Identification of equine cutaneous lymphangioma by application of a lymphatic endothelial cell marker.

This research study discusses the diagnosis of cutaneous lymphangioma in a horse, a rare skin tumour that was identified through the use of a lymphatic endothelial cell marker.

Diagnosis of the Condition

• An adult horse was examined and diagnosed with a mass within the dermis and subcutis of the right forelimb.
• The diagnosis was noticed after the horse died and a post-mortem examination was performed. It revealed a significant enlargement in the subcutis of the right forelimb, reaching up to the pectoral muscles.
• The diagnostic examination showed the dermis and subcutis were diffusely infiltrated by cells that resembled endothelial cells, which formed irregular channels and cavernous spaces.

Confirmation of the Tumour

• An immunohistochemical examination was carried out to identify the type of the tumour.
• The endothelial-like cells were revealed to express vimentin, factor VIII-related antigen and PROX-1. It confirmed the tumour as a lymphangioma.

Understanding of the Tumour Structure

• An ultrastructural analysis, which provides more detailed imaging on a cellular level, was done to observe the structure of the tumour.
• The analysis found that the cavernous spaces were lined by a discontinuous endothelium. This is a unique formation of stretched cells that lacked any basement membrane, an essential component that usually supports cells.

In conclusion, the study presents a thorough examination and identification of a case of equine cutaneous lymphangioma, a rare tumour, using a lymphatic endothelial cell marker. This detailed inspection allowed researchers to understand the structure and nature of the tumour better.