abnormal pineal gland morphology abnormal pinealocyte morphology MP:0013359 MPheno.ontology abnormal chief cell of corpus pineale abnormal parenchymatous cell of corpus pineale abnormal pineal parenchymal cell morphology abnormal pineocyte morphology abnormal pinocyte morphology any structural anomaly of the principal cell of the pineal gland, characterized by two or more long cell processes ending in bulbous expansions that terminate in perivascular spaces surrounding capillaries; pinealocytes are secretory cells organized into cords and clusters resting on a basal lamina and surrounded by connective tissue, blood vessels lined by fenestrated endothelial cells, and nerves; their cytoplasm contains abundant mitochondria and multiple synaptic ribbons that are randomly distributed; the primary function of the pinealocytes is the secretion of melatonin; pinealocytes receive a direct innervation from sympathetic neurons that form recognizable synapses