Role of histochemical stains in differentiating hemangioma and vascular malformation

Abstract

Background: Benign vascular lesions such as vascular malformation and hemangioma at times pose difficulty in diagnosis both for clinicians and pathologists. Vascular malformations are difficult to treat while hemangiomas resolve spontaneously in most instances. There are instances when vascular malformations, especially arteriovenous malformations (AVMs) have been misdiagnosed as hemangiomas and vice-versa. Clinical and radiological correlation with histopathological confirmation of these anomalies is important for the management of these lesionsAim: The aim was to study the histological characteristics of hemangiomas and vascular malformations and to study the utility of histochemical stains in their diagnosis. Materials and Methods: We retrospectively studied fifty cases retrieved from the records of Department of Pathology which were diagnosed as hemangioma (n=32) and vascular malformation (n=18) on Hematoxylin and Eosin (H and E) stain over a period of 18 months. The cases were analyzed based on findings of histochemical stains such as Verhoeff-van Gieson (VVG), Masson's trichrome (MT), and toluidine blue. Results: After reviewing all the cases with the use of histochemical stains, two of the three cases originally diagnosed as hemangioma turned out to be AVM and one to be venous malformation. An increased number of intra-lesional nerves were found in 16 of 19 cases of AVM and in both cases of venous and lymphatic malformation. Hemangiomas did not show increase in nerve bundles. Mast cells were found to be increased in proliferating hemangiomas and pyogenic granulomas as compared to AVMs. Conclusion: Hemangiomas and vascular malformations should be clearly differentiated to reduce the risk of treatment failure and recurrence. With the use of histochemical stains such as VVG, MT and toluidine blue, the diagnostic difficulty can be reduced and definitive diagnosis is possible.