Atypical or benign vascular lesion, post radiation

Breast - nonmalignant
Benign tumors / changes
Atypical or benign vascular lesion, post radiation

Author: Monika Roychowdhury, M.D. (see Authors page)

Revised: 23 November 2016, last major update November 2016

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed Search: Post radiation atypical vascular lesions

Table of Contents

Cite this page: Atypical or benign vascular lesion, post radiation. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/breastatypicalvascular.html. Accessed July 14th, 2017.

Definition / general

Vascular proliferations that develop after external radiotherapy for breast carcinoma, within field of radiation (Am J Clin Path 1994;102:757)

Essential features

Benign atypical vascular proliferations developing after external radiation for breast carcinoma
Typically involves skin overlying breast
Two types: 1) Lymphatic type; 2) Vascular type
Differentiate from angiosarcoma by well circumscribed nature, lack of multi layering, mitosis and hemorrhage and absence of extension into subcutaneous tissue
Vascular type is higher risk for subsequent development of angiosarcoma
Complete excision and follow up for recurrence is standard treatment

Terminology

“Atypical vascular lesion” term coined by Fineberg and Rosen in 1994 (Am J Clin Path 1994;102:757)
Note: atypical vascular pattern refers to a dermoscopic pattern that helps differentiate benign cutaneous lesions from melanoma

Epidemiology

Mean age 61 years
Develops 1 - 12 years (mean 6 years) after therapy in radiation field

Sites

Breast exposed to previous radiation, usually in the skin area

Etiology

May have lymphatic origin (Histopathology 1999;35:319)

Clinical features

May recur within radiation field (Cancer 2007;109:1584)

Prognostic factors

May progress to angiosarcoma, particularly vascular type (Am J Surg Pathol 2008;32:943, Am J Surg Pathol 2005;29:983)

Case reports

Two women, ages 42 and 50 year old, with post radiation atypical vascular lesions of breast (Case Reports in Pathology 2012:2012;710318)
49 year old woman with post radiation atypical vascular proliferation (J Clin Aesthet Dermatol 2011;4:47)

Treatment

Complete excision and careful follow up for recurrence

Clinical images

Images hosted on other servers:

Left breast is erythematous with sclerotic tissue changes

Figs 1 and 4: Papules and nodules in and around the mastectomy scar

Gross description

One or more circumscribed papules, bluish purple nodules, small vesicles or erythematous plaques, usually in irradiated field, median 0.5 cm
Frequently multiple synchronous lesions with discoloration

Microscopic (histologic) description

Relatively well circumscribed, anastomosing growth pattern of irregular slit-like vascular spaces dissecting dermal collagen but not extending into subcutis
Lined by single layer of endothelial cells without atypia
Often micropapillary tufts
Resembles benign lymphangioendothelioma or patch stage Kaposi sarcoma (Am J Surg Pathol 2002;26:328)

Lymphatic type

Predominantly thin walled, variably anastomosing lymphatics primarily in superficial dermis

Vascular type

Predominantly small, irregularly dispersed, capillary type vessels, invested by pericytes, often blood filled, in superficial or deep dermis
Associated with extravasated red blood cells or hemosiderin, minor lymphatic type component (Arch Pathol Lab Med 2009;133:1804)
Higher risk for angiosarcoma (Am J Dermatopathol 2005;27:301, Am J Surg Pathol 2008;32:943)

Features of angiosarcoma which are lacking in AVLs

Multi layering of endothelial cells, prominent nucleoli, mitoses, hemorrhage, destruction of adnexa and extension into subcutaneous tissues

Microscopic (histologic) images

Images hosted on other servers:

Figures 9 - 11

H&E, CD31 and FLI1

Lesions confined to papillary and reticular dermis

Dermis showed perivascular lymphocytic infiltrate and collagenization

Positive stains

CD31, D2-40
Variable CD34

Negative stains

c-MYC

Molecular / cytogenetics description

No MYC amplification (Mod Pathol 2012;25:75)

Differential diagnosis

Angiosarcoma, well differentiated:
- Atypical endothelial cells, infiltrative margins, usually high grade, larger (median 7.5 cm vs. 0.5 cm for atypical vascular lesions), positive nuclear staining for c-MYC
- Atypical vascular lesions are well circumscribed, not infiltrative, no multi layering, no mitosis, no hemorrhage
- However, angiosarcoma may be part of morphologic continuum with atypical vascular lesions (J Am Acad Dermatol 2007;57:126), and may need additional biopsies to distinguish these entities
Hobnail hemangioma: smaller, more superficial and more localized
Lymphangioendothelioma: has intravascular papillary stromal projections that resemble papillary endothelial hyperplasia