Benign vascular anomalies: A transition from morphological to etiological classification

Area of Science:

• Pathology
• Vascular Biology
• Histopathology

Background:

• Benign vascular anomalies are classified by the International Society for the Study of Vascular Anomalies (ISSVA) into tumors and malformations.
• Accurate classification impacts therapeutic and prognostic outcomes.
• Misuse of terms like "hemangioma" leads to incorrect patient treatment.

Purpose of the Study:

• To evaluate histomorphological and immunohistochemical features for precise histopathological classification of benign vascular anomalies.
• To differentiate vascular tumors from malformations using established criteria and specific markers.

Main Methods:

• Review and reclassification of 48 benign vascular anomaly cases based on ISSVA criteria.
• Histopathological analysis using endothelial morphology, mitotic activity, intralesional nerve bundles, inflammation, and vessel type.
• Immunohistochemical staining for GLUT-1, WT-1, and Ki-67.

Main Results:

• 33 cases of vascular malformations and 15 cases of vascular tumors (7 infantile hemangiomas, 4 non-involuting congenital hemangiomas, 4 pyogenic granulomas) were diagnosed.
• Endothelial cell morphology, mitotic activity, and intralesional nerve bundles significantly differentiated hemangiomas from malformations (p < 0.001).
• GLUT-1 and Ki-67 reliably distinguished infantile hemangioma from vascular malformations (p < 0.001).

Conclusions:

• The ISSVA classification is reliably applicable to histopathology for benign vascular anomalies.
• Histopathological features and immunohistochemistry are essential for accurate diagnosis.
• Integration of clinical and radiological findings is vital for comprehensive case interpretation.