PECAM1 and neoplasm: Subsequent USG-guided core biopsy showed a tumor composed of epithelioid cells with cytoplasmic vacuolation, hypochromasia, and pleomorphism, confirming the diagnosis of HEHE. Immunohistochemical staining of tumor cells was positive for cluster of differentiation-34 (CD34), cluster of differentiation-31 (CD31), and estrogen receptors.