Canine histiocytic syndrome manifested as ulcerative gastroenterocolitis, skin lesions and lymphadenopathy – a case report

Abstract

Histiocytic syndrome was diagnosed in a 7-year-old boxer bitch using histological and immunohistochemical methods. Necropsy confirmed the presence of enlarged superficial lymph nodes, two large ulcerated oval cutaneous masses one on the left lateral thoracic wall and one near to the vulva. In the gastrointestinal tract there were multiple ulcers apparently overlying nodules located in the submucosa of stomach, ulcers in the ileocaecal valve, and enlargement of lymphoid nodules in the small intestine manifested ulcerative gastroenteritis. Histologically, the thoracic wall mass showed infiltration of the tissue by macrophages with cytoplasmic vacuoles. The vacuoles contained PAS-positive polysaccharides. The macrophages were positive for alpha-1-antitrypsin and lysozyme by immunostaining. Lysozyme is a marker for phagocytic macrophages/histiocytes and may be used to confirm cells of this lineage in cases when there is any doubt.