cells are more spindle shaped than rounded in outline. In addition, the nuclei of the tumor cells are elaongated rather than rounded.

Fig. P15-48 (to the left): Rather bland spindle cells form a fascicle. The cells have pale, acidophilic cytoplasm and rather uniform, elongated nuclei. The tumor cells are loosely attached to their neighbors. A small collection of lymphocytes and histiocytes (host immune response) is present in the adjacent dermis. Complex fascicular patterns (micro-plexiform patterns) are evident  in this field and in Fig. P15-47.

Fig. P15-49 (to the right): The material from the recent excision is represented in this field. The epidermis centrally is slightly acanthotic and rete patterns are effaced. There is a zone of pale connective tissue which is outlined by blue arrows. This zone is composed of organizing granulation tissue in the site of the recent biopsy. Nests of tumor cellls are represented to the right  of the zone of pale connective

Fig. P15-50 (to the left): The zone of repair is represented in the upper portion of the reticular dermis and presses upon a slightly hyperplastic epidermis. In this zone, there are perivascular infiltrates of lymphocytes. The aggregates of tumor cells have a micro-plexiform quality. In them, small nests and fascicles are closely spaced. Pigment deposits are present in the adjacent lymphoid infiltrates.

Fig. P15-51 (to the right): In this field, a nodule of tumor bulges into the subcutaneous fat. It is mostly outlined by a condensati0n of fibrous tissue (blue arrows). This condensation of fibrous tissue, although of uncertain nature, could represent a thickened perineurium. The tumor nodule then might represent intraneural growth (neurotropism). In the region of the red arrows, the tumor, in ill-defined fascicular patterns, extends into the fat with a dense lymphoid infiltrate at the interface. The pattern  of the tumor in the area of the lymphoid infiltrates is

Fig. P15-52 (to the left): The tumor extends into the fat in irregular patterns beyond the confines of the lymphoid infiltrate. None of these nest could be positively identified as evidence of neurotropic spread.