Mammography and MRI manifestations of breast angiosarcoma

We collected the clinical and imaging data of 17 female patients with breast angiosarcoma (15 with PBA and 2 with SBA) which was pathologically confirmed in five hospitals (including our hospital) from April 2005 to June 2018. The 17 patients’ mean age was 34.6 years (range: 17–48). Among the 15 patients with PBA, 14 did not have any precursor disease and no similar lesions were found on the other body parts, while the other 1 had bruises on the skin of her affected breast. The bruises were caused by a hard object one year before the study. The injured skin became dark, swollen and indurated, and anti-inflammatory treatment did not improve the condition. The two cases of SBA developed this disease secondarily to angiosarcoma of other body parts (the cervical vertebra and the liver, respectively).

The patients had PBA/SBA 2 to 16 months ago, and the masses became progressively more swollen. Four patients suffered severe breast pain. Five cases had purplish-red breast skin, and three of them experienced edema of the affected breast. No skin ulcers or varicose veins were found in any patients. The results of surgical pathological examination showed that the average maximum diameter of the tumors was 8.6 cm (range: 4–16.5).

Eight patients underwent preoperative mammography in a standing position with GE Digital Senographe 2000D Mammography (GE Healthcare, Waukesha, Wisconsin) and Siemens Mammomat Novation DR (Siemens Healthcare, Erlangen, Germany) under automatic exposure mode. Both the craniocaudal (CC) and mediolateral oblique (MLO) views were examined. Thirteen patients underwent MRI scan using GE Signa HDx 3.0 T MRI machine with dedicated breast surface coils. Non-enhanced imaging: T1WI: TR/TE = 800/8 ms, STIR: TR/TE = 3300/85 ms, the slice thickness = 6 mm, the matrix = 320 × 192; dynamic contrast-enhanced gradient-echo imaging: T1WI: TR/TE = 4.2/2.1 ms, the flip angle = 10 °, the slice thickness = 4 mm, the matrix = 384 × 256, the NEX = 1, the FOV = 30 × 38 cm². Gd-DTPA of 0.1 mmol/kg was injected into the median cubital vein as the contrast agent. Enhanced scan was done before the injection of Gd-DTPA and 1, 2, 4, and 7 min after it.

Necrosis, cystic degeneration and hemorrhagic regions were avoided to be included in the enhancement curves. The morphology, diameter, components, and margins of the tumors, skin changes and the condition of the axillary lymph nodes were analyzed retrospectively by two radiologists who had practiced imaging diagnosis of breast diseases for more than five years. They had no access to patients’ previous clinical records and reached a consensus through discussion when they had different opinions.

The samples were fixed, decalcificated, stained with hematoxylin-eosin (HE), and then examined with optical microscope. Classification of the samples was done according to immunohistochemistry results. The sections were examined by two senior professors who had practiced pathological diagnosis of breast tumors for more than 15 years.

Among the 8 patients who underwent mammography (Table 1), 5 cases presented with deep-seated lobular or oval masses (Fig. 1). Three patients’ mammograms showed huge asymmetrical mass shadow that occupied two or more quadrants and fused together with linear low-density parts, poorly marginated lesions, and trabecular thickening of surrounding tissues (Fig. 4a). The margins of masses were not smooth, and some of them were even obscured. Skin edema was found in 2 cases. All the 8 cases did not experience calcification or swollen axillary lymph nodes.

Thirteen patients received preoperative MRI scan (Table 2). Lesions had slightly/significantly high homogeneous or heterogeneous signals on T1-weighted images (Fig. 2a, 3a). Necrosis and cystic degeneration exhibited relatively low signals. Hemorrhagic lesions were found in 7 cases and had high signals on T1-weighted and T2-weighted images (Fig. 2a, 3a, b). The hemosiderin ring resulted from long-term hemorrhage had long and short signals on T1- and T2-weighted images, respectively (Fig. 3a, b: white arrow). Three patients suffered from edema, thickening, and cloudy subcutaneous fat of the breast skin. Contrast-enhanced images revealed significant heterogeneous enhancement of all lesions (Figs. 2, 3, 4 and 5). Significant enhancement was observed in the early phases, and concentric enhancement at different degrees was seen in the delayed phase (Figs. 2, 3). The dynamic contrast enhancement curves of most cases were in a persistently enhancing or plateau pattern, while the curve of one patient was in a washout pattern. One patient’s lesions were enhanced in a non-mass-like form, and had no well-defined margins (Fig. 5). The patient’s dynamic contrast enhancement curve was in a persistently enhancing pattern.

All the lesions of the 17 cases were located in the breast parenchyma. These soft lesions with fish-meat- or sponge-like cross sections were rich in blood, and had no capsules and well-defined margins. However, different regions had different characteristics and the characteristics also varied with the differentiation degree of tumor tissues. Lesions were characterized by irregular capillary lumens. The poorer the differentiation was, the more common atypia and nuclear division in vascular endothelial cells were. Blood lakes resulted from excessive hemorrhage were seen, while the vascular compartment and breast ducts were hardly observed.

The 17 patients’ pathological sections showed no metastasis to axillary lymph nodes. The patients received modified radical mastectomy or simple mastectomy, followed by adjuvant radiotherapy and chemotherapy. Follow-up was conducted with 12 patients. One case was found to have metastatic tumors in multiple vertebral bodies and the pelvis while receiving a bone scan 14 months after surgery. Abdominal CT scan indicated no abnormalities, and breast ultrasound revealed no local recurrence. The patient then received nine courses of chemotherapy. Bone scan, abdominal CT scan and mammography done 25 months after surgery indicated no new lesions. Pulmonary metastasis was observed in 1 case 7 months after surgery, while metastases to the cervical spine and lung was found in another patient 19 months after surgery. Three patients died 25 to 41 months after surgery (2 from multiple organ failure). No recurrence or distant metastasis was found in the other six patients who had been followed up for 9 to 21 months. Five patients were lost to follow-up and they could not be contacted by telephone.

Breast angiosarcoma presenting as masses or asymmetry dense lesions should be firstly differentiated from breast cancer which has various forms. The median age of onset for breast cancer (more than 40 to 50 years) is older than that for breast angiosarcoma. Breast angiosarcoma should be further differentiated from breast inflammation. The two kinds of diseases share several common things in the clinical symptoms, age of onset, and imaging manifestations, which makes differentiation difficult. However, breast angiosarcoma cannot be relieved by anti-inflammatory treatment. Breast angiosarcoma should also be differentiated from breast lymphoma. The imaging manifestations of breast lymphoma are nonspecific and the age of onset for this disease is similar to that for breast angiosarcoma. Patients with breast lymphoma have a higher incidence to present with swollen axillary lymph nodes, which can help the differentiation between the two breast diseases. Besides, a breast angiosarcoma presenting as a solitary mass should be also differentiated from phyllodes tumor.