has part has part has_part characteristic of characteristic of part of has modifier connective tissue type mast cell abnormal mast cell morphology abnormal dermal layer morphology abnormal dermal mast cell morphology MPheno.ontology MP:0008020 any structural anomaly of cells located in connective tissue of the dermis that contain numerous basophilic granules and release substances such as heparin and histamine in response to injury or inflammation morphology abnormal dermis connective tissue