#dermpathJC March 2020:
Thursday, March 26th, 9 pm EST
Article discussed: Angiosarcoma, Radiation-Associated Angiosarcoma, and Atypical Vascular Lesion
Authors: David R. Lucas
Open access courtesy of Archives of Pathology and Laboratory Medicine: https://www.archivesofpathology.org/doi/pdf/10.1043/1543-2165-133.11.1804
Summary prepared by: Cacey Peters, M.D. (@caceypeters)
Journal Club Summary:
Angiosarcoma general points:
- 1% of soft tissue sarcomas
- Associated with radiation therapy, most often breast cancer
- Also associated with chronic lymphedema, toxins (i.e. vinyl chloride), and foreign bodies (i.e. A/V fistulas)
- Usually presents as sporadic cutaneous tumor on scalp/face of elderly
- Reported in every anatomic site
- Bruise-like area that ulcerates or becomes nodular
- Often have smaller satellite lesions peripherally
- Clinically aggressive with high morbidity, regardless of grade
- Prognosis in sporadic cutaneous angiosarcoma correlates with high- and low- risk groups on the basis of age, epitheliod histology, necrosis, and tumor depth
- Deep tumors can be hemorrhagic spongelike or microcystic with necrosis
- Well-differentiated lesions can be deceptively bland, but will have some combination of hyperchromasia, mild pleomorphism, prominent nucleoli, mitotic figures, multilayering, and/or dermal collagen entrapment forming intraluminal papillary structures
- Surgical margins may be obscured by atypical lymphatic/capillary proliferations
- Moderate/poorly differentiated types will often have heterogeneous cytoarchitectural features
- Some combination of epithelioid, spindled, or pleomorphic cytology
- Some combination of vasoformative, sieve-like, kaposiform, or solid architecture
- Undifferentiated angiosarcoma will need immunohistochemistry to confirm the diagnosis
- CD31 = single best marker with high sensitivity and specificity
- Diffuse, intense staining with membranous accentuation
- Can be hard to interpret due to background blush, staining macrophages, and low-level expression in other tumor types
- CD 34 and factor VIII = present in most angiosarcomas but not reliably in poorly differentiated
- Cytokeratin pitfall = found in 35% of cases in one study (especially epithelioid angiosarcoma) although usually focal
- CD31 = single best marker with high sensitivity and specificity
Radiation-associated angiosarcoma
- Clinically and morphologically similar to sporadic angiosarcoma
- Latency is shorter for breast angiosarcoma
- 5-7 years on average
- Significant occurrence in less than 3 years which questions the 3-year rule
- More often cutaneous than sporadic angiosarcoma
- Erythematous plaque/patch/nodules with edema
- Diffuse, multifocal, and extensive involvement of the breast is common
- Median size = 7.5 cm
- Latency is shorter for breast angiosarcoma
Atypical Vascular Lesion (AVL):
- Benign course; can recur; rarely progress to angiosarcoma
- Tendency to develop further lesions, commonly AVLs
- Present as 1 or more small, flesh-colored papules or erythematous patches arising in radiated skin
- Histologically difficult to distinguish from well-differentiated angiosarcoma in a biopsy
- Often resemble lymphangiomas
- Well-demarcated proliferation of thin walled, dilated, interanastomosing channels without erythrocytes
- Lined by attenuated or hobnail endothelial cells without atypia
- Can resemble lymphangioendothelioma, lymphangioma circumscriptum, or both within the same lesion
- Most are limited to the superficial and mid dermis
- Current recommendations are to completely excise and follow for recurrence
Vascular-type AVL
- First described in 2005 with 3 cases that resemble lobular capillary hemangioma in mammary skin after radiation
- All 3 cases developed angiosarcoma
- In 2008, 8 more cases were described where only one developed angiosarcoma
It is suggested that vascular-type AVL is more likely to progress to angiosarcoma than the more common lymphatic-type AVL
Memorable tweets:
Stay safe my friends, and we will see you next month for another dermpath journal club,
With love,
DermpathJC