ABSTRACT: Morphology, cell composition and histochemistry of a gross mantle tumor of Modiolus difficilis are described. The well-differentiated tumor contained numerous cells atypically rich in neutral polysaccharides and bundles of fibrous tissue and muscles. Mitotic activity of the cells of the tumor base ranged from 0 to 0.8%. Architectural disorganization, the presence of collagen and necrotic cells, cellular and nuclear changes, the absence of a protective epithelium and hemocytic infiltration of the tumor base permitted the tumor to develop as a result of chronic irritation and inflammation of the anomalous developing mantle.

KEY WORDS: Tumor · Proliferation · Mitotic index · Mantle · Mussel

Published in DAO Vol. 29, No. 2 (1997) on May 22
ISSN: 0177-5103. Copyright © Inter-Research, Oldendorf/Luhe, 1997