66 yo female presented with the recent onset of asymptomatic red papules on her right breast developing over 1 week. Right sided breast cancer in 2005 treated with lumpectomy of the right breast, resection of right axillary lymph nodes, followed by radiation therapy and chemotherapy. A diagnosis of atypical vascular proliferation consistent with post-radiation atypical vascular lesion

Laboratory Data

Hepatitis C, Hepatitis B, HIV - negative in 2010
RPR negative, ANA < 40 in 2008

2 biopsy sites showed similar processes.

Scanning view

x 200

x 400

Lesions are rather circumscribed but have dissecting periphery.  The atypia appears insufficient for diagnosis of well-differentiated angiosarcoma. Ki67 proliferative index is low.  Immunohistochemical stains show expression of CD31 but HHV-8 is not expressed.
Sections revealed an aggregate of arborizing, variably sized and dilated vascular channels lined by plump endothelials cells in the superficial dermis with extravasation of red blood cells.  In focal areas, vascular channels appear to dissect the surrounding slightly fibrotic collagen.  No apparent abnormal fibroblasts.

Atypical vascular proliferation consistent with post-radiation atypical vascular lesion

Given a potential risk for malignant tranformation in atypical vascular lesions of the breast for a patient with multiple scattered papules across her right breast / chest:
Would imiquimod field therapy to the irradiated and involved area provide results and for what duration? 

Should remaining lesions be excised individually and with what margins?
Should imiquimod be utilized prior to further surgery or following further surgical interventions?
Would other medical therapies prevent possible progression of these lesions?

1. Mandrell J, Mehta S, McClure S. Atypical vascular lesion of the breast. J Am Acad Dermatol Aug 2010 Aug; 63(2):337-340
   Abstract Full Text PDF (1 MB)
   
   
2. Gengler C, Coindre JM, Leroux A, Trassard M, Ranchère-Vince D, Valo I, Michels JJ, Guillou L. Vascular proliferations of the skin after radiation therapy for breast cancer: clinicopathologic analysis of a series in favor of a benign process: a study from the French Sarcoma Group. Cancer. 2007 Apr 15;109(8):1584-98
   Abstract Full Text PDF (2MB)
   
   
3. Lucas D. Angiosarcoma, Radiation-Associated Angiosarcoma, and
   Atypical Vascular Lesion Arch Pathol Lab Med. 2009;133:1804–1809
   Abstract Full Text PDF(6MB)
   
   
4. Luis Requena, Heinz Kutzner, Thomas Mentzel, Rafael Durán, and José Luis Rodríguez-Peralto. Benign Vascular Proliferations in Irradiated Skin. Am J Surg Pathol 26(3): 328–337, 2002.
   Abstract Full Text PDF(3 MB)

atypical vascular lesions, breast cancer, angiosarcoma

Ron Yaar MD, PhD, Assistant Professor, Director of Dermatopathology Training, Boston Medical Centre, Department of Dermatology, Dermatopathology Section, Boston, MA, USA on October 26, 2010

We all agree that this looks like the entity described variably as atypical vascular lesion of irradiated skin or benign lymphangiomatous papules.

I've attached some literature I found regarding this diagnosis.    While relatively few cases have been described, it appears that the consensus is that these appear to behave in a benign fashion and do not represent precursors for angiosarcoma. (For further reference see presentation above )

Samuel Moschella MD, Professor of Dermatology, Emeritus, Harvard Medical School, Senior Consultant, Lahey Clinic, Burlington, MA, USA on October 28, 2010

I am aware of the disease and have heard discussions and the consensus about therapy was a trial with imiquimod (ALDARA).

Khaled El-hoshy M.D., Consultant Dermatologist, Troy, Michigan, USA on October 28, 2010

I would definitely re-biopsy another lesion in 1 month or so & keep a very close f/u. Angiosarcoma, or even metastatic breast CA, is a real possibility. I am not in favor of Imiquimod. I think it is a weak agent in such a case.

Bashir Zendah MD, Senior Registrar, Department of Dermatology, Tripoli Medical Centre, Tripoli, Libya on October 28, 2010

I agree with the opinion of Dr. Khaled because the spectrum of postradiation vascular lesions is wide and ranges from atypical vascular lesions with reportedly benign clinical behaviour to frank cutaneous angiosarcoma. There is, however, significant clinical as well as histological overlap. It is frequently difficult to classify these postradiation vascular lesions accurately and they create an emerging diagnostic and therapeutic challenge to both pathologists and clinicians. Experience with these vascular lesions is very limited.

Adel Aly MD, Dermatologist, Cairo, Egypt on October 29, 2010

I doubt imiquimod would work for a vascular lesion with malignant potential. From the review of literature it appears that cases developing into post-radiation angiosarcoma are older in age, having vascular type and larger size of the lesion (7.5 cm). Current recommendations include complete excision and f/u for any new lesion.