Introduction: Pyogenic granuloma (PG) is a benign vascular tumor of skin and mucous membranes which more commonly develops following trauma, laser treatment, or pregnancy. Although infrequently, PG may arise spontaneously in richly vascularized area due to arteriovenous anastomoses found in Port Wine Stain (PWS). Case Presentation: A 44-year old woman presented with a solitary, dome-shaped, 7x7 mm nodule covered with crusts and scales emerging on sharply demarcated erythematous macule extending from temporal to maxillary part of the left side of her face. The distribution was aligned with the innervation of the second branch of trigeminal nerve. We performed shave biopsy for treatment and followed with 30% TCA to treat the bleeding. The obtained specimen reveled acanthosis, rete ridges lengthening, and capillary proliferation under histopathology examination, confirming the diagnosis of PG. However, the specimen was not enough to confirm the diagnosis of PWS histologically. Discussion: The congenital defect in PWS may have increased number arteriovenous anastomoses that lacks capillary bed to deliver blood to surrounding tissue. The decrease in oxygen delivery may induce angiogenesis that may contribute to the development of PG

pyogenic granuloma

port wine stain

shave biopsy