Histopathological features of the pyogranulomatous dermatitis in porpoise PP121130. A Keratin pearl, consisting of concentric rings of squamous cells with progressive keratinization towards the centre, within the epidermal layer. B There is infiltration of many neutrophils and macrophages at the border between keratin pearl and surrounding epidermis. C There is an aggregate of bacteria (in between arrowheads) among the infiltrating inflammatory cells. Haematoxylin and eosin. Original magnifications: 20 X objective (A); 10 X objective (B); 100 X objective (C).