Case Number : Case 1954 - 24 Nov 2017 Posted By: Dr. Richard Carr

Difficult. The sample doesn't contain subcutaneous fat and it's difficult to assess the real size and circumscription of the lesion. My first spot is ST-Angiosarcoma because of:

1) Lesion is on arm, which isn't an irradiation field.

2) Lesion looks like a poorly circumscribed growth, without well delimited edges.

3) Lesion is growing also in deep dermis.

4) Vessels in AVL are usually top-open and bottom-narrow...here it seems the opposite.

But this one is a true diagnostic challenge!!!

Agree with Vincenzo. Vascular spaces lined with plump endothelial cells dissecting the collagen in dermis. A well differentiated angiosarcoma in a lymphedematous limb- (Stewart Treves)

Angiosarcoma (Stewart-Treves)

4 hours ago, vincenzo polizzi said:

Difficult. The sample doesn't contain subcutaneous fat and it's difficult to assess the real size and circumscription of the lesion. My first spot is ST-Angiosarcoma because of:

1) Lesion is on arm, which isn't an irradiation field.

2) Lesion looks like a poorly circumscribed growth, without well delimited edges.

3) Lesion is growing also in deep dermis.

4) Vessels in AVL are usually top-open and bottom-narrow...here it seems the opposite.

But this one is a true diagnostic challenge!!!

Agree. It's in the setting of lymphedema, so well differentiated angiosarcoma.

First of all this is probably a post-radiation vascular lesion although the location on the arm is unusual. But with a history of breast cancer and radiation, we have to assume the vascular lesion is related (lymphedema or post radiation)

The vascular channels are very irregular so I would not favor pure lymphangiectasia in the context of lymph edema.

So the differential diagnosis is between post radiation atypical vascular lesion vs. angiosarcoma.

To me, the lining endothelial cells are atypical but not in the degree of angiosarcoma (very subjective, but no really hob nailing or epithelioid), no mitoses, and not a lot of atypical vessels. So I favor post radiation atypical vascular lesion. The clinical pictures might help and FISH or IHC for c-myc might also be helpful. c-myc amplification has been reported in secondary angiosarcoma but not in atypical vascular lesion.

Hi All. What a challenging case. Just on histology without the site information but history of radiation I would have considered Radiation-associated cutaneous atypical vascular lesion. In Thomas Brenn's paper (https://www.ncbi.nlm.nih.gov/pubmed/16006792) he describes lesions on chest wall (35), abdomen (2), shoulder, groin, flank, axilla, and lower leg (1 each). Radiation was not only for breast cancer but 'a variety of other lesions (mainly malignant disease)'.  So the site is not typical but doesnt exclude radiation! Also in the images the borders are difficult to define on this biopsy. It certainly has some features of AVL but going against this is having the lesion confined within superficial to mid dermis. 

Based on the above I would go for a well differentiated angiosarcoma in the setting of lymphoedema. 

For me well diff angiosarcoma in the setting of lymphedema

I consider post-radiation vascular lesion. cMYC Immunohistochemistry is a very good help

Thanks for all the worthy suggestions and comments.

The submitted diagnosis is: Benign lymphangioendothelioma (acquired progressive lymphangioma) in the setting of lymphoedema secondary to the previous treatment for breast cancer. I suppose clinical features are essential for the diagnosis and the distinction from Stewart Treve's (lymph)angiosarcoma can be exceedingly difficult. This lesion was not in the field of radiotherapy.

Tough case!

Was c-myc study performed in this case? In this case I would certainly do it.