This pathology video details a case of an aggressive vascular malignancy, Angiosarcoma, presenting as a violaceous nodule on the nose of a 70-year-old man with a history of rhinophyma. The microscopic examination of the large excision revealed hallmark features including striking cellular atypia, pleomorphism, and infiltrative vascular channel formation. A classic diagnostic clue highlighted is the tendency of the malignant endothelial cells to wrap around and dissect individual dermal collagen bundles. The presentation strongly emphasizes the necessity of distinguishing Angiosarcoma—an aggressive tumor with high mortality—from Kaposi Sarcoma (a more indolent condition), often requiring confirmation via HHV8 immunohistochemistry, especially in head and neck locations. The video also discusses the limitations of superficial biopsies and the utility of vascular immunostains like ERG and D2-40 for accurate diagnosis.
Angiosarcoma: A Challenging Head and Neck Malignancy
0:03 Case Presentation: The subject is a 70-year-old man presenting with a violaceous nodule on his nose, complicated by a history of rhinophyma.
1:13 Diagnosis Confirmed: Histology of the large excision shows atypical, hyperchromatic epithelioid/spindled cells lining infiltrative vascular channels, confirming the diagnosis of Angiosarcoma.
1:19 Epidemiology: Angiosarcoma of the head and neck typically occurs in elderly, sun-damaged patients, distinguishing it from cases seen post-radiation (often in the breast).
1:56 Key Histologic Features: The malignancy is defined by infiltrative growth, marked cellular atypia, and pleomorphism.
2:32 Classic Infiltrative Pattern: A highly characteristic feature is the atypical endothelial cells wrapping around and dissecting individual dermal collagen bundles in the reticular dermis, digging deep into the tissue.
3:06 Differential Diagnosis (DDx) with Kaposi Sarcoma (KS): Unlike KS, Angiosarcoma exhibits striking atypia and pleomorphism. If a Kaposi-like lesion is found on the head/neck of an older patient, the pathologist should favor Angiosarcoma until proven otherwise with a positive HHV8 stain.
4:08 Prognosis Contrast: Angiosarcoma is aggressive with high mortality and requires extensive treatment, whereas KS is generally indolent and treated palliatively.
5:46 Biopsy Limitations: Small, superficial (shave) biopsies may be misleading, as the surface may only show benign findings (e.g., telangiectasia). Accurate clinical history (e.g., a growing, violaceous nodule) is essential for triggering suspicion.
6:22 Inflammation as an Obscuring Factor: Angiosarcomas often have significant background inflammation, which can make subtle atypical vascular channels difficult to spot.