A Rare Tumor that Mimicked Metastasis in a Patient with Breast Cancer: Epithelioid Hemangioendothelioma

Abstract

A woman aged 50 years was diagnosed as having an invasive ductal carcinoma in the right breast and ductal carcinoma in situ in the left breast and underwent bilateral mastectomy eight years ago. A mass was identified during follow-up in positron-emission tomography (PET) image in the left infraclavicular region, indicating metastasis. Histopathologic examination showed a mass of 1.9 x 1 x 0.7 cm in dimensions characterized by spindle or round nuclei cells that formed island or cords in hyaline and myxoid ground and intracytoplasmic vacuoles containing erythrocytes. In the immunohistochemical analysis, tumor cells were widespread with diffuse positivity with CD34 and vimentin. These findings redirected us from a diagnosis of metastatic carcinoma to epithelioid hemangioendothelioma, a rare tumor of intermediate vascular tumor groups. In this respect, confirmation through biopsy from considered cases of metastasis is important in making a definite pathologic differential diagnosis.

Case of epithelioid hemangioendothelioma occurring in the postradiation setting for breast cancer

“…23 Another case of EHE was reported in a 50-year-old woman who underwent bilateral mastectomy for HER2-positive breast cancer 8 years prior to the identification of an infraclavicular soft tissue mass diagnosed as EHE; the patient did not receive radiotherapy (only Herceptin and adjuvant chemotherapy). 24 Our case was confirmed as EHE by RNA sequencing with identification of the characteristic fusion. Although this occurred significantly sooner than would be expected for a radiation-associated malignancy (3-year interval), the role of radiation in the oncogenesis of this lesion remains uncertain.…”

“…[18][19][20][21] Review of the literature regarding EHE and associations with breast site and cancer revealed two cases of extra mammary EHE in patients with history of breast cancer and one report of EHE in the breast in an otherwise healthy 30-year-old patient, none of which were confirmed with molecular testing. [22][23][24] One case is described in a 57-year-old woman who underwent mastectomy for node positive breast carcinoma without adjuvant radiation and went on to develop EHE 20 years later. 23 She had delayed reconstruction with saline followed by silicone implants and presented with multiple lung and liver lesions that were ultimately diagnosed as EHE.…”