Angiosarcoma of the Scalp Presenting With Eyelid Edema: A Diagnostic Pitfall of Eyelid Biopsy

Angiosarcoma of the scalp is a rare but aggressive vascular malignancy that may present with nonspecific clinical findings, potentially leading to delayed diagnosis. Eyelid edema is an uncommon initial manifestation and has been suggested to result from direct tumor infiltration or lymphatic obstruction. A 74‐year‐old woman presented with progressive bilateral eyelid edema and subtle erythema on the frontal scalp without nodules or ulceration. Initial biopsies from the eyelid and scalp lesions revealed no malignant findings. Histopathological examination of the eyelid lesion demonstrated marked interstitial edema without tumor cells or apparent lymphatic dilation. Immunohistochemical staining for CD31 and D2‐40 did not reveal tumor cell infiltration. Two months later, a second biopsy from a newly developed scalp nodule revealed angiosarcoma. Retrospective review of the initial scalp biopsy subsequently identified subtle angiosarcoma cells that had been overlooked. This case highlights a diagnostic pitfall in scalp angiosarcoma presenting with eyelid edema. Eyelid edema may occur without direct tumor infiltration, and a negative eyelid biopsy does not exclude angiosarcoma. Careful follow‐up, repeated biopsy from appropriate sites, and close clinicopathological correlation are essential for early diagnosis.