Tumours of fishes 30. Epidermoid carcinoma of the lower lip in the cichlid Hemichromis bimaculatus

Description of an ulcerated epidermoid carcinoma of the lower lip in an adult male of the Cichlid Hemichromis bimaculatus Gill. Histologically the tumour was composed of masses and strands of pleomorphic, columnar or polyhedral tumour cells, partly arranged in papillary pegs, which were supported by a vascular connective tissue stroma. The chromatin network of the nuclei was densely structured. The tumour tissue showed an invasive growth and had locally pierced the basement membrane. Emboli of tumour cells and metastases were lacking.