Diagnostic difficulties of primary angiosarcoma of the breast: a case report.

Background: Angiosarcoma of the breast is a rare tumor, which may be primary or secondary to breast surgery or irradiation. It is characterized by polymorphic and nonspecific clinical and radiological features. A pathologist plays a key role in positive and differential diagnosis and in establishing the prognosis: only a histological examination can confirm the diagnosis, and the histologic grade is the most important prognostic factor. In fact, angiosarcomas of the breast constitute a very heterogeneous group and they are classified into three grades based on the degree of differentiation. We will illustrate diagnostic challenges through this new case of primary angiosarcoma of the breast. Microscopic findings were initially interpreted as a benign vascular tumor. We will also discuss the relevant medical literature.

Case Presentation: A 56-year-old Arabian woman presented with a palpable right breast mass that had been enlarging for 2 months, measuring 5 cm, without axillary lymphadenopathy. She had no personal or family history of breast surgery or breast irradiation. A mammography showed no evidence of spiculation. No suspicious calcifications were seen. A needle core biopsy was performed. Microscopic findings were initially interpreted as a benign vascular tumor. However, as the mass measured 5 cm, the diagnosis of angiosarcoma was more appropriate, and mastectomy without axillary dissection was performed. Microscopic examination found mild to moderately scattered pleomorphic cells, and scattered mitotic figures. It also showed papillary formations, solid foci of spindle cells, and hemorrhagic necrosis. The margins of the tumor were infiltrative. The diagnosis of primary intermediately differentiated angiosarcoma of the breast (grade II) was made. No distant metastases were found. Our patient was lost to follow-up and further treatment after mastectomy until she developed local tumor progression 4 months later.

Conclusions: Through this case report, we emphasize the importance of clinicopathological confrontation in angiosarcoma of the breast.