In 1973, Dr. Martin C. Mihm, Jr. presented the finding that congenital melanocytic nevi, when viewed at low magnification, resemble superficial and deep perivascular dermatitis, forming the so-called “pseudoinflammatory” pattern. One year earlier, Dr. Richard A. Sagebiel had put forward the concept of “pseudovascular spaces” in melanocytic nevi. A retrospective look at these early studies confirms that alert observation at the microscope can lead to a deeper understanding of the fundamental biology underlying melanocytic tumors.