Lobular capillary haemangiomas in young horses

Area of Science:

• Veterinary Pathology
• Dermatology
• Oncology

Background:

• Cutaneous haemangiomas are vascular tumors affecting animals.
• Understanding their specific characteristics in horses is crucial for diagnosis and treatment.
• Previous classifications may not fully capture the unique morphology observed in equine cases.

Purpose of the Study:

• To describe the histopathological features of cutaneous haemangiomas in young horses.
• To propose a specific nomenclature for these equine vascular lesions.
• To differentiate these lesions from other proliferative conditions.

Main Methods:

• Histopathological examination of seven equine cutaneous haemangioma cases.
• Detailed morphological analysis of vascular structures, cellularity, and tissue architecture.
• Comparison with known veterinary and human vascular and proliferative lesions.

Main Results:

• Lesions characterized by scattered, well-demarcated, unencapsulated lobules of capillary-sized vascular structures.
• Fibrous septa separated vascular lobules.
• One case showed a more cellular variant with minor vasoformative capacity.
• Morphological features are comparable to bovine cutaneous angiomatosis and human pyogenic granuloma.
• Lesions are considered vascular tumors, not hamartomas or granulation tissue.
• The term "lobular capillary haemangioma" is proposed for this equine condition.
• One tumor exhibited combined capillary and cavernous vascular structures.

Conclusions:

• Equine cutaneous haemangiomas present as lobular capillary haemangiomas.
• These lesions are distinct vascular tumors with specific histopathological features.
• The proposed terminology aids in accurate classification and understanding of these equine skin tumors.